JP2006090814A - Optical network analyzer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical network analyzer which can determine the propagation characteristics of an object to be measured, with high accuracy. <P>SOLUTION: The optical network analyzer comprises a demultiplexer for demultiplexing an optical signal generated by a light source; a first polarization controller for converting the polarization angle of one of the demultiplexed optical signal and allowing it to enter the object to be measured; an optical frequency converter for converting the frequency of the other of the demultiplexed optical signal; a second polarization controller for converting the polarization angle of the optical signal, of which the optical frequency has been converted; a multiplexer for multiplexing the optical signal passed through the object to be measured with the optical signal of which the polarization angle converted by the second polarization controller and outputting it; a polarization separation optoelectronic converter for outputting electrical signals, indicating a horizontally polarized component and a vertically polarized component included in the optical signal outputted by the multiplexer, respectively; and a network analyzer for determining the propagation characteristics of the object to be measured, on the basis of the reference signal generated by a reference signal generator and the electrical signals outputted by the polarization separation optoelectronic converter. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical network analyzer. In particular, the present invention relates to an optical network analyzer that obtains propagation characteristics of an object to be measured.

  FIG. 1 shows the configuration of an optical network analyzer 100 according to the prior art. The optical network analyzer 100 includes an optical measurement unit 101 and a network analyzer 102. The optical measurement unit 101 includes a wavelength tunable light source 104, a duplexer 106, a frequency converter 108, a reference high-frequency signal source 110, a multiplexer 112, and a photoelectric converter 114. The network analyzer 102 includes a phase amplitude comparator 116 and an averaging processing unit 118.

  The wavelength variable light source 104 generates an optical signal. The demultiplexer 106 demultiplexes the optical signal generated by the wavelength tunable light source 104 generated by the wavelength tunable light source 104, and enters one of the demultiplexed optical signals into the DUT 10. The reference high-frequency signal source 110 generates a reference signal having a predetermined frequency lower than the optical frequency of the optical signal, and supplies the reference signal to the signal input port B of the frequency converter 108 and the phase amplitude comparator 116. The frequency converter 108 converts the frequency of the other optical signal demultiplexed by the demultiplexer 106 based on the reference signal generated by the reference high-frequency signal source 110.

  The multiplexer 112 multiplexes and outputs the optical signal incident on the device under test 10 by the duplexer 106 and transmitted through the device under test 10, and the optical signal whose frequency has been converted by the frequency converter 108. . The photoelectric converter 114 converts the optical signal output from the multiplexer 112 into an electrical signal and supplies the electrical signal to the signal input port A of the phase amplitude comparator 116.

  The phase amplitude comparator 116 compares the electrical signal, which is a heterodyne interference signal supplied from the photoelectric converter 114 to the signal input port A, with the reference signal supplied from the reference high-frequency signal source 110 to the signal input port B. Measure the phase and amplitude of the heterodyne interference signal. Then, the averaging processing unit 118 performs an averaging process on the measurement values measured by the phase amplitude comparator 116. Then, the network analyzer 102 obtains the loss wavelength characteristic, the group delay characteristic, and the chromatic dispersion characteristic of the device under test 10 based on the output data of the averaging processing unit 118 (see, for example, Patent Document 1).

  FIG. 2 shows a configuration of an optical network analyzer 200 according to the prior art. The optical network analyzer 200 includes an optical measurement unit 201 and a network analyzer 202. The optical measurement unit 201 includes a wavelength tunable light source 204, a light intensity modulator 206, a reference high-frequency signal source 208, a polarization control unit 210, a polarization demultiplexer 212, a photoelectric converter 214, and a photoelectric converter 216. The network analyzer 202 includes a phase / amplitude comparator 218, an A / D converter 220, and a data processing block 222.

  The wavelength variable light source 204 generates an optical signal. The reference high-frequency signal source 208 generates a reference signal having a predetermined frequency lower than the optical frequency of the optical signal, and supplies the reference signal to the signal input port C of the optical intensity modulator 206 and the phase amplitude comparator 116. The light intensity modulator 206 intensity-modulates the optical signal generated by the variable wavelength light source 204 based on the reference signal generated by the reference high-frequency signal source 208. Then, the polarization control unit 210 converts the polarization angle of the optical signal whose intensity is modulated by the polarization control unit 210 and enters the device under test 10.

  The polarization demultiplexer 212 divides an optical signal incident on the device under test 10 and transmitted through the device under test 10 by the polarization controller 210 into an optical signal of a horizontal polarization component and an optical signal of a vertical polarization component. To wave. The photoelectric converter 214 converts the optical signal of the horizontal polarization component demultiplexed by the polarization demultiplexer 212 into an electric signal and supplies the electric signal to the signal input port A of the phase amplitude comparator 218. Further, the photoelectric converter 216 converts the optical signal of the vertical polarization component demultiplexed by the polarization demultiplexer 212 into an electric signal, and supplies it to the signal input port B of the phase amplitude comparator 218.

  The phase / amplitude comparator 218 receives an electric signal supplied from the photoelectric converter 214 to the signal input port A, an electric signal supplied from the photoelectric converter 216 to the signal input port B, and a signal input from the reference high-frequency signal source 208. The reference signal supplied to the port C is compared, and the phase and amplitude of the optical signal of the horizontal polarization component and the optical signal of the vertical polarization component included in the optical signal transmitted through the device under test 10 are measured. Then, the A / D converter 220 converts the measurement value measured by the phase amplitude comparator 218 into digital data. Then, the data processing block 222 sends the loss wavelength characteristic, group delay characteristic, wavelength dispersion characteristic, differential group delay characteristic, and polarization mode dispersion characteristic of the DUT 10 based on the output data to the A / D converter 220. (For example, refer nonpatent literature 2).

International Publication No. 02/082038 Pamphlet Eiji Kimura, “Polarization Mode Dispersion Measurement Technology”, Probo, 2001, No. 18, p. 17-22

  In the optical network analyzer 100 according to the prior art shown in FIG. 1, the loss wavelength characteristic, group delay characteristic, and chromatic dispersion characteristic of the DUT 10 can be obtained with high accuracy and high resolution. There is a problem that polarization characteristics such as polarization mode dispersion characteristics cannot be obtained.

  In the optical network analyzer 200 according to the prior art shown in FIG. 2, the light intensity converter 206 is provided between the wavelength variable light source 204 and the device under test 10, so that the light incident on the device under test 10. There is a problem that a side mode occurs in the spectrum of the signal and the resolution of the measurement value of the phase amplitude comparator 218 is limited. Further, there is a problem that the chirp amount of the light intensity modulator 206 causes a measurement error in the phase measurement by the phase amplitude comparator 218.

  Therefore, an object of the present invention is to provide an optical network analyzer that can solve the above-described problems. This object is achieved by a combination of features described in the independent claims. The dependent claims define further advantageous specific examples of the present invention.

  According to the first aspect of the present invention, a light source that generates an optical signal, a first demultiplexer that demultiplexes the optical signal generated by the light source, and one of the optical signals demultiplexed by the first demultiplexer. Based on the first reference signal, the first polarization controller that converts the polarization angle and enters the device under test, the first reference signal generator that generates the first reference signal having the first frequency, and the first reference signal. A first optical frequency converter that converts the optical frequency of the other optical signal demultiplexed by the demultiplexer, and a second polarization that converts the polarization angle of the optical signal whose optical frequency has been converted by the first optical frequency converter. A wave controller, an optical signal incident on the object to be measured by the first polarization controller and transmitted through the object to be measured, and an optical signal whose polarization angle is converted by the second polarization controller. The output multiplexer and the horizontal polarization component and vertical polarization component included in the optical signal output by the multiplexer are shown. Based on the polarization separation photoelectric conversion unit that outputs the air signal, the first reference signal generated by the first reference signal generation unit, and the electrical signal output by the polarization separation photoelectric conversion unit, the propagation characteristics of the device under test are determined. A network analyzer to be obtained.

  The polarization separation photoelectric conversion unit demultiplexes the optical signal output from the multiplexer into a horizontal polarization component optical signal and a vertical polarization component optical signal, and a polarization demultiplexer. A first photoelectric converter that converts the optical signal of the horizontally polarized component into an electric signal, and a second photoelectric converter that converts the optical signal of the vertical polarization component demultiplexed by the polarization demultiplexer into an electric signal, You may have.

  A first frequency divider that divides the electrical signal converted by the first photoelectric conversion unit and supplies it to the network analyzer, and is converted by the second photoelectric conversion unit at the same frequency division ratio as the first frequency divider. A second frequency divider that divides the electrical signal and supplies it to the network analyzer, and a first reference signal generated by the first reference signal generator at the same frequency division ratio as the first frequency divider. You may further provide the 3rd frequency divider supplied to a network analyzer.

  Based on a second demultiplexer that demultiplexes the other optical signal demultiplexed by the first demultiplexer, a second reference signal generator that generates a second reference signal having a second frequency, and a second reference signal A second optical frequency converter for converting the optical frequency of one of the optical signals demultiplexed by the second demultiplexer, and a polarization angle of the optical signal whose optical frequency is converted by the second optical frequency converter. The third polarization controller, the optical signal whose polarization angle is converted by the second polarization controller, and the optical signal whose polarization angle is converted by the third polarization controller are combined and output. A first optical frequency converter that converts the optical frequency of the other optical signal demultiplexed by the second demultiplexer based on the first reference signal, the multiplexer The optical signal that has been incident on the object to be measured and transmitted through the object to be measured by the first polarization controller and the polarization multiplexer outputs An optical signal may be multiplexed.

