JP2004093407A - Apparatus and method for identifying coated optical fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and a method for identifying coated optical fibers capable of carrying out coated optical fiber identification test without reducing the quality of communications. <P>SOLUTION: The apparatus for identifying coated optical fibers is provided with both a location changing part 19 for changing the location of a coated optical fiber 4a of an optical fiber and a measuring part 17 for detecting variations in a specific polarized component of light caused by changes in the location of the coated optical fiber 4a of the optical fiber and measuring its amount of variation. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical fiber control test apparatus and an optical fiber control test for performing an optical fiber control test on an optical fiber optical fiber by injecting light (hereinafter, referred to as test light) into the optical fiber optical fiber. About the method.
[0002]
[Prior art]
In constructing an optical communication network using an optical fiber, performing maintenance and inspection, etc., it is necessary to perform a core-wire comparison test to identify the core of the optical fiber to be worked.
[0003]
In performing the above-described core-wire contrast test, a core-wire contrast test apparatus 100a as illustrated in FIG. 8 is used.
In the figure, the intra-station device 105 and the terminal-side device 108 are connected via a branch module 106 and an optical fiber 107a, and the communication light 109 is transmitted by the optical fiber 107a.
[0004]
The optical fiber contrast test apparatus 100a is for performing an optical fiber contrast test on the optical fiber 107a, that is, the working line, and includes a test light transmitting unit 101, a test light receiving unit 102, a reflecting unit 103, and a core bending. It has a part 104.
[0005]
The test light transmitting unit 101 is connected to the branch module 106, and makes the test light 110 having a different wavelength from the communication light 109 enter the core wire 107 a via the branch module 106. The test light 110 is formed by 270 Hz modulated light.
[0006]
The core wire bending portion 104 bends a part of the core wire 107a. Thereby, a part (leakage light) of the test light 110 that has propagated inside the core wire 107a leaks.
[0007]
The test light receiving unit 102 detects the above-mentioned leaked light. Thereby, those skilled in the art can confirm that the cord 107a is the cord to be worked.
[0008]
The reflection unit 103 includes a filter member that reflects only the test light 110 and transmits the communication light 109.
[0009]
The core control test apparatus 100a in FIG. 8 is for performing a core control test on the working line, but the core control test apparatus 100b illustrated in FIG. This is for performing a core wire comparison test on a core wire (core wire 107a in this figure) which is not transmitting the test light, and the test light transmitting unit 101 and the test light beam as in the core wire comparison test device 100a of FIG. It has a receiving unit 102 and a cord bending unit 104.
[0010]
The test light transmitter 101 causes the test light 110 to be incident on the core wire 107a via the branch module 106.
[0011]
The core wire bending portion 104 bends a part of the core wire 107a. Thereby, a part (leakage light) of the test light 110 that has propagated inside the core wire 107a leaks.
[0012]
The test light receiving unit 102 detects the above-mentioned leaked light. Thereby, those skilled in the art can confirm that the cord 107a is the cord to be worked.
[0013]
The wavelength of the test light 110 is set to be longer than the wavelength of general communication light in consideration of the case where the core wire 107a transmits the test light for some reason.
[0014]
As general communication light, light having a wavelength of 1.31 μm, 1.55 μm, or 1.625 μm is often used. These three types of light were made to enter the core wire, the light was leaked by the above-mentioned core type contrast test apparatus, and the intensity loss of each of the three types of light was measured. FIG. 10 shows the result.
[0015]
The intensity loss when light having a wavelength of 1.31 μm is incident is smaller than that when the other two types of light are incident, and is at most 0.1 dB. With such a small loss, even if the core line control test is performed on the working line, the service quality does not deteriorate.
[0016]
[Problems to be solved by the invention]
However, there is a problem to be solved as described below in the above-described core-wire contrast test apparatus.
