JPS6330092A - Wavelength split type optical exchange channel - Google Patents

Abstract

PURPOSE:To attain the exchange between wavelengths by demultiplexing a wavelength- multiplexed optical signal of an input highway and adding the signal to a wavelength converter selected by an optical switch to convert the signal into the optical signal of other wavelength, multiplexing the outputs of each wavelength converter to output a wavelength-multiplexed optical signal to an output highway. CONSTITUTION:A wavelength-multiplexed optical signal from an input highway comprising optical fibers is inputted to a demultiplexer 1, the signal is demultiplexed to wavelengths lambda1-lambdan, they are inputted to a space split type optical switch 2. the optical switch 2 is controlled by the information read from a control memory 5, for example, the optical signal of wavelength lambda1 is fed to a wavelength converter 3 outputting the optical signal of wavelength lambdan and the optical signal of wavelength lambdan is fed to the wavelength converter 3 outputting the optical signal of wavelength lambda1, the optical signal of wavelength lambda1 of the input highway is converted into the wavelength lambdan and the optical signal of wavelength lambdan is converted into the wavelength lambda1 respectively. The optical signal from each wavelength converter 3 is multiplexed by a multiplexer 4 and the wavelength multiplex optical signal having wavelengths lambda1-lambdan is sent to an output highway.

Description

[Detailed Description of the Invention] [Summary] A wavelength converter is provided which inputs an optical signal of any one of wavelengths λ, -λ7 and outputs an optical signal of a specific wavelength, and converts the input highway wavelengths λ1 to λ7. By demultiplexing the multiplexed optical signal and applying the optical signal to a wavelength converter selected by an optical switch, it is converted into an optical signal of another wavelength, and the outputs of each wavelength converter are combined to form an output highway. It outputs wavelength multiplexed optical signals and performs switching between wavelengths.

[Industrial application field]

The present invention relates to a wavelength-division optical switching channel that realizes conversion of a wavelength-multiplexed optical signal into a desired wavelength of an optical signal of each wavelength.

Various methods have been proposed in which audio signals, image signals, various data, and the like are transmitted as optical signals and exchanged and connected using an optical switch. Furthermore, in order to improve the multiplicity of the transmission path, a method for transmitting wavelength multiplexed optical signals has been developed. There is also a demand for switching and connecting such wavelength-multiplexed optical signals using an optical switch.

[Conventional technology]

An optical switch that performs switching and connection of wavelength-multiplexed optical signals requires a wavelength division type optical switch that performs switching and connection of optical signals according to wavelength. Conventionally, for example, as shown in FIG. 5, a wavelength multiplexed optical signal with wavelengths λ1 to λ0 is input from an input highway, is demultiplexed by a demultiplexer 21 according to the wavelength, and is applied to a wavelength converter 22. The wavelength-converted optical signals are multiplexed by a multiplexer 23 and sent to the output highway with wavelengths λ1 to λ7.
A multiplexed optical signal is output.

In that case, control information written in the control memory 24 from a control unit (not shown) is read out, and the wavelength converter 22 is controlled, for example, converting an optical signal of wavelength λ to any one of wavelengths λ1 to λ7. It converts it into a wavelength and outputs it. That is, an optical signal of a wavelength corresponding to an input highway is exchanged with an optical signal of the same or another wavelength, multiplexed onto an output highway, and sent out.

FIG. 6 shows a block diagram of the conventional wavelength converter shown in FIG.
The optical signals (i=1 to n) are converted into electrical signals by a light receiving element 30 consisting of a photodiode, a phototransistor, etc. It will be done. Each of the light emitting elements 31 to 3n is controlled according to the control information read from the control memory 24, converted into an optical signal having one of the wavelengths λ1 to λ1, output, and added to the multiplexer 23. .

Currently, a configuration in which a single light emitting element selectively generates optical signals of different wavelengths has not been realized, so as described above, light emitting elements 31 to 3n corresponding to wavelengths λ1 to λ1 are provided.

[Problem that the invention seeks to solve]

The wavelength converter 22 in the conventional example described above has wavelengths λ1 to λ
Since the light emitting elements 31 to 3n corresponding to 7 are required, the total number of light emitting elements is nXn. Therefore, the configuration of wavelength division optical switching communication is complicated and expensive.