  The polarization separation photoelectric conversion unit is a polarization demultiplexer that demultiplexes the optical signal output from the multiplexer into an optical signal of a horizontal polarization component and an optical signal of a vertical polarization component, and is demultiplexed by the polarization demultiplexer. A first photoelectric converter that converts the optical signal of the horizontally polarized component into an electric signal, and a second photoelectric converter that converts the optical signal of the vertical polarization component demultiplexed by the polarization demultiplexer into an electric signal, You may have.

  A first frequency divider that divides the electrical signal converted by the first photoelectric conversion unit and supplies it to the network analyzer, and is converted by the second photoelectric conversion unit at the same frequency division ratio as the first frequency divider. A second frequency divider that divides the electrical signal and supplies it to the network analyzer, and a first reference signal generated by the first reference signal generator at the same frequency division ratio as the first frequency divider. A third divider supplied to the network analyzer and a fourth divider that divides the second reference signal generated by the second reference signal generator with the same division ratio as the first divider and supplies the second reference signal to the network analyzer. A frequency divider may be further provided.

  A photoelectric converter that converts an optical signal output from the multiplexer into an electrical signal, and an electrical signal that indicates a horizontal polarization component included in the optical signal output from the multiplexer from the electrical signal converted by the photoelectric converter. A second bandpass filter that separates and outputs an electric signal indicating a vertical polarization component included in an optical signal output from the multiplexer from a first band pass filter that outputs the separated signal and an electric signal converted by the photoelectric converter. A band transmission filter may be further provided.

  A first frequency divider that divides the electrical signal output from the first band pass filter and supplies it to the network analyzer, and an electrical signal output from the second band pass filter at the same frequency division ratio as the first frequency divider A second frequency divider that divides and supplies the first reference signal generated by the first reference signal generator at the same frequency division ratio as that of the first frequency divider. A third frequency divider for supplying to the first frequency divider and a fourth frequency divider for dividing the second reference signal generated by the second reference signal generator and supplying the same to the network analyzer at the same frequency division ratio as the first frequency divider. And a vessel.

  According to the second aspect of the present invention, a light source that generates an optical signal, a first demultiplexer that demultiplexes the optical signal generated by the light source, and one of the optical signals demultiplexed by the first demultiplexer. Based on the first reference signal, the first polarization controller that converts the polarization angle, the first reference signal generation unit that generates the first reference signal having the first frequency, and the first reference signal to be demultiplexed. A first optical frequency converter that converts the optical frequency of the other optical signal, and a second polarization that converts the polarization angle of the optical signal whose optical frequency has been converted by the first optical frequency converter and enters the object to be measured. A wave controller, an optical signal whose polarization angle is converted by the first polarization controller, and an optical signal which is incident on the measured object and transmitted through the measured object by the second polarization controller. An electrical signal indicating the horizontal polarization component and the vertical polarization component included in the optical signal output from the wave multiplexer and the multiplexer. A network analyzer that obtains propagation characteristics of the device under test based on the output polarization separation photoelectric conversion unit, the first reference signal generated by the first reference signal generation unit, and the electrical signal output by the polarization separation photoelectric conversion unit With.

  Based on a second demultiplexer that demultiplexes the other optical signal demultiplexed by the first demultiplexer, a second reference signal generator that generates a second reference signal having a second frequency, and a second reference signal A second optical frequency converter for converting the optical frequency of one of the optical signals demultiplexed by the second demultiplexer, and a polarization angle of the optical signal whose optical frequency is converted by the second optical frequency converter. The third polarization controller, the optical signal whose polarization angle is converted by the second polarization controller, and the optical signal whose polarization angle is converted by the third polarization controller are combined to be measured. A first optical frequency converter that converts an optical frequency of the other optical signal demultiplexed by the second demultiplexer based on the first reference signal, The multiplexer includes an optical signal whose polarization angle is converted by the first polarization controller, and an object to be measured by the polarization multiplexer. It is incident may multiplexes the optical signal transmitted through the DUT.

  The polarization separation photoelectric conversion unit demultiplexes the optical signal output from the multiplexer into a horizontal polarization component optical signal and a vertical polarization component optical signal, and a polarization demultiplexer. A first photoelectric converter that converts the optical signal of the horizontally polarized component into an electric signal, and a second photoelectric converter that converts the optical signal of the vertical polarization component demultiplexed by the polarization demultiplexer into an electric signal, You may have.

  A first frequency divider that divides the electrical signal converted by the first photoelectric conversion unit and supplies it to the network analyzer, and is converted by the second photoelectric conversion unit at the same frequency division ratio as the first frequency divider. A second frequency divider that divides the electrical signal and supplies it to the network analyzer, and a first reference signal generated by the first reference signal generator at the same frequency division ratio as the first frequency divider. A fourth divider that divides the second reference signal generated by the second reference signal generator and supplies it to the network analyzer at the same division ratio as the third divider and the first divider supplied to the network analyzer. A peripheral may be further provided.

  A photoelectric converter that converts an optical signal output from the multiplexer into an electrical signal, and an electrical signal that indicates a horizontal polarization component included in the optical signal output from the multiplexer from the electrical signal converted by the photoelectric converter. A second bandpass filter that separates and outputs an electric signal indicating a vertical polarization component included in an optical signal output from the multiplexer from a first band pass filter that outputs the separated signal and an electric signal converted by the photoelectric converter. A band transmission filter may be further provided.

  A first frequency divider that divides the electrical signal output from the first band pass filter and supplies it to the network analyzer, and an electrical signal output from the second band pass filter at the same frequency division ratio as the first frequency divider A second frequency divider that divides and supplies the first reference signal generated by the first reference signal generator at the same frequency division ratio as that of the first frequency divider. A third frequency divider for supplying to the first frequency divider and a fourth frequency divider for dividing the second reference signal generated by the second reference signal generator and supplying the same to the network analyzer at the same frequency division ratio as the first frequency divider. And a vessel.

According to the third aspect of the present invention, a light source that generates an optical signal, a first demultiplexer that demultiplexes the optical signal generated by the light source, and one of the optical signals demultiplexed by the first demultiplexer. A first polarization controller that converts the polarization angle and a direction in which the optical signal whose polarization angle has been converted by the first polarization controller is incident on the object to be measured and the optical signal reflected from the object to be measured is acquired. A first reference signal generator for generating a first reference signal of a first frequency, and an optical frequency of the other optical signal demultiplexed by the first demultiplexer based on the first reference signal. From the first optical frequency converter to convert, the second polarization controller to convert the polarization angle of the optical signal whose optical frequency has been converted by the first optical frequency converter, and the object to be measured acquired by the directional coupler The reflected optical signal and the optical signal whose polarization angle is converted by the second polarization controller are combined and output. A first polarization separating photoelectric conversion unit that outputs electrical signals respectively indicating a horizontal polarization component and a vertical polarization component included in the optical signal output from the first multiplexer; A network analyzer that obtains propagation characteristics of the device under test based on the first reference signal generated by the reference signal generation unit and the electrical signal output by the first polarization separation photoelectric conversion unit;

  The first polarization separation photoelectric conversion unit demultiplexes the optical signal output by the first into a polarization polarization demultiplexer that demultiplexes the optical signal of the horizontal polarization component and the optical signal of the vertical polarization component, and a polarization demultiplexer. The first photoelectric converter that converts the waved optical signal of the horizontal polarization component into an electric signal, and the second photoelectric converter that converts the optical signal of the vertical polarization component demultiplexed by the polarization demultiplexer into an electric signal You may have.

  A first frequency divider that divides the electrical signal converted by the first photoelectric conversion unit and supplies it to the network analyzer, and is converted by the second photoelectric conversion unit at the same frequency division ratio as the first frequency divider. A second frequency divider that divides the electrical signal and supplies it to the network analyzer, and a first reference signal generated by the first reference signal generator at the same frequency division ratio as the first frequency divider. You may further provide the 3rd frequency divider supplied to a network analyzer.

  Based on a second demultiplexer that demultiplexes the other optical signal demultiplexed by the first demultiplexer, a second reference signal generator that generates a second reference signal having a second frequency, and a second reference signal A second optical frequency converter for converting the optical frequency of one of the optical signals demultiplexed by the second demultiplexer, and a polarization angle of the optical signal whose optical frequency is converted by the second optical frequency converter. The third polarization controller, the optical signal whose polarization angle is converted by the second polarization controller, and the optical signal whose polarization angle is converted by the third polarization controller are combined and output. A first optical frequency converter that converts the optical frequency of the other optical signal demultiplexed by the second demultiplexer based on the first reference signal, and the first optical frequency converter The optical signal reflected from the object measured by the directional coupler and the optical signal output from the polarization multiplexer The may also be combined.

  The first polarization separation photoelectric conversion unit includes a polarization demultiplexer that demultiplexes the optical signal output from the first multiplexer into a horizontal polarization component optical signal and a vertical polarization component optical signal; A first photoelectric converter that converts the optical signal of the horizontal polarization component demultiplexed by the polarizer into an electric signal, and a second photoelectric converter that converts the optical signal of the vertical polarization component demultiplexed by the polarization demultiplexer into an electric signal. You may have a photoelectric converter.