As described above, the core-line contrast test apparatus may also perform tests on the working line, and with the recent development of the optical unbundling service, the wavelength management of the communication light propagating through the core of the optical fiber has become difficult. It becomes difficult. That is, even if the carrier uses communication light having a long wavelength, it cannot be regulated, and the communication light wavelength may be close to the test light wavelength. Also, even if the communication optical wavelength used by the carrier can be managed, the diversification of optical communication services in the future, the introduction of wavelength multiplexing technology along with the high-speed broadband of the network, the communication wavelength can be made longer. Very high.
[0017]
Further, as shown in FIG. 10, the light having a wavelength of 1.55 μm causes an excess loss of 2.5 dB at the maximum, and the light having a wavelength of 1.625 μm causes an excess loss of 5.0 dB at a maximum. That is, if the communication wavelength is increased from 1.51 μm or 1.625 μm to the conventional wavelength of 1.31 μm, it is expected that the communication quality will be degraded.
[0018]
In view of such circumstances, an object of the present invention is to provide a core-line control test device and a core-line control test method that can perform a core-line control test without deteriorating communication quality.
[0019]
[Means for Solving the Problems]
The present invention according to claim 1 is a core contrast test apparatus for performing a core contrast test on a core by causing light to enter a core of an optical fiber and detecting the light. The gist of the present invention is to include a position changing means for changing the position and a fluctuation detecting means for detecting a change in a specific polarization component of light caused by a change in the position of the core wire.
[0020]
According to the first aspect of the present invention, only a change in a specific polarization component of light is detected. This variation does not affect the intensity of long-wavelength communication light propagating in the core wire because it occurs only by slightly changing the position without bending the core wire. Therefore, it is possible to perform a core line comparison test on the working line without deteriorating the communication quality.
[0021]
According to a second aspect of the present invention, in the first aspect of the present invention, the fluctuation detecting means is located on the incident end side of the light of the core wire, and the light output of the core wire is detected on the emission end side of the light of the core wire. The gist of the present invention is to detect a fluctuation amount of a specific polarization component reflected toward the incident end.
[0022]
According to a third aspect of the present invention, in the first aspect, the fluctuation detecting means is located on the light emitting end side of the cord.
[0023]
The gist of the present invention described in claim 4 is that, in the invention of claims 1 to 3, a specific polarization component incidence unit that causes only a specific polarization component to be incident on the core is provided.
[0024]
According to a fifth aspect of the present invention, there is provided an optical fiber contrast test method for performing an optical fiber contrast test on an optical fiber by irradiating light to the optical fiber of the optical fiber and detecting the light. The gist of the present invention is to change the position and to detect a change in a specific polarization component of light caused by a change in the position of the cord.
[0025]
According to the fifth aspect of the present invention, only a change in a specific polarization component of light is detected. This variation does not affect the intensity of long-wavelength communication light propagating in the core wire because it occurs only by slightly changing the position without bending the core wire. Therefore, it is possible to perform a core line comparison test on the working line without deteriorating the communication quality.
[0026]
According to a sixth aspect of the present invention, in the invention according to the fifth aspect, a change in a specific polarization component is reflected toward the incident end side of the light of the core wire at the emission end side of the light of the core wire, The gist of the present invention is to detect the fluctuation of the reflected specific polarization component on the incident end side of the light of the cord.
[0027]
The gist of the present invention described in claim 7 is that, in the invention described in claim 5, the fluctuation of the specific polarization component is detected on the light emitting end side of the core wire.
[0028]
According to an eighth aspect of the present invention, in the invention of the fifth to seventh aspects, only the specific polarization component is incident on the core.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a cord control test apparatus and a cord control test method of the present invention will be described with reference to the drawings.
It should be noted that the following embodiments are merely for explanation of the present invention, and do not limit the scope of the present invention. Therefore, those skilled in the art can adopt various embodiments including each of these elements or all the elements, but these embodiments are also included in the scope of the present invention.
[0030]
"First Embodiment"
FIG. 1 is a block diagram showing a configuration of a core wire comparison test apparatus 1a according to the first embodiment of the present invention.
In the drawing, the intra-station device 2 and the terminal-side device 5 are connected via the branch module 3 and the optical fiber 4a, and the communication light 6 is transmitted by the optical fiber 4a.