In addition, after the optical signal is converted into an electrical signal by the light receiving element 30, it is distributed to the light emitting elements 31 to 3n corresponding to wavelengths λ8 to λ7, so the wiring length of the electrical part is long (and is affected by band limitations due to stray capacitance). Therefore, there was a problem in that it was not possible to take advantage of the broadband nature of light.

[Means for solving problems]

The wavelength division optical switching channel of the present invention will be explained with reference to FIG. A wavelength multiplexed optical signal with wavelengths λ1 to λ7 is input from an input highway to a demultiplexer 1, split into optical signals corresponding to wavelengths λ1 to λ7, and input into a space division type optical switch 2. The space division type optical switch 2 is controlled according to the control information read from the control memory 5, and the wavelength converter 3 having the desired output wavelength is selected. No matter which of the optical signals with wavelengths λ1 to λ7 is input, an optical signal with a predetermined wavelength is output, and each wavelength converter 3 outputs an optical signal with a predetermined wavelength.

The optical signal of ~λ7 is applied to the multiplexer 4, and a wavelength multiplexed signal is sent out to the output highway.

[Effect]

The wavelength-multiplexed optical signals of input highway wavelengths λ, to λ7 are demultiplexed by a demultiplexer 1 into corresponding wavelengths, and are applied to a wavelength converter 3 of a desired output wavelength by a space-division optical switch 2. Since each wavelength converter 3 generates an optical signal with a predetermined wavelength, it includes one light emitting element, and the light receiving element converts an optical signal with a relatively wide wavelength range into an electrical signal. Therefore, only one light receiving element is required. For example, since an optical signal with a wavelength λ1 is applied to a wavelength converter 3 selected by a space-division optical switch 2, the wavelength λ1 is applied.

~λ7 and output, and the optical signals wavelength-converted by each wavelength converter 3 are combined by a multiplexer 4 to become a wavelength-multiplexed optical signal and sent to the output highway. .

[Examples] Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, in which wavelength-multiplexed optical signals with wavelengths λ1 to λ7 are input to a demultiplexer through an input highway consisting of an optical fiber.
The signal is demultiplexed and input to the space-division optical switch 2. This space-division optical switch 2 is controlled according to control information read out from a control memory 5. For example, an optical signal with a wavelength λ is applied to a wavelength converter 3 that outputs an optical signal with a wavelength λ7; The optical signal of λ is applied to a wavelength converter 3 which outputs an optical signal of wavelength λ1, and the optical signal of input highway wavelength λ1 is converted to wavelength λ1, and the optical signal of wavelength λ1 of the input highway is converted to wavelength λ1.
The optical signals of 7 will be exchanged to wavelength λ1, respectively. Since the optical signals from each wavelength converter 3 are multiplexed by the multiplexer 4, wavelength multiplexed optical signals with wavelengths λ, to λ7 are sent out to the output highway.

Therefore, by controlling the space-division optical switch 2, the optical signal wavelength on the input highway can be exchanged with a different wavelength and output on the output highway.

FIG. 2 shows a block diagram of the wavelength converter 3 described above, with 11
12 is a light-receiving element into which optical signals of wavelengths λ1 to λ7 are input and converts them into electrical signals; 12 is a light receiving element of a specific wavelength λ+ (i=1 to n
) is a light emitting element that outputs an optical signal. Since the light receiving element 11 can convert an optical signal with a relatively wide wavelength range into an electrical signal, even if the optical switch 2 selects an optical signal with one of the wavelengths λ1 to λ1, it can convert it into an electrical signal. Thus, the light emitting element 12 can be driven to output an optical signal of a predetermined wavelength.

Further, the wavelength converter 3 can also be configured using an optically pumped semiconductor laser or the like.

FIG. 3 is an explanatory diagram of an optical switch, for example, L i
A waveguide 14 is formed by diffusing Ti into a N b 03 substrate 14.
are formed to intersect, electrodes 15 and 16 are provided near the intersection, electrode 16 is grounded, and a voltage is applied to the electrode 15 from terminal 17, the refractive index at the intersection of the waveguide 14 changes, Since total reflection conditions can be created, the incident light is totally reflected and output as reflected light. Also terminal 1
When no voltage is applied to 7, the incident light travels straight and is output as transmitted light. Therefore, depending on whether or not a voltage is applied to the terminal 17, it is possible to switch and connect the incident light.