  A first frequency divider that divides the electrical signal converted by the first photoelectric conversion unit and supplies it to the network analyzer, and is converted by the second photoelectric conversion unit at the same frequency division ratio as the first frequency divider. A second frequency divider that divides the electrical signal and supplies it to the network analyzer, and a first reference signal generated by the first reference signal generator at the same frequency division ratio as the first frequency divider. A third divider supplied to the network analyzer and a fourth divider that divides the second reference signal generated by the second reference signal generator with the same division ratio as the first divider and supplies the second reference signal to the network analyzer. A frequency divider may be further provided.

  A third demultiplexer that demultiplexes the optical signal output from the polarization multiplexer, an optical signal that is incident on the measured object by the directional coupler and passes through the measured object, and is demultiplexed by the third demultiplexer. A second multiplexer that combines and outputs one of the waved optical signals, and an electrical signal that indicates each of the horizontal polarization component and the vertical polarization component included in the optical signal output by the second multiplexer. And a second polarization separation photoelectric conversion unit that outputs the optical signal reflected from the object to be measured acquired by the direction coupler and the other of the signals separated by the third duplexer. And the network analyzer further outputs the second reference signal generated by the second reference signal generation unit and the electric signal output by the second polarization separation photoelectric conversion unit based on the second reference signal generated by the second reference signal generation unit. The propagation characteristics of the measurement object may be obtained.

  The first polarization separation photoelectric conversion unit includes a first polarization demultiplexer that demultiplexes the optical signal output from the first multiplexer into an optical signal with a horizontal polarization component and an optical signal with a vertical polarization component; The first photoelectric converter that converts the optical signal of the horizontal polarization component demultiplexed by the one polarization demultiplexer into an electric signal, and the optical signal of the vertical polarization component demultiplexed by the first polarization demultiplexer And a second polarization separation photoelectric conversion unit that converts the optical signal output from the second multiplexer into an optical signal with a horizontal polarization component and an optical signal with a vertical polarization component. A second polarization demultiplexer, a third photoelectric converter for converting an optical signal of a horizontal polarization component demultiplexed by the second polarization demultiplexer into an electric signal, and a second polarization demultiplexer And a fourth photoelectric converter that converts the optical signal of the vertically polarized component demultiplexed by the above into an electric signal.

  A first frequency divider that divides the electrical signal converted by the first photoelectric conversion unit and supplies it to the network analyzer, and is converted by the second photoelectric conversion unit at the same frequency division ratio as the first frequency divider. A second frequency divider that divides the electrical signal and supplies it to the network analyzer, and a first reference signal generated by the first reference signal generator at the same frequency division ratio as the first frequency divider. A third divider supplied to the network analyzer and a fourth divider that divides the second reference signal generated by the second reference signal generator with the same division ratio as the first divider and supplies the second reference signal to the network analyzer. A frequency divider, a fifth frequency divider that divides the electrical signal converted by the third photoelectric converter at the same frequency division ratio as that of the first frequency divider, and supplies it to the network analyzer; and a first frequency divider Divides the electrical signal converted by the 4th photoelectric converter with the same frequency division ratio It may further include a sixth frequency divider supplied to the network analyzer Te.

  Note that the above summary of the invention does not enumerate all the necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

  According to the optical network analyzer of the present invention, the loss wavelength characteristic, group delay characteristic, chromatic dispersion characteristic, differential group delay characteristic, and polarization mode dispersion characteristic of the object to be measured can be accurately obtained.

  Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the claimed invention, and all combinations of features described in the embodiments are inventions. It is not always essential to the solution.

  FIG. 3 shows an example of the configuration of the optical network analyzer 300 according to the first embodiment of the present invention. The optical network analyzer 300 includes an optical measurement unit 301 and a network analyzer 302. The optical measurement unit 301 includes a tunable light source 304, a demultiplexer 306, a polarization controller 308, an optical frequency converter 310, a polarization controller 312, a reference signal generation unit 314, a multiplexer 316, and a polarization demultiplexer. 318, a photoelectric converter 320, a photoelectric converter 322, a frequency divider 324, a frequency divider 326, and a frequency divider 328. The network analyzer 302 includes a phase comparison amplitude measuring device 348 and an averaging calculation processing unit 350.

  An optical fiber is preferably used as the optical signal transmission medium inside the optical measurement unit 301. The optical frequency converter 310 is, for example, an acousto-optic modulator or an acousto-optic shifter. Further, the multiplexer 316 and the polarization demultiplexer 318 may be replaced with a polarization multiplexer / demultiplexer such as a polarizing prism.

The variable wavelength light source 304 generates a continuous light optical signal having a wavelength λ _i and an optical frequency ω _c . The demultiplexer 306 demultiplexes the optical signal generated by the wavelength variable light source 304. Then, the polarization controller 308 converts the polarization angle of one of the optical signals demultiplexed by the demultiplexer 306 and enters the device under test 10. The reference signal generation unit 314 generates a reference signal having a frequency p and supplies the reference signal to the optical frequency converter 310 and the frequency divider 328. Then, the optical frequency converter 310 converts the optical frequency of the other optical signal demultiplexed by the demultiplexer 306 into ω _c + p based on the reference signal generated by the reference signal generation unit 314. Then, the polarization controller 312 converts the polarization angle of the optical signal whose optical frequency has been converted by the optical frequency converter 310.

  The multiplexer 316 combines the optical signal incident on the device under test 10 by the polarization controller 308 and transmitted through the device under test 10, and the optical signal whose polarization angle has been converted by the polarization controller 312. Output. The polarization demultiplexer 318 demultiplexes the optical signal output from the multiplexer 316 into a horizontal polarization component optical signal and a vertical polarization component optical signal.

  The photoelectric converter 320 converts the optical signal of the horizontal polarization component demultiplexed by the polarization demultiplexer 318 into an electric signal, and supplies it to the signal input port A and the frequency divider 324 of the phase comparison amplitude measuring device 348. To do. Further, the photoelectric converter 322 converts the optical signal of the vertically polarized component demultiplexed by the polarization demultiplexer 318 into an electric signal, the signal input port C of the phase comparison amplitude measuring device 348, and the frequency divider 326. To supply. Note that the polarization demultiplexer 318, the photoelectric converter 320, and the photoelectric converter 322 respectively indicate the horizontal polarization component and the vertical polarization component included in the optical signal output from the multiplexer 316 according to the present invention. It is an example of the polarization separation photoelectric conversion unit that outputs an electric signal.

  The frequency divider 324 divides the electrical signal converted by the photoelectric converter 320 and supplies it to the signal input port B of the phase comparison amplitude measuring device 348. Further, the frequency divider 326 divides the electric signal converted by the photoelectric converter 322 at the same frequency dividing rate as the frequency divider 324 and supplies it to the signal input port D of the phase comparison amplitude measuring device 348. Further, the frequency divider 328 divides the reference signal generated by the reference signal generation unit 314 at the same frequency dividing rate as that of the frequency divider 324 and supplies it to the signal input port E of the phase comparison amplitude measuring device 348. By dividing the electrical signal using the frequency divider 324, the frequency divider 326, and the frequency divider 328, the influence of the drift of the optical measurement unit 401 can be reduced.

  The phase comparison amplitude measuring device 348 is a phase between the electric signal supplied from the photoelectric converter 320 or the frequency divider 324 to the signal input port A or B and the reference signal input from the frequency divider 328 to the signal input port E. And the phase of the electric signal supplied from the photoelectric converter 322 or the frequency divider 326 to the signal input port C or D and the reference signal input from the frequency divider 328 to the signal input port E. And compare amplitudes. Then, the averaging calculation processing unit 350 performs an averaging process on the measurement values measured by the phase comparison amplitude measuring device 348. Then, the network analyzer 302 obtains the loss wavelength characteristic, the group delay characteristic, the chromatic dispersion characteristic, the differential group delay characteristic, and the polarization mode dispersion characteristic of the device under test 10 based on the output data of the averaging calculation processing unit 350. . That is, the network analyzer 302 obtains the propagation characteristics of the DUT 10 based on the reference signal generated by the reference signal generator 314 and the electrical signals output by the photoelectric converter 320 and the photoelectric converter 322.

Next, functions of the optical network analyzer 300 will be described using mathematical expressions. The electric field e ₁ (t) of the optical signal before entering the device under test 10 from the polarization controller 308 is expressed by (Equation 1), and is supplied to the multiplexer 316 from the polarization controller 312. If the electric field e ₂ (t) is expressed by (Equation 2) and the transfer function Y (ω _c ) in the polarization direction of the DUT 10 is expressed by (Equation 3), the polarization demultiplexer 318. field e _d of the optical signal to be supplied to the photoelectric converter 320 from is expressed by equation (4), the output current of the photoelectric converter 320 is expressed by (Equation 5). Further, the relationship of the phase φ _o of the DUT 10 with the optical frequency ω _c of the optical signal and the group delay time τ (ω _c ) have a relationship of (Equation 6).