[0031]
The optical fiber contrast test apparatus 1a is for performing an optical fiber contrast test on the optical fiber 4a, that is, the working line, and includes a test light transmitting unit 11, an optical coupler 14, a test light receiving unit 15, and a reflecting unit 18. And a position changing unit 19.
[0032]
The test light transmitting unit 11 is located on the incident end side of the light of the core wire 4a, performs light polarization on the test light with the light source 12 that generates the test light, and converts only a specific polarization component of the test light into light. And a polarizer 13 to be incident on the coupler 14. In the present embodiment, a case where the specific polarization component is a linear polarization component is shown. However, the present invention is not limited to this, and another polarization component may be made to enter the optical coupler 14. .
[0033]
The optical coupler 14 causes the test light polarized by the polarizer 13 to enter the core wire 4 a via the branch module 3. The incident test light (hereinafter, referred to as test light 7) propagates in the cord 4a.
[0034]
Not only the linear polarization component, but also the polarization component of light fluctuates by slightly changing the position of the core wire without bending the core wire as in the conventional example.
[0035]
The position changing unit 19 applies a force (vibration) in the short direction of the core wire 4a to slightly change the position of the core wire 4a. As a result, the phase of the linearly polarized component fluctuates.
[0036]
The reflection unit 18 is located on the light emitting end side of the core wire 4a, and includes a filter member that reflects a linearly polarized component of the test light 7 and transmits the communication light 6.
[0037]
The linearly polarized component reflected by the reflecting portion 18 propagates through the core wire 4 a again, and is incident on the optical coupler 14 by the branch module 3. The optical coupler 14 makes the linearly polarized component enter the test light receiving unit 15.
[0038]
The test light receiving unit 15 is located on the light incident end side of the core wire 4a and includes a polarizer 16 similar to the above-described polarizer 13 and a measuring unit 17, and the measuring unit 17 includes a position changing unit 19 The fluctuation of the linearly polarized wave component caused by the action is detected, and the fluctuation amount is measured. Thereby, those skilled in the art can confirm that the cord 4a is the cord to be worked.
The polarizer 16 is for improving the detection accuracy of the linearly polarized wave component.
[0039]
FIG. 2 is a diagram showing the intensity of the linearly polarized wave component when the position of the core wire 4a in FIG. 1 is not changed.
This figure shows a case where the core wire 4a is laid outdoors. Although the intensity varies due to various environmental factors, the amount of the variation is extremely small.
[0040]
FIG. 3 shows the intensity fluctuation amount of the linear polarization component when the position of the above-mentioned core wire 4a is changed by the core wire comparison test apparatus 1a in FIG.
Only when the position of the core wire 4a is changed, a sharp intensity change occurs as indicated by a circle in the figure. Further, although the position of the core wire 4a is changed, no intensity fluctuation occurs in the light having the wavelength of 1.625 μm.
[0041]
The above points suggest that the core control test apparatus of the present invention can perform the core control test on the working line without deteriorating the communication quality. Also suggests that it is possible to perform a core control test on the working line without deteriorating the communication quality.
[0042]
"Second embodiment"
FIG. 4 is a block diagram showing a configuration of a core-wire contrast test device 1b according to the second embodiment of the present invention.
The core control test device 1a of FIG. 1 is for performing a core control test on the working line, but the core control test device 1b of FIG. This is for performing a core line contrast test on the wire 4a), and includes a test light transmitting unit 11, an optical coupler 14, a test light receiving unit 15, a reflecting unit 18, and a position changing unit 19.
[0043]
The test light transmitting unit 11 is located on the incident end side of the light of the core wire 4a, performs light polarization on the test light with the light source 12 that generates the test light, and converts only a specific polarization component of the test light into light. And a polarizer 13 to be incident on the coupler 14. In the present embodiment, a case where the specific polarization component is a linear polarization component is shown. However, the present invention is not limited to this, and another polarization component may be made to enter the optical coupler 14. .
[0044]
The optical coupler 14 causes the test light polarized by the polarizer 13 to enter the core wire 4 a via the branch module 3. The incident test light (hereinafter, referred to as test light 7) propagates in the cord 4a.
