JPS6032030A - Optical control type optical multiplexer/demultiplexer device - Google Patents

Abstract

PURPOSE:To attain high-speed response, small-sized constitution and high reliability by forming waveguide optical switches connected like a tree and actuated by an electrooptical effect. CONSTITUTION:Light 11 incident on an input optical waveguide 2a is reflected by the 1st (81) waveguide optical switch 2, outputted to a waveguide 2c and then guided to an input optical waveguide of the 2nd (82) waveguide optical switch 2'. The light is straightly guided by the waveguide optical switch 2', guided to an input optical waveguide 26a of the 3rd (83) waveguide optical switch 2'' by an optical waveguide 36 through an optical waveguide 26a, reflected by the waveguide optical switch 2'' and outputted to an optical waveguide 26b to obtain output light 12. When light is inputted to the waveguide 26b, the light is outputted from the optical waveguide 2a. Thus, an I/O optical waveguide can be connected to one O/I optical waveguide out of 2<3> O/I optical waveguides in accordance with the state (lambda1, lambda2, lambda3)=(a1, a2, a3) of control light. Namely electromagnetically induced noise can be prevented by connecting the waveguide optical switches like a tree on the same substrate and attaining high-speed response, small-sized constitution and high reliability and performing control through light.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to optical communications and optical applied measurement and control.

Conventional configuration and its problems In an optical switch that switches the optical path by a control signal applied from the outside, one output optical waveguide is connected to one of a plurality of input optical waveguides specified by the control signal. , the light wave propagating through the connected input optical waveguide,
A device that outputs light into the output side optical waveguide is called an optical multiplexer. Moreover, in such a device, a device in which the propagation direction of light waves is opposite is called an optical demultiplexer.

Conventionally, optical multiplexers and demultiplexers have been constructed from mechanical optical switches using movable prisms, movable mirrors, and the like.

Since these devices must be equipped with an electromagnetic solenoid and an electric motor to drive the optical switch, they have the disadvantage that the device is large and the switch response is slow, ranging from several milliseconds to several tens of milliseconds. In addition, since it has moving parts, there are reliability problems such as fluctuations in output due to mechanical vibrations, and problems with longevity due to mechanical wear. Furthermore, since the optical switches are operated mechanically, they have the drawback of requiring a large amount of driving power, and the drawback of requiring a complicated control system to selectively drive a large number of optical switches.

Furthermore, since electricity is used for the control signal, there is a problem that it is susceptible to electromagnetic induction noise and may malfunction.

Purpose of the Invention The present invention achieves high-speed response, miniaturization, high reliability, and The purpose is to extend the life of the product. Another object of the present invention is to provide an optically controlled optical multiplexer demultiplexer device that requires low driving power and is easy to control.

Another object of the present invention is to provide an optically controlled optical multiplexer/demultiplexer device that is resistant to electromagnetic induction noise.

Structure of the Invention The present invention has at least one input/output optical waveguide in the input/output section, and has two or more output/input optical waveguides in the output/input section, and has a plurality of control lights. In an optically controlled optical multiplexer/demultiplexer device that distributes/collects input light and takes it out to an output section, at least one input/output optical waveguide, two output/input optical waveguides, and an electro-optic effect are provided on the main surface of the substrate. a waveguide optical switch having an optical switch portion capable of switching the waveguide of light propagating in the input optical waveguide, and a waveguide optical switch formed on the main surface of the substrate, the number of stages being equal to the number of stages of the waveguide optical switch; , has a waveguide optical switch of each stage number and a photovoltaic element corresponding to the stage number, and the input/output optical waveguide of the waveguide optical switch is one output/input optical waveguide of the previous stage waveguide optical switch. and the two output/input optical waveguides of the waveguide optical switch are respectively connected to the input/output optical waveguides of the subsequent waveguide optical switch. A driving electrode formed on the optical switch portion of the switch is electrically connected to an electrode of each photovoltaic element corresponding to each stage of the waveguide optical switch, and the waveguide light of each stage is electrically connected to each other. The driving electrodes formed on each optical switch part of the switch are electrically connected to each other, and control light is irradiated to photovoltaic elements corresponding to the number of stages in accordance with the number of stages. An optically controlled optical multiplexer/demultiplexer device is provided.

DESCRIPTION OF EMBODIMENTS The present invention achieves high-speed response, miniaturization, high reliability, and long life by fabricating waveguide optical switches operated by electro-optic effect connected in a tree shape (described later) on the same substrate. By using a structure in which the electrodes of the tree-connected waveguide optical switch are electrically connected to each stage, it is easy to control the address of the waveguide to be selected. In addition, the control signal voltage of each waveguide switch is supplied from the photovoltaic voltage generated when a photovoltaic element is irradiated with control light, thereby creating an optically controlled optical multiplexer/demultiplexer that is resistant to electromagnetic induction noise. Provide equipment.

Embodiments of the optically controlled optical multiplexer/demultiplexer device of the present invention will be described below.