ネットワークアナライザ３０２は、光電変換器３２０から信号入力ポートＡ又はＢに供給される電気信号と、参照信号発生部３１４から信号入力ポートＥに供給される参照信号との位相及び振幅を比較することによって、位相比較からθ_２−φ_ｏを求めることができ、振幅比較から被測定物１０の損失Ｙ_０を求めることができる。また、波長可変光源３０４によって光信号の光周波数ω_ｃ（波長λ_ｉ）を掃引させながら、上記と同様に位相及び振幅を比較することによって、振幅比較から被測定物１０の位相φ_ｏ及び損失Ｙ_０の波長依存性を求めることができ、位相比較から（数６）の関係に基づいて群遅延特性を求めることができる。

The network analyzer 302 compares the phase and amplitude of the electrical signal supplied from the photoelectric converter 320 to the signal input port A or B and the reference signal supplied from the reference signal generator 314 to the signal input port E. Θ ₂ −φ _o can be obtained from the phase comparison, and the loss Y ₀ of the DUT 10 can be obtained from the amplitude comparison. Further, the phase and amplitude are compared in the same manner as described above while the optical frequency ω _c (wavelength λ _i ) of the optical signal is swept by the wavelength variable light source 304, so that the phase φ _o and the loss of the DUT 10 from the amplitude comparison it is possible to obtain the wavelength dependency of the Y _0, it is possible to determine the group delay characteristics based on a relation from the phase comparator (6).

Furthermore, the network analyzer 302 is configured such that Y _{0 ° _p} (ω _c ), Y _{0 ° _p} (ω _c + Δω), τ _{0 ° _p} (ω _c ), τ _{0 ° _p} (ω _c + Δω), Y _{0 ° _s} ( ω _c ), Y _{0 ° _s} (ω _c + Δω), τ _{0 ° _s} (ω _c ), τ _{0 ° _s} (ω _c + Δω), Y _{90 ° _p} (ω _c ), Y _{90 ° _p} (ω _c + Δω) ), Τ _{90 ° _p} (ω _c ), τ _{90 ° _p} (ω _c + Δω), Y _{90 ° _s} (ω _c ), Y _{90 ° _s} (ω _c + Δω), τ _{90 ° _s} (ω _c ), τ _{Based on 90 ° _s} (ω _c + Δω), the differential group delay characteristic of the DUT 10 can be obtained.

Here, Y _{0 ° _p} (ω _c ), Y _{0 ° _p} (ω _c + Δω), τ _{0 ° _p} (ω _c ), and τ _{0 ° _p} (ω _c + Δω) are generated by the wavelength tunable light source 304. In the case where the optical frequency of the optical signal is ω _c or ω _c + Δω, the polarization angle of the optical signal incident on the device under test 10 from the polarization controller 308 and the multiplexer 316 from the polarization controller 312. Output from the photoelectric converter 320, which is obtained when the polarization angle of the optical signal supplied to the optical signal is controlled to be the same as the polarization angle of the optical signal supplied from the polarization demultiplexer 318 to the photoelectric converter 320. This is the loss and group delay time of the device under test 10 for the horizontal polarization component. Y _{0 ° _s} (ω _c ), Y _{0 ° _s} (ω _c + Δω), τ _{0 ° _s} (ω _c ), and τ _{0 ° _s} (ω _c + Δω) are light generated by the wavelength tunable light source 304. In the case where the optical frequency of the signal is ω _c or ω _c + Δω, the polarization angle of the optical signal incident on the DUT 10 from the polarization controller 308 and the multiplexer 316 from the polarization controller 312. Vertical output from the photoelectric converter 322, which is obtained when the polarization angle of the supplied optical signal is controlled to be the same as the polarization angle of the optical signal supplied from the polarization demultiplexer 318 to the photoelectric converter 320. This is the loss of the device under test 10 and the group delay time for the polarization component.

Y _{90 ° _p} (ω _c ), Y _{90 ° _p} (ω _c + Δω), τ _{90 ° _p} (ω _c ), and τ _{90 ° _p} (ω _c + Δω) are light generated by the wavelength tunable light source 304. In the case where the optical frequency of the signal is ω _c or ω _c + Δω, the polarization angle of the optical signal incident on the DUT 10 from the polarization controller 308 and the multiplexer 316 from the polarization controller 312. The output from the photoelectric converter 320 is obtained when the polarization angle of the supplied optical signal is controlled to be 90 ° different from the polarization angle of the optical signal supplied from the polarization demultiplexer 318 to the photoelectric converter 320. This is the loss of the device under test 10 and the group delay time for the horizontal polarization component. Y _{90 ° _s} (ω _c ), Y _{90 ° _s} (ω _c + Δω), τ _{90 ° _s} (ω _c ), and τ _{90 ° _s} (ω _c + Δω) are light generated by the wavelength tunable light source 304. In this case, the optical frequency of the signal is ω _c or ω _c + Δω, and the loss of the device under test 10 and the group delay time with respect to the vertical polarization component output from the photoelectric converter 322.

  Furthermore, the network analyzer 302 can obtain the polarization mode dispersion characteristic of the DUT 10 using (Equation 7).

  According to the optical network analyzer 300 according to the present embodiment, since the heterodyne detection method is adopted, the wavelength dependence of the polarization characteristic of the DUT 10 having a wide dynamic range can be obtained. Further, since the light intensity modulator is not provided between the wavelength variable light source 304 and the photoelectric converter 320, the transmission characteristic of the DUT 10 can be measured with high accuracy without being affected by the chirp characteristic of the light intensity modulator. can do. Further, since the optical signal incident on the device under test 10 is coherent light, the wavelength characteristics can be measured with high resolution.

  FIG. 4 shows an example of the configuration of an optical network analyzer 400 according to the second embodiment of the present invention. The optical network analyzer 400 includes an optical measurement unit 401 and a network analyzer 402. The optical measurement unit 401 includes a tunable light source 304, a demultiplexer 306, a polarization controller 308, a demultiplexer 410, an optical frequency converter 412, a polarization controller 414, an optical frequency converter 416, and a polarization controller 418. , Reference signal generator 420, reference signal generator 422, polarization multiplexer 424, multiplexer 426, polarization controller 428, polarization demultiplexer 430, photoelectric converter 432, photoelectric converter 434, BPF 436, A BPF 438, a frequency divider 440, a frequency divider 442, a frequency divider 444, and a frequency divider 446 are included. The network analyzer 402 includes a phase comparison amplitude measuring device 448 and an averaging calculation processing unit 350.

  Among the components of the optical network analyzer 400 shown in FIG. 4, the same components as those of the optical network analyzer 300 shown in FIG. 3 include the components of the optical network analyzer 300 shown in FIG. 3. The same reference numerals are given. 3 and 4 have the same functions, the description thereof is partially omitted except for the parts described below.

The polarization controller 308 converts the polarization angle of one of the optical signals demultiplexed by the demultiplexer 306 into ψ (for example, 45 °) and enters the device under test 10. Further, the demultiplexer 410 demultiplexes the other optical signal demultiplexed by the demultiplexer 306. The reference signal generation unit 420 generates a reference signal having the frequency p ₁ and supplies the reference signal to the optical frequency converter 412 and the frequency divider 444. The reference signal generation unit 422 generates a reference signal having the frequency p ₂ and supplies the reference signal to the optical frequency converter 416 and the frequency divider 446.

The optical frequency converter 412 converts the optical frequency of one optical signal demultiplexed by the demultiplexer 410 into ω _c + p ₁ based on the reference signal generated by the reference signal generation unit 420. Then, the polarization controller 414 converts the polarization angle of the optical signal whose optical frequency is converted by the optical frequency converter 412 by ψ-45 ° (for example, 0 °). The optical frequency converter 416 converts the optical frequency of the other optical signal demultiplexed by the demultiplexer 410 into ω _c + p ₂ based on the reference signal generated by the reference signal generation unit 422. Then, the polarization controller 418 converts the polarization angle of the optical signal whose optical frequency is converted by the optical frequency converter 416 by ψ + 45 ° (for example, 90 °). Then, the polarization multiplexer 424 combines the optical signal whose polarization angle has been converted by the polarization controller 414 and the optical signal whose polarization angle has been converted by the polarization controller 418 and outputs it.

  The multiplexer 426 multiplexes the optical signal incident on the device under test 10 by the polarization controller 308 and transmitted through the device under test 10, and the optical signal output from the polarization multiplexer 424. Then, the polarization controller 428 adjusts the polarization angles of the optical frequency converter 412 and the optical frequency converter 416, and the photoelectric converter 432 and the photoelectric converter 434. The polarization demultiplexer 430 demultiplexes the optical signal output from the multiplexer 426 into a horizontal polarization component optical signal and a vertical polarization component optical signal.

  The photoelectric converter 432 converts the optical signal of the horizontal polarization component demultiplexed by the polarization demultiplexer 430 into an electric signal. Further, the photoelectric converter 434 converts the optical signal of the vertical polarization component demultiplexed by the polarization demultiplexer 430 into an electric signal. Note that the polarization demultiplexer 430, the photoelectric converter 432, and the photoelectric converter 434 indicate the horizontal polarization component and the vertical polarization component included in the optical signal output from the multiplexer 426 according to the present invention, respectively. It is an example of the polarization separation photoelectric conversion unit that outputs an electric signal.

The BPF 436 is a band-pass filter having a center frequency of p ₁ , removes the influence of noise and leakage of the electric signal converted by the photoelectric converter 432, the signal input port A of the phase comparison amplitude measuring device 448, and the frequency divider 440 is supplied. The BPF 438 is a band pass filter having a center frequency of p ₂ , removes the influence of noise and leakage of the electric signal converted by the photoelectric converter 434, and removes the signal input port C of the phase comparison amplitude measuring device 448 and the separation signal. This is supplied to the peripheral device 442.

