JPS6167388A - Optical switch - Google Patents

Abstract

PURPOSE:To attain exchange connection simply without synchronizing a signal subject to wavelength multiplex by setting variably at least one of a wavelength selecting element, a wavelength converting element and a spatial switch in response to a control unit. CONSTITUTION:Wavelength selection elements 3-6 and wavelength converting elements 7-10 are connected in cascade, one terminal is connected to the input, its output is connected to an adder circuit and connected to one output terminal. A control input is given to the elements 3-6 and selected wavelength is controlled switchingly by the control input. A signal subject to wavelength multiplex by wavelengths lambda1-lambda4 comes to the input terminal, the output of the elements 3-6 is controlled by obtaining signals (3)-(6). The elements 7, 8 are not converted among the elements 7-10, the elements 9, 10 convert the signal in wavelength lambda3 into a signal in wavelength lambda4 and converts a signal of wavelength lambda4 into a signal of wavelength lambda3. Thus, the input signal subject to wavelength multiplex in the order ABCD is converted into an output signal in the order of ABDC, for example.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is utilized in optical communication devices. In particular, the present invention relates to an optical switch that passes wavelength multiplexed signals through an exchanger made up of optical circuits.

[Conventional technology]

Conventionally, a wide range of time switches have been used to exchange signals in one communication channel. An example of this is shown in FIG.

The time switch 1 includes a buffer memory, and the signals ta+ that arrive in the order ABCD are input to the time switch 1. For example, the third and fourth signals are swapped and the output is the signal A, B D C in the order ( b) is output.

To swap signals across channels, time-sharing switching switches are used. FIG. 19 shows this example, where the time division exchange switch 2 includes a highway, and the terminals (a+(c) fdl
The signals in (e) are shown in FIG. 20, respectively. That is, A
When a signal in the order of BCD (a signal in the order of al and kukeseha (C) is input to the time/minute i1J exchange switch 2 and an operation is performed to mutually exchange the fourth signal, AB
A signal in the order of CH (dl) and a signal in the order of EFGHO fel are output.

Both of these two examples apply to cases where the input signals are in a mutually synchronized state and are time-division multiplexed. However, for wavelength-multiplexed signals, it is impossible to invert signals or switch signal paths in this manner. For exchanging wavelength-multiplexed signals, for example, a filter, a space switch,
This is done by a device connected in cascade with a filter.

[Problem that the invention seeks to solve]

When a network of optical communication paths is formed, wavelength-multiplexed signals may be transmitted through the optical communication path, and these signals are not necessarily in a mutually synchronized state. Therefore, in order to exchange this signal using a time division switch, synchronization must be achieved at the stage before the switch. Furthermore, switching and connecting wavelength-multiplexed signals using a combination of filters and space switches has the disadvantage that the equipment becomes large.

The present invention solves this problem, and aims to provide an optical switch that easily exchanges and connects wavelength-multiplexed signals without synchronizing them.

[Means for solving problems]

The present invention comprises at least one input terminal into which a signal obtained by wavelength multiplexing a plurality of signals of different wavelengths is input, at least one wavelength selection element whose input is connected to this input terminal, and A wavelength conversion element or a space switch connected to the output of the wavelength selection element, and an output terminal, wherein at least one of the wavelength selection element, the wavelength conversion element, and the space switch is variably controlled according to the control input. It is characterized by being set.

C Embodiment] FIG. 1 is a block diagram of an apparatus according to a first embodiment of the present invention. Reference numerals 3 to 6 are wavelength selection elements, and reference numerals 7 to 8 are wavelength conversion elements. A wavelength selection element and a wavelength conversion element are connected in series, one input terminal is connected to the input thereof, and the outputs thereof are combined by an adder circuit and connected to one output terminal.

A control input is given to the wavelength selection elements 3 to 6, and the selected wavelengths are switched and controlled by the control input.

FIG. 2 is a diagram showing signals of this embodiment device.

This Figure 2 is a diagram of the wavelength region, and the horizontal axis is the wavelength spectrum, not time. (1) to α0) represent the signals (1) to α0) of the signal path shown in Figure 1, respectively. .

