JP2017055169A - Optical switch device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical switch device in which the number of I/O ports can be increased, without reducing power transmittance.SOLUTION: An optical switch device 1 includes M×N wavelength variable transmitters 201 connected with the input ports thereof, and sending the signals from the input ports with a desired signal wavelength, M×N 1 input/M output type optical switches 202 connected with respective wavelength variable transmitters, M×N M input/1 output type wavelength selection switches 203 connected with any one of the optical switches, and M N input/N output type wavelength routing devices 204 connected with any one of the wavelength selection switches. Respective optical switches and wavelength selection switches are interconnected to constitute N sets of M input/M output distributed merged optical switches 205, and respective distributed merged optical switches and wavelength routing devices are connected in combination capable of routing all I/O systems.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an optical switch device used for an optical communication network.

  With the spread of the Internet, the demand for data communication networks is increasing rapidly. In particular, practical use of an optical switch having an extremely large number of ports is required in a network application of a local area network (LAN) system. In response to such a demand, the number of ports of optical switches that are actually put into practical use is only about several tens.

  In recent years, N-input N-output devices with wavelength-variable transmitters, M-input M-output split-and-flow (DC) delivery and couple (DC) optical switches, and wavelength input / output characteristics equivalent to arrayed waveguide gratings By using (M), a highly expandable optical switch device having a maximum of M × N input / output ports has been proposed (Non-patent Document 1).

  FIG. 1 is a diagram showing the configuration of such an optical switch device 100. This conventional optical switch device 100 includes M × N variable wavelength transmitters 101 that transmit an input signal at a desired signal wavelength, N M-input M-output combined flow type optical switches 105, and M pieces. N-input N-output type arrayed waveguide grating (AWG) 104. M and N are integers of 2 or more. In FIG. 1, M = 3 and N = 4.

  Each of the N split-flow optical switches 105 is configured to output input light to a desired arrayed waveguide diffraction grating 104 by switching, and M 1-input M-output optical switches 102; M M-input single-output optical couplers 103 are provided.

  In the following description, the description common to each of the M × N wavelength tunable transmitters 101 is referred to as the wavelength tunable transmitter 101, and the description common to each of the M × N optical switches 102 is the optical switch. Reference numeral 102 denotes the optical coupler 103 in the description common to each of the M × N optical couplers 103. Further, the description common to each of the M arrayed waveguide diffraction gratings 104 is referred to as the arrayed waveguide diffraction grating 104, and the description common to each of the N number of mixed flow type optical switches 105 is used. Refer to as

  In each of the four split-flow optical switches 105, the M optical switches 102 and the M optical couplers 103 are connected in a full mesh. Each of the three optical couplers 103 belonging to the same split-flow optical switch 105 is connected to a different arrayed waveguide diffraction grating 104.

  The optical switch device 100 to which the optical signal is input transmits the signal to the optical switch 102 with the wavelength variable transmitter 101 having an appropriate wavelength. The optical switch 102 outputs the signal to a desired optical coupler 103 so that the signal can be output to a desired output port of the optical switch device 100. A signal from the optical coupler 103 is input to the arrayed waveguide grating 104 and output to an output port determined by the input port and the signal wavelength. As described above, in the optical switch device, by transmitting a signal having a predetermined wavelength from the wavelength variable transmitter 101 and appropriately setting (selecting) the output port of the optical switch 102, the signal is transmitted to a desired port. Can be sent to.

  In the conventional optical switch device 100, a maximum of 3 (= M) wavelength tunable transmitters 101 may simultaneously send signals to one port of the same arrayed waveguide grating 104. It is necessary to be able to join signals transmitted from the wavelength tunable transmitter 101. However, when the signals transmitted from all the wavelength tunable transmitters 101 are combined to be simultaneously transmitted to the same arrayed waveguide grating 104, the port destination to which those signals are finally output differs. Therefore, the wavelengths of the signals are all different.

  In the conventional optical switch device 100, a signal is transmitted via the same wiring between the optical coupler 103 and the arrayed waveguide grating 104. However, as described above, the wavelength of the signal is different. It is possible to output a signal without interference.

T. Niwa, H. Hasegawa, K. Sato, “A 270 × 270 optical cross-connect switch utilizing wavelength routing with cascaded AWGs,” Optical Fiber Communication Conference and Exposition and the National Fiber Optic Engineers Conference (OFC / NFOEC) 2013, OTh1A.3 (2013).