  The frequency divider 440 divides the electric signal converted by the photoelectric converter 432 and transmitted through the BPF 436, and supplies it to the signal input port B of the phase comparison amplitude measuring device 448. The frequency divider 442 divides the electric signal converted by the photoelectric converter 434 and transmitted through the BPF 438 at the same frequency dividing ratio as that of the frequency divider 440 and the signal input port D of the phase comparison amplitude measuring device 448. To supply. Further, the frequency divider 444 divides the reference signal generated by the reference signal generation unit 420 at the same frequency division ratio as that of the frequency divider 440 and supplies the divided signal to the signal input port E of the phase comparison amplitude measuring device 448. Further, the frequency divider 446 divides the reference signal generated by the reference signal generation unit 422 at the same frequency division ratio as that of the frequency divider 440 and supplies it to the signal input port F of the phase comparison amplitude measuring device 448.

  The phase comparison amplitude measuring device 448 calculates the phase and amplitude of the electrical signal supplied from the BPF 436 or the frequency divider 440 to the signal input port A or B and the reference signal input from the frequency divider 444 to the signal input port E. In addition, the phase and amplitude of the electrical signal supplied from the BPF 438 or the frequency divider 442 to the signal input port C or D and the reference signal input from the frequency divider 446 to the signal input port F are compared. Then, the averaging calculation processing unit 350 performs an averaging process on the measurement values measured by the phase comparison amplitude measuring device 448. Then, the network analyzer 402 obtains the loss wavelength characteristic, the group delay characteristic, the chromatic dispersion characteristic, the differential group delay characteristic, and the polarization mode dispersion characteristic of the device under test 10 based on the output data of the averaging calculation processing unit 350. .

  According to the optical network analyzer 400 according to the present embodiment, the duplexer 410, the optical frequency converter 412, the polarization controller 414, the optical frequency converter 416, the polarization controller 418, the reference signal generator 420, the reference signal Since the generator 422 and the polarization multiplexer 424 are provided, the wavelength dependence of the polarization characteristic of the DUT 10 can be obtained by a single wavelength sweep.

  FIG. 5 shows an example of the configuration of an optical network analyzer 500 according to the third embodiment of the present invention. The optical network analyzer 500 includes an optical measurement unit 501 and a network analyzer 402. The optical measurement unit 501 includes a wavelength tunable light source 304, a demultiplexer 306, a polarization controller 508, a demultiplexer 410, an optical frequency converter 412, a polarization controller 414, an optical frequency converter 416, and a polarization controller 418. , Reference signal generator 420, reference signal generator 422, polarization multiplexer 524, multiplexer 526, polarization controller 428, polarization demultiplexer 430, photoelectric converter 432, photoelectric converter 434, BPF 436, A BPF 438, a frequency divider 440, a frequency divider 442, a frequency divider 444, and a frequency divider 446 are included.

  Of the components of the optical network analyzer 500 shown in FIG. 5, the same components as those of the optical network analyzer 300 shown in FIG. 3 or the optical network analyzer 400 shown in FIG. The same reference numerals as those of the optical network analyzer 300 shown in FIG. 4 or the optical network analyzer 400 shown in FIG. Since components having the same reference numerals in FIG. 3 or FIG. 4 and FIG. 5 have the same functions, a part of the description is omitted except for the parts described below.

  The polarization controller 508 converts the polarization angle of one of the optical signals demultiplexed by the demultiplexer 306 into ψ (for example, 45 °) and supplies it to the multiplexer 526. Further, the polarization multiplexer 524 multiplexes the optical signal whose polarization angle is converted by the polarization controller 414 and the optical signal whose polarization angle is converted by the polarization controller 418, and the device under test 10. Is incident on. The multiplexer 526 outputs the optical signal whose polarization angle has been converted by the polarization controller 508 and the optical signal that has been incident on the device under test 10 and transmitted through the device under test 10 by the polarization multiplexer 524. The signals are multiplexed and supplied to the polarization controller 428. As described above, even if the device under test 10 is provided not between the polarization controller 508 and the multiplexer 526 but between the polarization multiplexer 524 and the multiplexer 526, the device under test 10 is measured. The propagation characteristics of the object 10 can be obtained.

  FIG. 6 shows an example of the configuration of an optical network analyzer 600 according to the fourth embodiment of the present invention. The optical network analyzer 600 includes an optical measurement unit 601 and a network analyzer 402. The optical measurement unit 601 includes a tunable light source 304, a demultiplexer 306, a polarization controller 308, a demultiplexer 410, an optical frequency converter 412, a polarization controller 414, an optical frequency converter 416, and a polarization controller 418. , Reference signal generator 420, reference signal generator 422, polarization multiplexer 424, multiplexer 426, photoelectric converter 632, BPF 636, BPF 638, frequency divider 440, frequency divider 442, frequency divider 444, and A frequency divider 446 is included.

  Of the components of the optical network analyzer 600 shown in FIG. 6, the same components as those of the optical network analyzer 300 shown in FIG. 3 or the optical network analyzer 400 shown in FIG. The same reference numerals as those of the optical network analyzer 300 shown in FIG. 4 or the optical network analyzer 400 shown in FIG. Since components having the same reference numerals in FIG. 3 or FIG. 4 and FIG. 5 have the same functions, a part of the description is omitted except for the parts described below.

The photoelectric converter 632 converts the optical signal output from the multiplexer 426 into an electrical signal. The BPF 636 is a band-pass filter having a center frequency of p ₁ and separates an electrical signal indicating a horizontal polarization component included in the optical signal output from the multiplexer 426 from the electrical signal converted by the photoelectric converter 632. Output to the signal input port A of the phase comparison amplitude measuring device 448 and the frequency divider 440. The BPF 638 is a band-pass filter having a center frequency of p ₂ , and an electric signal indicating a vertical polarization component included in the optical signal output from the multiplexer 426 from the electric signal converted by the photoelectric converter 632. The separated signal is output and supplied to the signal input port C and the frequency divider 442 of the phase comparison amplitude measuring device 448. The frequency divider 440 divides the electrical signal output from the BPF 636 and supplies it to the signal input port B of the phase comparison amplitude measuring device 448. Further, the frequency divider 442 divides the electric signal output from the BPF 638 at the same frequency dividing rate as that of the frequency divider 440 and supplies it to the signal input port D of the phase comparison amplitude measuring device 448. In this way, by using only the BPF 636 and the BPF 638 to separate the electrical signal indicating the horizontal polarization component included in the optical signal output from the multiplexer 426, the configuration of the optical measurement unit 601 can be simplified. it can.

  FIG. 7 shows an example of the configuration of an optical network analyzer 700 according to the fifth embodiment of the present invention. The optical network analyzer 700 includes an optical measurement unit 701 and a network analyzer 402. The optical measurement unit 701 includes a wavelength tunable light source 304, a demultiplexer 306, a polarization controller 708, a demultiplexer 410, an optical frequency converter 412, a polarization controller 414, an optical frequency converter 416, and a polarization controller 418. , Reference signal generator 420, reference signal generator 422, polarization multiplexer 724, multiplexer 726, photoelectric converter 632, BPF 636, BPF 638, divider 440, divider 442, divider 444, and A frequency divider 446 is included.

  Among the components of the optical network analyzer 700 shown in FIG. 7, the components of the optical network analyzer 300 shown in FIG. 3, the optical network analyzer 400 shown in FIG. 4, or the optical network analyzer 600 shown in FIG. The same reference numerals as those of the optical network analyzer 300 shown in FIG. 3, the optical network analyzer 400 shown in FIG. 4, or the optical network analyzer 600 shown in FIG. Since components having the same reference numerals in FIGS. 3, 4, or 6 and 7 have the same functions, a part of the description is omitted except for the parts described below.

  The polarization controller 708 converts the polarization angle of one optical signal demultiplexed by the demultiplexer 306 into ψ (for example, 45 °) and supplies the converted signal to the multiplexer 726. Further, the polarization multiplexer 724 multiplexes the optical signal whose polarization angle is converted by the polarization controller 414 and the optical signal whose polarization angle is converted by the polarization controller 418, and the device under test 10. Is incident on. Then, the multiplexer 726 receives the optical signal whose polarization angle has been converted by the polarization controller 708 and the optical signal incident on the device under test 10 and transmitted through the device under test 10 by the polarization multiplexer 724. The signals are multiplexed and supplied to the polarization controller 428. In this way, even if the device under test 10 is not provided between the polarization controller 708 and the multiplexer 726, but between the polarization multiplexer 724 and the multiplexer 726, the device under test 10 is measured. The propagation characteristics of the object 10 can be obtained.

  FIG. 8 shows an example of the configuration of an optical network analyzer 800 according to the sixth embodiment of the present invention. The optical network analyzer 800 includes an optical measurement unit 801 and a network analyzer 302. The optical measurement unit 801 includes a tunable light source 304, a demultiplexer 306, a polarization controller 808, a directional coupler 809, an optical frequency converter 310, a polarization controller 312, a reference signal generation unit 314, and a multiplexer 816. A polarization demultiplexer 318, a photoelectric converter 320, a photoelectric converter 322, a frequency divider 324, a frequency divider 326, and a frequency divider 328.

  Of the constituent elements of the optical network analyzer 800 shown in FIG. 8, the same constituent elements as those of the optical network analyzer 300 shown in FIG. 3 include the constituent elements of the optical network analyzer 300 shown in FIG. The same reference numerals are given. Since components having the same reference numerals in FIGS. 3 and 8 have the same functions, a part of the description is omitted except for the parts described below.