A signal ABCD wavelength-multiplexed with wavelengths λ1 to λ4 arrives at the switch input terminal, and is controlled so that the signals shown in (3) to (6) are obtained at the output of each wavelength selection element 3 to 6, respectively. . Of the wavelength conversion elements 7 to 10, elements 7 and 8 do not perform conversion, and elements 9 and 10 convert wavelength λ.
3 is converted into a signal with wavelength λ4, and the signal with wavelength λ4 is converted into a signal with wavelength λ3. With this configuration, the input signal (1) is wavelength-multiplexed in the order of ABCD, but the output signal (2) is switched to 111B of ABDC.

The type of modulation of the signals A-D does not matter.

By switching the selection wavelengths of the wavelength selection elements 3 to 6 according to control inputs, the arrangement order can be arbitrarily switched.

Note that specific examples of this wavelength selection element and wavelength conversion element will be described later.

Such a circuit configuration can generally be implemented for a plurality of n multiplexed signals.

FIG. 3 is a block diagram of a device according to a second embodiment of the present invention. Reference numerals 11 to 14 are wavelength selection elements, and reference numerals 15 to 1 are wavelength selection elements.
8 is a wavelength conversion element. In this example, wavelength selection element 1
1 to 14 are fixed, and the wavelength selection elements 15 to 14 are fixed.
Is there a regulation for 18? An element whose conversion wavelength can be changed and controlled by the It1 input is used.

FIG. 4 is a diagram showing signals of this second embodiment device. Figure 4 (1) (2) (11) to (18) indicate the wavelength spectrum of the signal in the signal path with the corresponding number in Figure 3. In Figure 4, the horizontal axis is wavelength and time. isn't it.

With this configuration as well, it is possible to replace the input signal wavelength-multiplexed in the order of 8 BCDs with the signal wavelength-multiplexed in the order of ABDCs.

Such a circuit configuration can generally be implemented for a plurality of n multiplexed signals.

FIG. 5 is a block diagram of a device according to a third embodiment of the present invention. Reference numerals 19 to 22 are wavelength selection elements, and the selected wavelengths can be switched and controlled by respective control inputs. This example has two input terminals, the first input terminal being connected to the inputs of wavelength selection elements 19 and 20, and the second input terminal being connected to the inputs of wavelength selection elements 21 and 22.

The outputs of wavelength selection elements 19 and 21 are combined by an adder circuit and connected to a first output terminal, and the outputs of wavelength selection elements 20 and 22 are combined by an adder circuit and connected to a second output terminal.

FIG. 6 is a diagram explaining the signals of this device.

This signal is a signal wavelength-multiplexed into two wavelengths λ1 and 7i2, and the signals JK and LM arriving at the two input terminals are rearranged at the output terminal as JM and LK, respectively. This replacement can be switched according to a control input.

This circuit configuration can generally be implemented for m wavelength multiplexed signals for n terminals.

FIG. 7 is a block diagram of an apparatus according to a fourth embodiment of the present invention. Reference numerals 23 to 26 are wavelength selection elements, and reference numerals 27 to 26 are wavelength selection elements.
30 is a space switch. This circuit connects a wavelength selection element and a space switch in cascade, and each wavelength selection element and each space switch are set to be switchable by respective control inputs. In this example, there are two input terminals, and each input terminal is connected to the inputs of two wavelength selection elements.

Each of the space switches 27 to 30 has two outputs, and the two outputs of each of the space switches 27 to 30 are combined by two adder circuits and connected to two output terminals.

FIG. 8 is a diagram illustrating signals of the fourth embodiment. In this example, signals wavelength-multiplexed into two wavelengths λ1 and λ2 are input to two input terminals, JK and LM, respectively.
However, two outputs are simply switched and output as JM and LK, respectively.

This combination of signals can be changed arbitrarily by control input.

This circuit configuration can also generally be implemented for m wavelength-multiplexed signals for n terminals.

Next, the wavelength selection element used in each of the above embodiments will be explained.

FIG. 9 is a diagram showing an example of the configuration of a wavelength selection element.

It is constructed by joining two laser elements with their waveguide layers or active layers. Reference numeral 31 is a wavelength-multiplexed optical signal, reference numeral 32 is a terminal for current injection, and reference numeral 34 is a waveguide layer. Similarly, numeral 33 is a terminal for current injection, and numeral 35 is an active layer. Reference numeral 36 is output light. By controlling the current at the terminal 32, the selected wavelength can be made variable.

FIG. 10 shows a configuration example of another wavelength selection element. This example uses Fabry-Perot resonance.