  In the conventional optical switch device, an optical coupler with M inputs and 1 output is used. In general, however, the optical coupler has a reduced power transmittance and a loss due to the number of branches. For example, in the case of an optical coupler with M inputs and 1 output, the power transmittance is 1 / M, and as a result, the power of the signal output from the optical switch device is also reduced.

  Although the power of the output signal of the optical switch device needs to be a certain value or more, when the number of branches of the optical coupler is increased, the power of the output signal can be smaller than the certain value due to loss of power transmittance. . For this reason, the conventional optical switch device has a problem that the number of branches of the optical coupler is limited, and as a result, the number of input / output ports of the merging / distributing optical switch device is also limited.

  The present invention has been made under such circumstances, and an object of the present invention is to provide an optical switch device capable of increasing the number of input / output ports as compared with the conventional one without reducing the power transmittance. .

  An invention for solving the above-described problems is an optical switch device having M × N inputs M × N outputs (both M and N are integers of 2 or more), which is connected to an input port of the optical switch device, and the input M × N wavelength tunable transmitters for transmitting signals from ports at a desired signal wavelength; M × N 1-input M output optical switches connected to the wavelength tunable transmitters; M × N M-input single-output wavelength selective switches connected to any one of the switches, and M N-input N-output wavelength routing devices connected to any of the wavelength selective switches. In each of the optical switch and the wavelength selective switch, N sets of M-input M-output split-flow switches are configured by interconnecting the optical switches and the wavelength-selective switches. Each of the wavelength routing devices is connected to each other in a combination that allows route selection of all input / output systems.

  An invention for solving the above-mentioned problem is an optical switch device of M × N input M × N output (both M and N are integers of 2 or more), which is connected to an input port of the optical switch device, M × N variable wavelength transmitters for transmitting signals from the input port at a desired signal wavelength, and M × N 1-input A-output first optical switch connected to each of the variable wavelength transmitters A (A is an integer of 2 or more) × M × N one-input (M / A) output second optical switch connected to any one of the first optical switches, and the second optical switch M × N M input (M / A) output type wavelength selective switches connected to any of the above, and M N input N output type wavelength routing devices connected to any of the wavelength selective switches And the second optical switch and the wavelength selection switch. In each of the first and second optical switches, each of the second optical switches and each wavelength selective switch has an M × (M / A) output split-flow type switch configured by an A × N combination. Each of the routing devices is connected to each other in a combination that allows route selection of all input / output systems.

  According to the present invention, the number of input / output ports can be increased more than before without reducing the power transmittance.

It is a figure which shows the structure of the conventional optical switch apparatus. It is a figure which shows the structural example of the optical switch apparatus in 1st Embodiment of this invention. It is a figure which shows the structural example of the optical switch apparatus in 2nd Embodiment of this invention.

<First Embodiment>
Hereinafter, the optical switch device 1 according to the first embodiment will be described. The optical switch device 1 of this embodiment has M × N inputs and M × N outputs. M and N are integers of 2 or more.

  FIG. 2 is a schematic diagram illustrating a configuration example of the optical switch device 1 according to the first embodiment. In FIG. 2, as an example, an optical switch device 1 having 12 inputs and 12 outputs and M = 4 and N = 3 is shown. The numbers of M and N are not limited to this example and may be changed.

  As shown in FIG. 2, the optical switch device 1 includes twelve variable wavelength transmitters 201, twelve one-input four-output optical switches 202, twelve four-input one-output wavelength selective switches 203, And four three-input three-output wavelength routing devices 204.

  In this embodiment, twelve optical switches 202 and twelve wavelength selective switches 203 are a set of four, and three split-flow optical switches 205 are configured.

  In the following description of the present embodiment, the description common to each of the twelve variable wavelength transmitters 201 is referred to as the variable wavelength transmitter 201, and the common description of each of the twelve optical switches 202 is referred to as the optical switch 202. In the description common to each of the twelve wavelength selective switches 203, the wavelength selective switch 203 is referred to. Further, a description common to each of the four wavelength routing devices 204 is referred to as a wavelength routing device 204, and a description common to each of the three split-flow optical switches 205 is referred to as a split-flow optical switch 205.