  The polarization controller 808 converts the polarization angle of one optical signal demultiplexed by the demultiplexer 306. Then, the directional coupler 809 makes the optical signal whose polarization angle is converted by the polarization controller 808 incident on the device under test 10 and acquires the optical signal reflected from the device under test 10. Then, the multiplexer 816 combines the optical signal reflected from the DUT 10 acquired by the directional coupler 809 and the optical signal whose polarization angle has been converted by the polarization controller 312 to be polarized. Output to the duplexer 318. The optical network analyzer 300 shown in FIG. 3 can measure the transmitted light of the device under test 10, but the optical network analyzer 800 shown in FIG. 8 uses the directional coupler 809 to measure the device under test 10. The reflected light of the object to be measured 10 can be measured by acquiring the optical signal reflected from the object.

  FIG. 9 shows an example of the configuration of an optical network analyzer 900 according to the seventh embodiment of the present invention. The optical network analyzer 900 includes an optical measurement unit 901 and a network analyzer 402. The optical measuring unit 901 includes a tunable light source 304, a demultiplexer 306, a polarization controller 808, a directional coupler 809, a demultiplexer 410, an optical frequency converter 412, a polarization controller 414, and an optical frequency converter 416. , Polarization controller 418, reference signal generator 420, reference signal generator 422, polarization multiplexer 424, multiplexer 926, polarization demultiplexer 430, photoelectric converter 432, photoelectric converter 434, BPF 436, A BPF 438, a frequency divider 440, a frequency divider 442, a frequency divider 444, and a frequency divider 446 are included.

  Of the components of the optical network analyzer 900 shown in FIG. 9, the components of the optical network analyzer 300 shown in FIG. 3, the optical network analyzer 400 shown in FIG. 4, or the optical network analyzer 800 shown in FIG. The same reference numerals as those of the optical network analyzer 300 shown in FIG. 3, the optical network analyzer 400 shown in FIG. 4, or the optical network analyzer 800 shown in FIG. Since components having the same reference numerals in FIG. 3, FIG. 4, or FIG. 8 and FIG. 9 have the same functions, a part of the description is omitted except for the parts described below.

  The multiplexer 926 multiplexes the optical signal reflected from the DUT 10 acquired by the directional coupler 809 and the optical signal output from the polarization multiplexer 424 and outputs the resultant signal to the polarization controller 428. To do. The optical network analyzer 400 shown in FIG. 4 can measure the transmitted light of the device under test 10, but the optical network analyzer 900 shown in FIG. 9 uses the directional coupler 809 to measure the device under test 10. The reflected light of the object to be measured 10 can be measured by acquiring the optical signal reflected from the object.

  FIG. 10 shows an example of the configuration of an optical network analyzer 1000 according to the eighth embodiment of the present invention. The optical network analyzer 1000 includes an optical measurement unit 1001 and a network analyzer 1002. The optical measuring unit 1001 includes a tunable light source 304, a demultiplexer 306, a polarization controller 808, a directional coupler 809, a demultiplexer 410, an optical frequency converter 412, a polarization controller 414, and an optical frequency converter 416. , Polarization controller 418, reference signal generator 420, reference signal generator 422, polarization multiplexer 424, demultiplexer 1006, multiplexer 1008, polarization demultiplexer 1012, photoelectric converter 1014, photoelectric converter 1016, divider 1024, divider 1026, multiplexer 1010, polarization divider 1018, photoelectric converter 1020, photoelectric converter 1022, divider 1028, divider 1030, divider 1036, and A frequency divider 1038. The network analyzer 1002 includes a phase comparison amplitude measuring device 1032 and an averaging calculation processing unit 350.

  Of the components of the optical network analyzer 1000 shown in FIG. 10, the optical network analyzer 300 shown in FIG. 3, the optical network analyzer 400 shown in FIG. 4, the optical network analyzer 800 shown in FIG. The same components as those of the optical network analyzer 900 shown in FIG. 3 include the optical network analyzer 300 shown in FIG. 3, the optical network analyzer 400 shown in FIG. 4, the optical network analyzer 800 shown in FIG. The same reference numerals as those in the optical network analyzer 900 shown in FIG. 3, 4, 8, 9, and 10 have the same functions, and therefore, a part of the description is omitted except for the parts described below.

  A demultiplexer 1006 demultiplexes the optical signal output from the polarization multiplexer 424. The multiplexer 1008 combines the optical signal that has been incident on the device under test 10 by the directional coupler 809 and passed through the device under test 10, and one optical signal that has been demultiplexed by the duplexer 1006. And output. Further, the multiplexer 1010 combines the optical signal reflected from the device under test 10 acquired by the directional coupler 809 and the other optical signal demultiplexed by the demultiplexer 1006 and outputs the combined signal.

  The polarization demultiplexer 1012 demultiplexes the optical signal output from the multiplexer 1008 into an optical signal with a horizontal polarization component and an optical signal with a vertical polarization component. Then, the photoelectric converter 1014 converts the optical signal of the horizontal polarization component demultiplexed by the polarization demultiplexer 1012 into an electric signal, and sends it to the signal input port A and the frequency divider 1024 of the phase comparison amplitude measuring device 1032. Supply. In addition, the photoelectric converter 1016 converts the optical signal of the vertical polarization component demultiplexed by the polarization demultiplexer 1012 into an electric signal, and supplies it to the signal input port C and the frequency divider 1026 of the phase comparison amplitude measuring device 1032. Supply.

  The polarization demultiplexer 1018 demultiplexes the optical signal output from the multiplexer 1010 into a horizontal polarization component optical signal and a vertical polarization component optical signal. Then, the photoelectric converter 1020 converts the optical signal of the horizontal polarization component demultiplexed by the polarization demultiplexer 1018 into an electric signal, and sends it to the signal input port E and the frequency divider 1028 of the phase comparison amplitude measuring device 1032. Supply. In addition, the photoelectric converter 1022 converts the optical signal of the vertical polarization component demultiplexed by the polarization demultiplexer 1018 into an electric signal, and supplies it to the signal input port G and the frequency divider 1030 of the phase comparison amplitude measuring device 1032. Supply.

  Note that the polarization demultiplexer 1012, the photoelectric converter 1014, and the photoelectric converter 1016 respectively indicate the horizontal polarization component and the vertical polarization component included in the optical signal output from the multiplexer 1008 according to the present invention. It is an example of the 1st polarization separation photoelectric conversion part which outputs an electric signal. Further, the polarization demultiplexer 1018, the photoelectric converter 1020, and the photoelectric converter 1022 respectively indicate a horizontal polarization component and a vertical polarization component included in the optical signal output from the multiplexer 1010 according to the present invention. It is an example of the 2nd polarization separation photoelectric conversion part which outputs an electric signal.

  The frequency divider 1024 divides the electric signal converted by the photoelectric converter 1014 and supplies it to the signal input port B of the phase comparison amplitude measuring device 1032. Further, the frequency divider 1026 divides the electric signal converted by the photoelectric converter 1016 at the same frequency dividing rate as that of the frequency divider 1024 and supplies it to the signal input port D of the phase comparison amplitude measuring device 1032. Further, the frequency divider 1028 divides the electric signal converted by the photoelectric converter 1020 at the same frequency dividing rate as that of the frequency divider 1024 and supplies it to the signal input port F of the phase comparison amplitude measuring device 1032. Further, the frequency divider 1030 divides the electric signal converted by the photoelectric converter 1022 at the same frequency dividing rate as that of the frequency divider 1024 and supplies it to the signal input port H of the phase comparison amplitude measuring device 1032. Further, the frequency divider 1036 divides the reference signal generated by the reference signal generation unit 420 at the same frequency division ratio as that of the frequency divider 1024 and supplies it to the signal input port I of the phase comparison amplitude measuring device 1032. Further, the frequency divider 1038 divides the reference signal generated by the reference signal generation unit 422 at the same frequency division ratio as that of the frequency divider 1024 and supplies it to the signal input port J of the phase comparison amplitude measuring device 1032.

  The phase comparison amplitude measuring device 1032 is supplied from the photoelectric converter 1014 or the frequency divider 1024 to the signal input port A or B, or supplied from the photoelectric converter 1020 or the frequency divider 1028 to the signal input port E or F. The phase and amplitude of the electrical signal thus obtained and the reference signal input from the frequency divider 1036 to the signal input port I are compared. In addition, an electric signal supplied from the photoelectric converter 1016 or the frequency divider 1026 to the signal input port C or D, or an electric signal supplied from the photoelectric converter 1022 or the frequency divider 1030 to the signal input port G or H, The phase and amplitude of the reference signal input to the signal input port J from the frequency divider 1038 are compared.