Figure 1 shows the number of poles 1×2 when n=3 in the present invention.
3 shows an example of the optically controlled optical multiplexer/demultiplexer of No. 3. In FIG. 1, a substrate 1 is made of LiNbO3 single crystal. The waveguide optical switches are connected in a tree shape on the substrate 1, that is, the first stage 81 has a number of poles of 2×2.
waveguide optical switch 2 and its two output/input optical waveguides 2b.

2C by connecting leading waveguides 31 and 32, respectively.
One of the two input/output optical waveguides of each second stage 82 waveguide optical switch 2' 21 &, 2
2a. 22 (=4) output/input optical waveguides 21b of the second stage 82 waveguide optical switch 2';
! 10, 22b, and 220(7) are connected to one of the two input/output optical waveguides of each of the 22 third-stage 83 waveguide optical switches 2'' using the connection optical waveguides 33 to 36. 23a.

24! It is connected to L, 251L, 26&. 23 output/input optical waveguides 23b, 230, 24b, 240 of the waveguide optical switch f of the third stage 83.

25b, 250, 26b, and 260 are output/input optical waveguides. The input/output optical waveguide 2a of the waveguide optical switch 2 in the first stage 81 serves as its manual/output optical waveguide. The electrode 41 of the waveguide optical switch in the first stage 81 is connected to the photovoltaic element 4 such as the first single-crystal Si solar cell, and the two waveguide optical switches in the second stage 82 are connected in parallel. The electrodes 42 connected in parallel are connected to the second photovoltaic element 4', and the parallel-connected electrodes 43 of the waveguide optical switch of the third stage 83 are connected to the third photovoltaic element 4'.

Wavelength λ1. λ2. λ3 control light 7.7',? ' irradiates each photovoltaic element 4.4', 4''. Among the photovoltaic elements 4, 4/, 4//, the element irradiated with the control light generates a photovoltaic voltage, and the element Therefore, the wavelength λ1°λ2 .
The waveguide optical switches in the 1st, 2nd, and 3rd stages can be independently controlled by the control light of λ3.

FIG. 2 shows an enlarged view of the configuration of one waveguide optical switch 2.2', 2'θ. In the figure, the optical waveguide 5
1.54, 52.53 is a total internal reflection (TIR) type waveguide optical switch with width w = 1 opm and crossing angle ψ of 20°. 61 is 22a, 26 in Figure 1
1L, 24a, etc., 52 corresponds to 2a, 21a, 23
a, 26a, etc., 63 corresponds to 21), 21b, 22b
, 23b, 24b, 25b26b, 64 is 210,
220, 230, 240250.260. The light 57 incident on the input optical waveguide 61 is divided into straight light 68 and reflected light 69 depending on the magnitude of the photovoltaic voltage 66 applied to the electrode 66, and is outputted to the output optical waveguides 54 and 53, respectively. FIG. 3 shows an example of a TIFI type waveguide type optical wave path optical switch. In the figure, when the photovoltaic voltage is 0, it is in the off state, and when the photovoltaic voltage is equal to or higher than the on voltage, it is in the on state.

The optical waveguide described above is made by attaching a 20 um thick Ti metal to a substrate for 4 hours in N2 at a temperature of 960'C.
Produced by time heat diffusion. The waveguide optical switch is small, highly reliable, has no moving parts, has a long life, has a high-speed response of 5 sHz or more, and requires low driving power. By connecting each switch using a built-in optical waveguide for connection, the present device has all of the above-mentioned features and has the feature of high reliability as a whole.

Next, the operation of the optically controlled optical multiplexer/demultiplexer will be explained.

In Fig. 1, the state of the first stage (i = 1.2.s) waveguide optical switch is expressed by al, and when it is in the off state, ai
=o, when it is on, ! It is written as Li=1. For example, the control lights of wavelengths λ1 and λ3 correspond to the 1st and 3rd stages, 81.
A case will be described in which the waveguide optical switch 83 is turned on, and the control light having the wavelength λ2 turns off the corresponding waveguide optical switch 82 at the second stage. The state of the optical multiplexer/demultiplexer at this time is (al, 21
``3)-('.

0.1). Light 11 incident on the input optical waveguide 2a
is reflected by the waveguide optical switch 2 of the first stage 81 and output to the waveguide 2C, and guided by the connecting optical waveguide 32 to the input optical waveguide of the waveguide optical switch 2' of the second stage 82. After that, go straight through the waveguide optical switch 2', and go straight to the optical waveguide 22.
c, the light is guided by the optical waveguide 36 to the input optical waveguide 26a of the waveguide optical switch 1 of the third stage 83, reflected by the waveguide optical switch 2', and output to the optical waveguide 26b to obtain the output light 12. Further, at this time, the propagation of light is reversible, and when light is input to the waveguide 26b, it is output to the optical waveguide 2a. As mentioned above, the state of control light (λ1.λ2.λ3)=(al
e &2 m'3), the input/output optical waveguide can be connected to one of the 24 output input optical waveguides.