[0045]
Not only the linear polarization component, but also the polarization component of light fluctuates by slightly changing the position of the core wire without bending the core wire as in the conventional example.
[0046]
The position changing unit 19 applies a force (vibration) in the short direction of the core wire 4a to slightly change the position of the core wire 4a. As a result, the phase of the linearly polarized component fluctuates.
[0047]
The reflection unit 18 is located on the light emitting end side of the core wire 4a and reflects the linearly polarized wave component of the test light 7. Note that the reflecting section 18 in the present embodiment is a case where the reflecting section 18 is the open end of the core wire 4a.
[0048]
The linearly polarized component reflected by the reflecting portion 18 propagates through the core wire 4 a again, and is incident on the optical coupler 14 by the branch module 3. The optical coupler 14 makes the linearly polarized component enter the test light receiving unit 15.
[0049]
The test light receiving unit 15 is located on the light incident end side of the core wire 4a and includes a polarizer 16 similar to the above-described polarizer 13 and a measuring unit 17, and the measuring unit 17 includes a position changing unit 19 The fluctuation of the linearly polarized wave component caused by the action is detected, and the fluctuation amount is measured. Thereby, those skilled in the art can confirm that the cord 4a is the cord to be worked.
The polarizer 16 is for improving the detection accuracy of the linearly polarized wave component.
[0050]
FIG. 5 is a diagram showing the intensity of the linear polarization component when no change is applied to the position of the core wire 4a in FIG.
This figure shows a case where the core wire 4a is laid outdoors. Although the intensity varies due to various environmental factors, the amount of the variation is extremely small.
[0051]
FIG. 6 shows the intensity fluctuation amount of the linearly polarized wave component when the position of the above-mentioned core wire 4a is changed by the core wire comparison test apparatus 1b in FIG.
Only when the position of the core wire 4a is changed, a sharp intensity change occurs as indicated by a circle in the figure.
[0052]
Also, when conducting a core contrast test on a non-working line, the core wire that was recognized by those skilled in the art as a non-working line is actually a working line, and communication light may be propagated. .
Assuming such a situation, light having a wavelength of 1.55 μm is incident on the core wire 4b, and the position of the core wire 4b is changed by a position change unit (not shown) similar to the position change unit 19, and Was measured, but as shown in the measurement results in the figure, despite the change in the position of the core wire 4b, no intensity fluctuation occurred in light having a wavelength of 1.55 μm.
[0053]
The above points suggest that the core control test apparatus of the present invention can perform the core control test on the working line without deteriorating the communication quality. Also suggests that it is possible to perform a core control test on the working line without deteriorating the communication quality.
[0054]
In addition, the wavelength of the test light in the present embodiment may be the same as the wavelength of the communication light, and therefore, the light source can be shared and the cost can be reduced.
[0055]
In addition, the above-mentioned core wire contrast test devices 1a and 1b calculate the amount of variation of the linearly polarized component reflected by the reflector 18 located on the light emitting end side of the light of the core wire 4a on the light emitting end side of the light of the core wire 4a. The measurement is performed by the test light receiving unit 15 located at the position (1), but is not limited to this. For example, it is also possible to adopt a configuration in which the reflection section 18 is not provided, and the test light receiving section 15 is arranged on the light emitting end side of the core wire 4a.
[0056]
FIG. 7 is a sequence diagram showing the operation of the core-wire test apparatus 1a of FIG. 1 and the core-wire test apparatus 1b of FIG.
The test light transmitting unit 11 extracts only the linearly polarized wave component of the test light by performing polarization, and makes the test light incident on the optical coupler 14 (S1). The optical coupler 14 makes the test light incident on the branch module 3, and the branch module 3 sets the path of the test light and makes it incident on the core wire 4a (S2). The test light propagates in the core wire 4a (S3), and the position change unit changes the position of the core wire 4a, thereby causing a change in the phase of the linearly polarized component of the test light (S4). When a core line contrast test is performed on the working line, in S2, the signal light and the test light are multiplexed and incident on the core line 4a.