  The optical network analyzer 400 shown in FIG. 4 can measure the transmitted light of the device under test 10, and the optical network analyzer 900 shown in FIG. 9 can measure the reflected light of the device under test 10. However, the optical network analyzer 1000 shown in FIG. 10 can simultaneously measure the transmitted light and the reflected light of the DUT 10.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. Various modifications or improvements can be added to the above embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

It is a block diagram of the optical network analyzer 100 which concerns on a prior art. It is a block diagram of the optical network analyzer 200 based on a prior art. 1 is a configuration diagram of an optical network analyzer 300 according to a first embodiment. FIG. It is a block diagram of the optical network analyzer 400 which concerns on 2nd Embodiment. It is a block diagram of the optical network analyzer 500 which concerns on 3rd Embodiment. It is a block diagram of the optical network analyzer 600 which concerns on 4th Embodiment. It is a block diagram of the optical network analyzer 700 which concerns on 5th Embodiment. It is a block diagram of the optical network analyzer 800 which concerns on 6th Embodiment. It is a block diagram of the optical network analyzer 900 which concerns on 7th Embodiment. It is a block diagram of the optical network analyzer 1000 which concerns on 8th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Device under test 300 Optical network analyzer 301 Optical measurement part 302 Network analyzer 304 Variable wavelength light source 306 Demultiplexer 308 Polarization controller 310 Optical frequency converter 312 Polarization controller 314 Reference signal generation part 316 Multiplexer 318 Polarization Demultiplexer 320 Photoelectric converter 322 Photoelectric converter 324 Frequency divider 326 Frequency divider 328 Frequency divider 348 Phase comparison amplitude measuring device 350 Averaging operation processing unit 400 Optical network analyzer 401 Optical measurement unit 402 Network analyzer 410 412 Optical frequency converter 414 Polarization controller 416 Optical frequency converter 418 Polarization controller 420 Reference signal generator 422 Reference signal generator 424 Polarization multiplexer 426 Multiplexer 428 Polarization controller 430 Polarization demultiplexing 432 Photoelectric converter 434 Photoelectric converter 436 BPF
438 BPF
440 Divider 442 Divider 444 Divider 446 Divider 448 Phase comparison amplitude measuring device 500 Optical network analyzer 501 Optical measuring unit 508 Polarization controller 524 Polarization multiplexer 526 Multiplexer 600 Optical network analyzer 601 Optical measurement unit 632 photoelectric converter 636 BPF
638 BPF
700 Optical Network Analyzer 701 Optical Measurement Unit 708 Polarization Controller 724 Polarization Combiner 726 Multiplexer 800 Optical Network Analyzer 801 Optical Measurement Unit 808 Polarization Controller 809 Directional Coupler 816 Multiplexer 900 Optical Network Analyzer 901 Optical measurement unit 926 multiplexer 1000 optical network analyzer 1001 optical measurement unit 1002 network analyzer 1006 duplexer 1008 multiplexer 1010 multiplexer 1012 polarization splitter 1014 photoelectric converter 1016 photoelectric converter 1018 polarization splitter 1020 Photoelectric converter 1022 Photoelectric converter 1024 Frequency divider 1026 Frequency divider 1028 Frequency divider 1030 Frequency divider 1032 Phase comparison amplitude measuring instrument 1036 Frequency divider 1038 Frequency divider

Claims (23)