A space division type optical switch 2 can be configured by integrating a plurality of such optical switches on a L i N b 03 substrate. Further, the space division type optical switch 2 can also be configured using a directional coupling type optical switch, a Bragg diffraction type optical switch, or the like.

FIG. 4 is a block diagram of another embodiment of the present invention, in which the optical switch is configured to correspond to wavelengths λ1 to λ7 when the optical switch has wavelength dependence. In the figure, 21 is a demultiplexer, 22-1 to 22-n are lxH optical switches corresponding to wavelengths λ1 to λ7, which together constitute a space-division type optical switch, and 23-1 to 23-n are optical switches for wavelengths λ1 to λ7. Wave equipment, 2
4-1 to 24-n are wavelength converters corresponding to wavelengths λ1 to λ7;
25 is a multiplexer connected to the output highway, and 26 is a control memory.

The wavelength-multiplexed optical signals having wavelengths λ1 to λ7 on the input highway are demultiplexed by the demultiplexer 21 according to the wavelengths λ1 to λ7, and are applied to the optical switches 22-1 to 22-n. Each of the optical switches 22-1 to 22-n can be configured, for example, by combining total reflection type optical switches shown in FIG. Moreover, a high-speed operation optical switch can be constructed.

The optical switches 22-1 to 22-n each have wavelengths λ1 to 22-n.
An optical signal of λ1 is output and applied to wavelength converters 24-1 to 24-n via multiplexers 23-1 to 23-n. Each of the wavelength converters 24-1 to 24-n has the configuration shown in FIG. 2, for example. And each wavelength converter 24
-1 to 24-n output optical signals with wavelengths λ and ~λ, respectively, which are combined by a multiplexer 25 and sent to the output highway as wavelength-multiplexed optical signals with wavelengths λ1 to λ7.

For example, when exchanging an optical signal with a wavelength λ1 on an input highway to a wavelength λ7 on an output highway, the optical signal with a wavelength λ1 demultiplexed by the demultiplexer 21 is transferred to the multiplexer 23- by controlling the optical switch 22-1. In addition to the wavelength λ, an optical signal with a wavelength λ is added from the multiplexer 23-n to the wavelength converter 24-n to output an optical signal with a wavelength λ, which is multiplexed by the multiplexer 25. .

〔Effect of the invention〕

As explained above, in the present invention, the demultiplexer 1 demultiplexes the wavelength-multiplexed optical signal of the input highway wavelengths λ1 to λ7 according to the wavelength, and the space-division optical switch 2 demultiplexes the demultiplexed optical signal. In addition to the wavelength converter 3 by spatially switching the connection,
The optical signal from the wavelength converter 3 is multiplexed by the multiplexer 4, and since the wavelength converter 3 has a configuration that can output an optical signal of a predetermined wavelength, for example, as shown in FIG. This can be realized by the configuration, and there is an advantage that wavelength division type optical switching communication can be configured economically.

Also, since the electrical signal wiring length of the wavelength converter can be shortened,
The influence of band limitations caused by stray capacitance can be reduced, and high-speed optical signals can be exchanged by taking advantage of the broadband nature of light.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a block diagram of a wavelength converter according to an embodiment of the present invention, FIG. 3 is an explanatory diagram of an optical switch, and FIG. 4 is a block diagram of another embodiment of the present invention. FIG. 5 is a block diagram of the embodiment, FIG. 5 is a block diagram of a conventional example, and FIG. 6 is a block diagram of a conventional wavelength converter. λ, ~λ are wavelengths of optical signals, 1 is a demultiplexer, 2 is a space-division optical switch, 3 is a wavelength converter, 4 is a multiplexer, 5 is a control memory, 21 is a demultiplexer, 22- 1 to 22-n are optical switches, 23-1 to 23-n are multiplexers, 24-1 to 14-n
25 is a wavelength converter, 25 is a multiplexer, and 26 is a control memory.

Claims (1)

[Claims] A demultiplexer (1) that demultiplexes a wavelength-multiplexed optical signal from an input highway according to wavelength, and spatially switches the connection of the optical signals demultiplexed by the demultiplexer (1). a space-division type optical switch (2) that outputs an optical signal of a predetermined wavelength by inputting optical signals of various wavelengths output from the space-division type optical switch (2); A converter (3) and a multiplexer (4) that multiplexes optical signals from each wavelength converter (3) corresponding to the wavelength and outputs a wavelength-multiplexed optical signal to an output highway. Features a wavelength-division optical switching channel.