[0057]
Next, the test light is reflected by the reflector 18 (S5), and the reflected light propagates in the core wire 4a (S6), and the branching module 3 sets a path of the reflected light and makes the reflected light incident on the optical coupler 14 ( S7). The optical coupler 14 distributes the reflected light and causes the reflected light to enter the test light receiving unit 15 (S8). The test light receiving unit 15 performs the polarization again to improve the detection accuracy (S9), and measures the amount of change of the linearly polarized component caused by the operation of the position changing unit 19 (S10).
[0058]
【The invention's effect】
As described above, the cord control test apparatus and the cord control test method of the present invention perform the cord control by detecting only a change in a specific polarization component of light. This variation does not affect the intensity of long-wavelength communication light propagating in the core wire because it occurs only by slightly changing the position without bending the core wire. Therefore, the core line comparison test can be performed on the working line without deteriorating the communication quality.
In view of the above, it is possible to provide a core-line test apparatus and a core-line test method capable of performing a core-line test without deteriorating communication quality.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of a core-wire contrast test apparatus according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating the intensity of a linearly polarized wave component when no change is made to the position of the core wire.
FIG. 3 is a diagram showing a fluctuation amount of a specific linearly polarized wave component measured by the optical fiber line test apparatus of FIG. 1;
FIG. 4 is a block diagram showing a configuration of a core wire contrast test apparatus according to a second embodiment of the present invention.
FIG. 5 is a diagram showing the intensity of a linearly polarized wave component when no change is made to the position of the cord.
FIG. 6 is a diagram showing a variation amount of a specific linearly polarized wave component measured by the optical fiber line contrast test apparatus of FIG. 4;
FIG. 7 is a sequence diagram showing an operation of the core wire comparison test device of FIGS. 1 and 4;
FIG. 8 is a block diagram illustrating a configuration of a conventional core wire contrast test apparatus.
FIG. 9 is a block diagram showing a configuration of a conventional core wire contrast test apparatus.
FIG. 10 is a diagram illustrating wavelength dependence of a loss caused by bending a core wire.
[Explanation of symbols]
1a, 1b Optical fiber contrast test apparatus 2 In-house equipment 3 Branch module 4a, 4b, 4c, 4d Optical fiber 5 Terminating device 6 Communication light 7 Test light 8 Reflected light 11 Test light transmitting unit 12 Light source 13, 16 Polarizer 14 Light Coupler 15 Test light receiving unit 17 Measurement unit 18 Reflecting unit 19 Position changing unit

Claims (8)

An optical fiber contrast test device for performing an optical fiber contrast test on the optical fiber by injecting light into the optical fiber of the optical fiber and detecting the light,
Position changing means for changing the position of the cord,
And a variation detecting means for detecting a variation in a specific polarization component of the light caused by a change in the position of the cord. The fluctuation detecting means is located on the incident end side of the light of the core wire, and the specific polarization component reflected toward the incident end side of the light of the core wire on the emission end side of the light of the core wire. 2. The apparatus according to claim 1, wherein the apparatus detects a variation. 2. The optical fiber contrast test apparatus according to claim 1, wherein the fluctuation detecting unit is located on a light emitting end side of the optical fiber. 3. 4. The optical fiber contrast test apparatus according to claim 1, further comprising a specific polarization component incident unit that causes only the specific polarization component to enter the core. 5. A core wire contrast test method for performing a core wire contrast test for the core wire by irradiating light to the core wire of the optical fiber and detecting the light,
Changing the position of the cord,
A method for testing a core line, comprising detecting a change in a specific polarization component of the light caused by a change in the position of the core line. The specific polarization component is reflected toward the incident end side of the light of the core wire at the emission end side of the light of the core wire,
6. The test method according to claim 5, wherein a change in the reflected specific polarization component is detected at a light incident end side of the optical fiber. 6. The test method according to claim 5, wherein the variation of the specific polarization component is detected on the light emitting end side of the core wire. 8. The test method according to claim 5, wherein only the specific polarization component is incident on the core.

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