Reference numeral 37 is a Fabry-Perot resonator, and by controlling the length of this resonator, the wavelength to be selected can be made variable. That is, the signal 36 having the resonant wavelength of this resonator can be extracted from the wavelength-multiplexed signal 31, and the wavelength to be extracted can be changed by changing the resonant wavelength.

FIG. 11 shows yet another example of the configuration of the wavelength selection element. Reference numeral 38 denotes an interference film filter, and by controlling the inclination of this interference film filter, the wavelength of reflected light or transmitted light can be varied, and a signal 36 of a desired wavelength can be selected from the optically multiplexed signal 31. can.

FIG. 12 shows a configuration example of yet another wavelength selection element. Reference numeral 39 denotes a diffraction grating, and by controlling the inclination of the diffraction grating, the wavelength of the reflected light can be changed. therefore,
A signal 36 of a desired wavelength can be selected from the wavelength-multiplexed signals 31.

Next, the wavelength conversion element will be explained.

FIG. 13 shows an example of the configuration of a wavelength conversion element. Reference numeral 4° is a signal of a certain wavelength, reference numeral 41 is an opto-electric conversion element, and reference numeral 42 is an electro-optical conversion element. A signal 40 of a certain wavelength is input to a photoelectric conversion element 41 and converted into an electric signal, and this electric signal is applied to an electro-optic conversion element 42 to be converted into an optical signal of a desired wavelength. This electro-optical conversion element 42 is
By using a light emitting diode or a laser diode and controlling its injection current or temperature, the wavelength of the output signal light can be made variable.

FIG. 14 is a block diagram of an apparatus according to a fifth embodiment of the present invention. Reference numerals 44 to 47 are wavelength switches.

This wavelength switch is, for example, the device described in the first embodiment or the second embodiment.

The number 4th is a space switch. This space switch is a switch that connects optical signals applied to a plurality of input terminals to one of a plurality of output terminals, respectively, according to a control input. Reference numerals 49 to 52 are wavelength switches, and similarly, the devices described in the first embodiment or the second embodiment can be used.

FIG. 15 is an explanatory diagram of signals of the device of the fifth embodiment.

In this example, the circuit sends signals a-p from four input terminals multiplexed into four wavelengths λ1 to λ to four output terminals each multiplexed into wavelengths λ1 to λ4. When p is swapped and a signal is sent! , shows how signals C and h are swapped, respectively. Which signals are replaced can be changed by the respective control inputs.

With this configuration, it is possible to obtain an optical switch that sends m wavelength-multiplexed signals to a plurality of n input terminals to a plurality of n output terminals.

FIG. 16 is a block diagram of a device according to a sixth embodiment of the present invention. This example is also an example in which an optical switch is configured by combining a space switch and a wavelength switch.

Reference numerals 53 and 58 indicate space switches, each of which is an optical space switch that connects signals at a plurality of input terminals to any one of a plurality of output terminals. Reference numerals 54 to 57 are wavelength switches, and those described in the first or second embodiment can be used.

This has the advantage that there is no need to take a long period of time, and exchange connections can be made asynchronously. Furthermore, in the device of the present invention, there is no need to process signals at speeds exceeding the speed of input/output signals, such as highway or high-speed memory devices, thereby simplifying the device.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an apparatus according to a first embodiment of the present invention. The second threshold is a signal explanatory diagram of the device of the first embodiment. FIG. 3 is a block diagram of an apparatus according to a second embodiment of the present invention. FIG. 4 is a signal explanatory diagram of the second embodiment device. FIG. 5 is a block diagram of a device according to a third embodiment of the present invention. FIG. 6 is a signal explanatory diagram of the device of the third embodiment. FIG. 7 is a block diagram of an apparatus according to a fourth embodiment of the present invention. FIG. 8 is an explanatory diagram of signals of the device of the fourth embodiment. FIGS. 9 to 12 respectively show wavelength selection elements in which four input terminals are connected to the inputs of the first space switch 53, and each of the four outputs is connected to the wavelength switch 5.
4 to 57 are connected, the input of the second space switch 58 is connected to the output of the wavelength switches 54 to 57, and the four outputs are connected to the four output terminals. FIG. 17 is an explanatory diagram of signals of this sixth embodiment device. In this example, the signals a and p are also wavelength-multiplexed into four wavelengths λ1 to λ4, and the signals a and p are input to four input terminals.
, signal S and l, and signal C and h are exchanged and sent to the output terminal. This replacement is arbitrarily controlled by a control signal. With this configuration, it is possible to obtain an optical switch that sends m wavelength-multiplexed signals to a plurality of n input terminals to γMDn output terminals. [Effects of the Invention] As described above, according to the present invention, switching and connecting wavelength-multiplexed signals can be performed with a simple configuration. That is, the figure shows an example of the same configuration at a stage before exchanging input signals. FIG. 13 shows an example of the configuration of a wavelength conversion element. FIG. 14 is a block diagram of a device according to a fifth embodiment of the present invention. FIG. 15 is a signal explanatory diagram of the fifth embodiment device. FIG. 16 is a block diagram of an apparatus according to a sixth embodiment of the present invention. FIG. 17 is a signal explanatory diagram of the device of the sixth embodiment. 1811 to 20 are explanatory diagrams of conventional devices, respectively.