A light source that generates an optical signal;
A first duplexer for demultiplexing an optical signal generated by the light source;
A first polarization controller that converts the polarization angle of one of the optical signals demultiplexed by the first demultiplexer and enters the device under test;
A first reference signal generator for generating a first reference signal of a first frequency;
A first optical frequency converter that converts the optical frequency of the other optical signal demultiplexed by the first demultiplexer based on the first reference signal;
A second polarization controller for converting the polarization angle of the optical signal whose optical frequency has been converted by the first optical frequency converter;
An optical signal that has been incident on the object to be measured by the first polarization controller and transmitted through the object to be measured and an optical signal whose polarization angle has been converted by the second polarization controller are combined and output. A combiner,
A polarization-separating photoelectric conversion unit that outputs electrical signals respectively indicating a horizontal polarization component and a vertical polarization component included in the optical signal output by the multiplexer;
An optical network analyzer comprising: a network analyzer for obtaining a propagation characteristic of the device under test based on the first reference signal generated by the first reference signal generation unit and the electric signal output by the polarization separation photoelectric conversion unit . The polarization separation photoelectric conversion unit,
A polarization demultiplexer that demultiplexes the optical signal output from the multiplexer into an optical signal of a horizontal polarization component and an optical signal of a vertical polarization component;
A first photoelectric converter that converts an optical signal of a horizontally polarized wave component demultiplexed by the polarization demultiplexer into an electric signal;
The optical network analyzer according to claim 1, further comprising: a second photoelectric converter that converts an optical signal having a vertically polarized wave component demultiplexed by the polarization demultiplexer into an electric signal. A first frequency divider that divides the electrical signal converted by the first photoelectric conversion unit and supplies the frequency to the network analyzer;
A second frequency divider that divides the electrical signal converted by the second photoelectric conversion unit and supplies it to the network analyzer at the same frequency division ratio as the first frequency divider;
And a third frequency divider that divides the first reference signal generated by the first reference signal generation unit and supplies the first reference signal to the network analyzer at the same frequency division ratio as the first frequency divider. Item 3. The optical network analyzer according to Item 2. A second demultiplexer for demultiplexing the other optical signal demultiplexed by the first demultiplexer;
A second reference signal generator for generating a second reference signal of a second frequency;
A second optical frequency converter that converts the optical frequency of one of the optical signals demultiplexed by the second demultiplexer based on the second reference signal;
A third polarization controller for converting the polarization angle of the optical signal whose optical frequency has been converted by the second optical frequency converter;
A polarization multiplexer that multiplexes and outputs the optical signal whose polarization angle is converted by the second polarization controller and the optical signal whose polarization angle is converted by the third polarization controller; Prepared,
The first optical frequency converter converts the optical frequency of the other optical signal demultiplexed by the second demultiplexer based on the first reference signal;
The multiplexer combines the optical signal that has been incident on the object to be measured by the first polarization controller and transmitted through the object to be measured, and the optical signal that has been output by the polarization multiplexer. Item 5. The optical network analyzer according to Item 1. The polarization separation photoelectric conversion unit,
A polarization demultiplexer that demultiplexes the optical signal output from the multiplexer into an optical signal of a horizontal polarization component and an optical signal of a vertical polarization component;
A first photoelectric converter that converts an optical signal of a horizontally polarized wave component demultiplexed by the polarization demultiplexer into an electric signal;
5. The optical network analyzer according to claim 4, further comprising: a second photoelectric converter that converts an optical signal of a vertically polarized component demultiplexed by the polarization demultiplexer into an electric signal. A first frequency divider that divides the electrical signal converted by the first photoelectric conversion unit and supplies the frequency to the network analyzer;
A second frequency divider that divides the electrical signal converted by the second photoelectric conversion unit and supplies it to the network analyzer at the same frequency division ratio as the first frequency divider;
A third frequency divider that divides the first reference signal generated by the first reference signal generator and supplies it to the network analyzer at the same frequency division ratio as the first frequency divider;
And a fourth frequency divider that divides the second reference signal generated by the second reference signal generation unit and supplies it to the network analyzer at the same frequency division ratio as the first frequency divider. Item 6. The optical network analyzer according to Item 5. A photoelectric converter that converts the optical signal output by the multiplexer into an electrical signal;
A first band transmission filter that separates and outputs an electrical signal indicating a horizontal polarization component included in the optical signal output from the multiplexer from the electrical signal converted by the photoelectric converter;
5. A second band pass filter for separating and outputting an electrical signal indicating a vertical polarization component included in an optical signal output from the multiplexer from an electrical signal converted by the photoelectric converter. Optical network analyzer described in 1. A first frequency divider that divides the electrical signal output by the first band pass filter and supplies it to the network analyzer;
A second frequency divider that divides the electrical signal output by the second band pass filter and supplies it to the network analyzer at the same frequency division ratio as the first frequency divider;
A third frequency divider that divides the first reference signal generated by the first reference signal generator and supplies it to the network analyzer at the same frequency division ratio as the first frequency divider;
And a fourth frequency divider that divides the second reference signal generated by the second reference signal generation unit and supplies it to the network analyzer at the same frequency division ratio as the first frequency divider. Item 8. The optical network analyzer according to Item 7. A light source that generates an optical signal;
A first duplexer for demultiplexing an optical signal generated by the light source;
A first polarization controller that converts a polarization angle of one of the optical signals demultiplexed by the first demultiplexer;
A first reference signal generator for generating a first reference signal of a first frequency;
A first optical frequency converter that converts the optical frequency of the other optical signal demultiplexed by the first demultiplexer based on the first reference signal;
A second polarization controller that converts the polarization angle of the optical signal whose optical frequency has been converted by the first optical frequency converter and enters the device under test; and
Combines an optical signal whose polarization angle has been converted by the first polarization controller and an optical signal that has been incident on the object to be measured and transmitted through the object to be measured by the second polarization controller. And
A polarization separation photoelectric conversion unit that outputs an electrical signal indicating a horizontal polarization component and a vertical polarization component included in the optical signal output by the multiplexer; and
An optical network analyzer comprising: a network analyzer for obtaining a propagation characteristic of the device under test based on the first reference signal generated by the first reference signal generation unit and the electric signal output by the polarization separation photoelectric conversion unit . A second demultiplexer for demultiplexing the other optical signal demultiplexed by the first demultiplexer;
A second reference signal generator for generating a second reference signal of a second frequency;
A second optical frequency converter that converts the optical frequency of one of the optical signals demultiplexed by the second demultiplexer based on the second reference signal;
A third polarization controller for converting the polarization angle of the optical signal whose optical frequency has been converted by the second optical frequency converter;
The polarization signal whose polarization angle is converted by the second polarization controller and the optical signal whose polarization angle is converted by the third polarization controller are combined and incident on the object to be measured. Further equipped with a waver,
The first optical frequency converter converts the optical frequency of the other optical signal demultiplexed by the second demultiplexer based on the first reference signal;
The multiplexer includes an optical signal whose polarization angle is converted by the first polarization controller, and an optical signal that is incident on the object to be measured and transmitted through the object to be measured by the polarization multiplexer. The optical network analyzer according to claim 9 for multiplexing. The polarization separation photoelectric conversion unit,
A polarization demultiplexer that demultiplexes the optical signal output from the multiplexer into an optical signal of a horizontal polarization component and an optical signal of a vertical polarization component;
A first photoelectric converter that converts an optical signal of a horizontally polarized wave component demultiplexed by the polarization demultiplexer into an electric signal;
The optical network analyzer according to claim 10, further comprising: a second photoelectric converter that converts an optical signal of a vertically polarized component demultiplexed by the polarization demultiplexer into an electric signal. A first frequency divider that divides the electrical signal converted by the first photoelectric conversion unit and supplies the frequency to the network analyzer;
A second frequency divider that divides the electrical signal converted by the second photoelectric conversion unit and supplies it to the network analyzer at the same frequency division ratio as the first frequency divider;
A third frequency divider that divides the first reference signal generated by the first reference signal generator at the same frequency division ratio as that of the first frequency divider and supplies the first reference signal to the network analyzer; 12. The fourth divider according to claim 11, further comprising a fourth divider that divides the second reference signal generated by the second reference signal generator and supplies the divided signal to the network analyzer at the same division ratio as that of the divider. Optical network analyzer. A photoelectric converter that converts the optical signal output by the multiplexer into an electrical signal;
A first band transmission filter that separates and outputs an electrical signal indicating a horizontal polarization component included in the optical signal output from the multiplexer from the electrical signal converted by the photoelectric converter;
11. A second band-pass filter for separating and outputting an electrical signal indicating a vertical polarization component included in an optical signal output from the multiplexer from an electrical signal converted by the photoelectric converter. Optical network analyzer described in 1. A first frequency divider that divides the electrical signal output by the first band pass filter and supplies it to the network analyzer;
A second frequency divider that divides the electrical signal output by the second band pass filter and supplies it to the network analyzer at the same frequency division ratio as the first frequency divider;
A third frequency divider that divides the first reference signal generated by the first reference signal generator and supplies it to the network analyzer at the same frequency division ratio as the first frequency divider;
And a fourth frequency divider that divides the second reference signal generated by the second reference signal generation unit and supplies it to the network analyzer at the same frequency division ratio as the first frequency divider. Item 14. An optical network analyzer according to Item 13. A light source that generates an optical signal;
A first duplexer for demultiplexing an optical signal generated by the light source;
A first polarization controller that converts a polarization angle of one of the optical signals demultiplexed by the first demultiplexer;
A directional coupler that enters an optical signal whose polarization angle has been converted by the first polarization controller, and acquires an optical signal reflected from the measured object;
A first reference signal generator for generating a first reference signal of a first frequency;
A first optical frequency converter that converts the optical frequency of the other optical signal demultiplexed by the first demultiplexer based on the first reference signal;
A second polarization controller for converting the polarization angle of the optical signal whose optical frequency has been converted by the first optical frequency converter;
A first multiplexer that combines and outputs the optical signal reflected from the object to be measured acquired by the directional coupler and the optical signal whose polarization angle has been converted by the second polarization controller;
A first polarization separation photoelectric conversion unit that outputs an electrical signal indicating a horizontal polarization component and a vertical polarization component included in the optical signal output by the first multiplexer;
A network analyzer that obtains propagation characteristics of the device under test based on the first reference signal generated by the first reference signal generation unit and the electrical signal output by the first polarization separation photoelectric conversion unit; Optical network analyzer provided. The first polarization separation photoelectric conversion unit includes:
A polarization demultiplexer for demultiplexing the optical signal output by the first into an optical signal of a horizontal polarization component and an optical signal of a vertical polarization component;
A first photoelectric converter that converts an optical signal of a horizontally polarized wave component demultiplexed by the polarization demultiplexer into an electric signal;
The optical network analyzer according to claim 15, further comprising: a second photoelectric converter that converts an optical signal of a vertical polarization component demultiplexed by the polarization demultiplexer into an electric signal. A first frequency divider that divides the electrical signal converted by the first photoelectric conversion unit and supplies the frequency to the network analyzer;
A second frequency divider that divides the electrical signal converted by the second photoelectric conversion unit and supplies it to the network analyzer at the same frequency division ratio as the first frequency divider;
And a third frequency divider that divides the first reference signal generated by the first reference signal generation unit and supplies the first reference signal to the network analyzer at the same frequency division ratio as the first frequency divider. Item 17. The optical network analyzer according to Item 16. A second demultiplexer for demultiplexing the other optical signal demultiplexed by the first demultiplexer;
A second reference signal generator for generating a second reference signal of a second frequency;
A second optical frequency converter that converts the optical frequency of one of the optical signals demultiplexed by the second demultiplexer based on the second reference signal;
A third polarization controller for converting the polarization angle of the optical signal whose optical frequency has been converted by the second optical frequency converter;
A polarization multiplexer that multiplexes and outputs the optical signal whose polarization angle is converted by the second polarization controller and the optical signal whose polarization angle is converted by the third polarization controller; Prepared,
The first optical frequency converter converts the optical frequency of the other optical signal demultiplexed by the second demultiplexer based on the first reference signal;
The light according to claim 15, wherein the first multiplexer multiplexes an optical signal reflected from the device under test acquired by the directional coupler and an optical signal output from the polarization multiplexer. Network analyzer. The first polarization separation photoelectric conversion unit includes:
A polarization demultiplexer for demultiplexing the optical signal output from the first multiplexer into an optical signal of a horizontal polarization component and an optical signal of a vertical polarization component;
A first photoelectric converter that converts an optical signal of a horizontally polarized wave component demultiplexed by the polarization demultiplexer into an electric signal;
The optical network analyzer according to claim 18, further comprising: a second photoelectric converter that converts an optical signal of a vertically polarized component demultiplexed by the polarization demultiplexer into an electric signal. A first frequency divider that divides the electrical signal converted by the first photoelectric conversion unit and supplies the frequency to the network analyzer;
A second frequency divider that divides the electrical signal converted by the second photoelectric conversion unit and supplies it to the network analyzer at the same frequency division ratio as the first frequency divider;
A third frequency divider that divides the first reference signal generated by the first reference signal generator and supplies it to the network analyzer at the same frequency division ratio as the first frequency divider;
And a fourth frequency divider that divides the second reference signal generated by the second reference signal generation unit and supplies it to the network analyzer at the same frequency division ratio as the first frequency divider. Item 20. An optical network analyzer according to Item 19. A third demultiplexer for demultiplexing the optical signal output from the polarization multiplexer;
A second optical signal that is incident on the object to be measured by the directional coupler and passes through the object to be measured and one optical signal that has been demultiplexed by the third demultiplexer are output. A multiplexer,
A second polarization separation photoelectric conversion unit that outputs an electrical signal indicating each of a horizontal polarization component and a vertical polarization component included in the optical signal output by the second multiplexer;
The first multiplexer combines and outputs the optical signal reflected from the device under test acquired by the directional coupler and the other optical signal demultiplexed by the third demultiplexer. ,
The network analyzer further determines a propagation characteristic of the device under test based on the second reference signal generated by the second reference signal generation unit and the electrical signal output by the second polarization separation photoelectric conversion unit. The optical network analyzer according to claim 18. The first polarization separation photoelectric conversion unit includes:
A first polarization demultiplexer for demultiplexing an optical signal output from the first multiplexer into an optical signal of a horizontal polarization component and an optical signal of a vertical polarization component;
A first photoelectric converter that converts an optical signal of a horizontal polarization component demultiplexed by the first polarization demultiplexer into an electric signal;
A second photoelectric converter that converts an optical signal of a vertically polarized component demultiplexed by the first polarization demultiplexer into an electric signal;
The second polarization separation photoelectric conversion unit is
A second polarization demultiplexer for demultiplexing the optical signal output by the second multiplexer into an optical signal of a horizontal polarization component and an optical signal of a vertical polarization component;
A third photoelectric converter that converts an optical signal of a horizontally polarized wave component demultiplexed by the second polarization demultiplexer into an electric signal;
The optical network analyzer according to claim 21, further comprising: a fourth photoelectric converter that converts an optical signal having a vertical polarization component demultiplexed by the second polarization demultiplexer into an electric signal. A first frequency divider that divides the electrical signal converted by the first photoelectric conversion unit and supplies the frequency to the network analyzer;
A second frequency divider that divides the electrical signal converted by the second photoelectric conversion unit and supplies the same to the network analyzer at the same frequency division ratio as the first frequency divider;
A third frequency divider that divides the first reference signal generated by the first reference signal generator and supplies it to the network analyzer at the same frequency division ratio as the first frequency divider;
A fourth frequency divider that divides the second reference signal generated by the second reference signal generation unit and supplies it to the network analyzer at the same frequency division ratio as the first frequency divider;
A fifth frequency divider that divides the electrical signal converted by the third photoelectric conversion unit and supplies it to the network analyzer at the same frequency division ratio as the first frequency divider;
23. The sixth divider according to claim 22, further comprising a sixth divider that divides the electric signal converted by the fourth photoelectric conversion unit and supplies the divided signal to the network analyzer at the same division ratio as the first divider. The optical network analyzer described.

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