As described above, control can be easily achieved by combining control lights.

The present invention has the advantage that since the control is performed using light, the control signal light is not subjected to electromagnetic induction during transmission.

In addition, in the above embodiment, T is used as a waveguide optical switch.
An example of an IR type branch waveguide optical switch will be explained, but a 2x2 directional genital waveguide optical switch as shown in Fig. 4 or a 1x2 directional genital waveguide optical switch as shown in Fig. 5 will be described. An optically controlled optical multiplexer/demultiplexer can be similarly constructed using a switch, a branched waveguide optical switch shown in FIG. 6, or the like.

In addition, in the above embodiment, LiNbO5 is used for the substrate 1,
Although an example of a Ti-diffused LiNbO3 waveguide is shown as an optical waveguide, any substrate and optical waveguide may be used as long as it is possible to form an optical waveguide having an electro-optic effect.
There is no need to limit it to iNbO3.

Furthermore, the photovoltaic element is not limited to a single crystal Si solar cell, and may be an amorphous Si solar cell, a Gaps solar cell, an n-Vl group 9-V group compound semiconductor diagonally deposited film such as Zn5e, GaAs, etc. Any material may be used as long as it satisfies the above functions. Of course, the number of output/input optical waveguides of the device of the present invention may be 2a or less.

Effects of the Invention In the present invention, by creating a structure in which waveguide optical switches are connected in a tree shape on the same substrate, it is possible to achieve faster response, smaller size, higher reliability, longer life, lower driving power,
This has the effect of ease of control. Since the control is performed using light, there is no electromagnetic induction noise during the control signal transmission system, so optical multiplexers and optical multiplexers that are resistant to electromagnetic induction noise
A demultiplexer device can be provided.

[Brief explanation of drawings]

FIG. 1 is a top view showing an embodiment of the optically controlled optical multiplexer/demultiplexer device according to the present invention in the case of 1l=3, and FIG. 2 is an example of the TIR type branch waveguide optical switch used in this embodiment. 3 is a switch characteristic diagram of the optical switch shown in FIG. 2, and FIG. 4 is a top view showing a directional coupler type 2×2 waveguide optical switch. Fig. 6 is a top view showing an example of a directional coupler type switch, and Fig. 6 is a top view showing an example of a directional coupler type directional coupler type switch. In the figure, a is a top view showing an example of a directional coupler type, and a is a top view of a directional coupler type.
FIG. 6 is a top view showing an example of a β-inversion type directional coupler type, and FIG. 6 is a top view showing an example of a branching type waveguide optical switch. 1... Board, 2, 27, 2''--...
Waveguide optical switch, 2a, 21a, 221L,
23&, 24a, 25a26&... Input/output optical waveguide of waveguide optical switch, 2b, 20.21b
, 210, 22b, 220° 23b, 23Q, 24
b, 240.26b, 260°26b, 260...
...Output/input optical waveguide of waveguide optical switch, 31
~36... Optical waveguide for connection, 4゜4', 4"・
...Photovoltaic element, 41,42.43...
- Electrode, 11... Input light, 12... Output light, 7.7'. 1'...Control light (wavelength λ1.λ2.λ3), 5
1 to 64... Optical waveguide, 56...
・Electrode, 66...Photovoltage, 67...
Incident light, 58... Straight light, 59... Reflected light, 81... First stage (waveguide optical switch), 82... Number 2nd stage (waveguide optical switch)
, 83...Third stage (waveguide optical switch). Name of agent: Patent attorney Toshio Nakao and one other person
2 Figure 1 Figure 3 Figure 984 and H(v) Figure 4

Claims (1)

[Claims] At least one input/output optical waveguide, two output/input optical waveguides, and an optical switch section capable of switching the waveguide of light propagating within the input optical waveguide by an electro-optic effect are provided on the main surface of the substrate. a waveguide optical switch formed on the main surface of the substrate, each stage having the same number of waveguide optical switches as the number of stages of the waveguide optical switch, and a photovoltaic element corresponding to the number of stages, The input/output optical waveguide of the waveguide optical switch is connected to one output/input optical waveguide of the preceding waveguide optical switch, and the two output/input optical waveguides of the waveguide optical switch are The drive electrodes are connected to the input/output optical waveguides of the waveguide optical switches in the subsequent stage, and are connected to the drive electrodes formed on the optical switch parts of the waveguide optical switches in each stage and the respective drive electrodes corresponding to the waveguide optical switches in each stage. The electrodes of the photovoltaic element are electrically connected to each other, and the driving electrodes formed on each optical switch part of the waveguide optical switch in each stage are electrically connected to each other. An optically controlled optical multiplexer/demultiplexer device characterized in that the input light is distributed/collected and delivered to an output section by irradiating control light corresponding to each stage to a photovoltaic element corresponding to each stage. .