Claims (7)

[Claims] (1) One or more input terminals into which at least one inputs a wavelength-multiplexed signal of a plurality of signals of different wavelengths; one or more wavelength selection elements whose inputs are connected to this input terminal; A wavelength conversion element or a spatial switch connected to the output of the selection element, and an output terminal, and at least one of the wavelength selection element, the wavelength conversion element, and the spatial switch is variably set according to a control input. An optical switch featuring (2) The input terminal is 1, and a signal in which a plurality of signals of different wavelengths are wavelength-multiplexed is inputted to this input terminal, and a plurality of wavelength selection elements whose respective inputs are connected to this input terminal; a plurality of wavelength conversion elements respectively connected to the outputs of the wavelength selection elements; and an output terminal to which the outputs of the plurality of wavelength conversion elements are combined and connected, one or more of the wavelength selection elements being The optical switch according to claim 1, wherein the selected wavelength is variably set according to a control input. (3) The input terminal is 1, a signal in which a plurality of signals of different wavelengths are wavelength-multiplexed is inputted to this input terminal, and a plurality of wavelength selection elements each having its input connected to this input terminal; a plurality of wavelength conversion elements respectively connected to the outputs of the wavelength selection elements; and an output terminal to which the outputs of the plurality of wavelength conversion elements are combined and connected, one or more of the wavelength conversion elements being , the conversion wavelength of which is variably set according to a control input. (4) There are multiple input terminals, each input terminal receives a wavelength-multiplexed signal of multiple different wavelengths, and the input is connected to one of the multiple input terminals to select multiple wavelengths. and a plurality of output terminals connected to any of the outputs of the plurality of wavelength selection elements, and one or more of the wavelength selection elements has a selected wavelength variably set according to a control input. An optical switch according to claim (1). (5) There are multiple input terminals, each input terminal is input with a wavelength-multiplexed signal of multiple different wavelengths, and the input is connected to one of the multiple input terminals to select multiple wavelengths. a space switch connected to at least one of the outputs of the plurality of wavelength selection elements, and a plurality of output terminals to which the outputs of the space switch are connected, one or more of the wavelength selection elements comprising: The optical switch according to claim (1), wherein the selected wavelength is variably set according to the control input, and one or more of the spatial switches have input/output connections variably set according to the control input. . (6) a plurality of input terminals into which at least one of the input terminals receives a wavelength-multiplexed signal of a plurality of different wavelengths; and a plurality of wavelength selective optical switches each having its input connected to each of the plurality of input terminals. , a space switch connected to at least one of the outputs of the plurality of wavelength selective optical switches, one or more wavelength selective optical switches whose inputs are connected to the output of the spatial switch, and each of the wavelength selective optical switches. At least one of the wavelength selective optical switches has an input/output wavelength array variably set according to a control input, and the space switch has an input/output connection connected to a control input. An optical switch characterized by being variably set according to. (7) a plurality of input terminals into which at least one of the input terminals receives a wavelength-multiplexed signal of a plurality of different wavelength signals; a first spatial switch to which the plurality of input terminals are connected to the input; and the spatial switch. one or more wavelength selective switches each connected to one or more outputs of the wavelength selective switch; a second spatial switch connected to the output of this wavelength selective switch; and one or more wavelength selective switches each connected to one or more outputs of this second spatial switch. and one or more output terminals, one or more of the wavelength selective optical switches have input/output wavelength arrays variably set according to control inputs, and the space switch has input/output connections connected to the control inputs. An optical switch characterized by being variably set according to the user's needs.