  The wavelength tunable transmitter 101 is connected corresponding to the input ports In1, In2,..., In12 of the optical switch device 1, converts a signal from the input port to a desired wavelength, and sends the signal to the optical switch 202. .

  The optical switch 202 is configured with one input and four outputs, and the wavelength selective switch 203 is configured with four inputs and one output. A split-flow optical switch 205 including four optical switches 202 and four wavelength selective switches 203 outputs input light to a desired arrayed waveguide grating 104 by switching. All or one or more of the three split-flow optical switches 205 may be modularized. The method of fabricating the module is described in, for example, the literature (Yuichiro Ikuma, Kenya Suzuki, Naru Nemoto, Etsu Hashimoto, Osamu Moriwaki, and Tetsuo Takahashi, “8 × 24 Wavelength Selective Switch for Low-loss Transponder Aggregator,” Proceedings of Optical Fiber Communication. Conference 2015, Th5A.4).

  In the same split flow optical switch 205, the optical switch 202 and the wavelength selective switch 203 are fully meshed so that the route selection to all four wavelength selective switches 203 constituting the same split flow optical switch 205 can be performed. It is connected.

  The split-flow optical switch 205 is connected to all the wavelength routing devices 204.

  The wavelength selective switch 203 is a WSS (Wavelength Selective Switch), and is configured to select one input port for each signal wavelength and couple the input port to the output port. In the case of WSS, the power transmittance can be maintained at a constant value regardless of the number of input ports.

  The wavelength routing device 204 is, for example, an arrayed waveguide grating (AWG), and is configured to determine an output port selected based on an input port and a signal wavelength. The output port of the wavelength routing device 204 is connected corresponding to the output ports Out1, Out2,..., Out12 of the optical switch device 1.

[Outline of path setting in optical switch device]
An outline of path setting realized by the optical switch device 1 will be described again with reference to FIG.

  In the optical switch device 1, paths from the input ports In1, In2, ..., In12 to the output ports Out1, Out2, ..., Out12 are set, but the paths from each input port to each output port are: There are not multiple, but only one.

  When setting the path, first, the wavelength of the signal to be converted by the wavelength tunable transmitter 201 is set so that the signal transmitted by the wavelength tunable transmitter 201 corresponds to the input port and output port of the wavelength routing device 204. .

  Next, the output port of the optical switch 202 is set so that the signal can pass through the optical switch 202. Further, the input port of the wavelength selective switch 203 is coupled to the output port of the wavelength selective switch 203 for the wavelength transmitted from the wavelength tunable transmitter 201 so that the signal can be passed through the wavelength selective switch 203. As a result, the signal of the wavelength converted by the wavelength tunable transmitter 201 is sent to the desired output ports Out1, Out2, (desired to output signals) via the desired optical switch 202, the wavelength selective switch 203, and the wavelength routing device 204. ..., output from any of Out12.

  As described above, according to the optical switch device 1 of the present embodiment, the signal from the wavelength tunable transmitter 201 is sent to the wavelength routing device 204 via the optical switch 202 and the wavelength selective switch 203 and output port. Output from any of Out1, Out2,..., Out12. Here, unlike the optical coupler, the wavelength selective switch 203 transmits the signal to a desired wavelength routing device 204 according to the wavelength of the signal while maintaining the power transmittance at a constant value regardless of the number of input ports. Therefore, even when the number of input ports is increased, it is possible to achieve a power transmittance of a certain level or more. In this respect, according to this optical switch device 1, it is possible to configure a large-scale optical switch device having a large number of ports as compared with a conventional optical switch device including an optical coupler.

Second Embodiment
The optical switch device 1A according to the second embodiment will be described below with reference to FIG.

  FIG. 3 is a schematic diagram illustrating a configuration example of the optical switch device 1A according to the second embodiment.

  In the optical switch device 1 of the first embodiment, (M × N) 1-input M-output optical switches 202 are provided, but this configuration is not necessarily required. The optical switch device 1A of the present embodiment realizes M × N inputs and M × N outputs (M and N are integers of 2 or more), as in the first embodiment. However, instead of (M × N) 1-input M-output optical switches 202, (M × N) 1-input A-output optical switches 302 and (A × M × N) 1-input (M / A) output type optical switch 303 (A is an integer of 2 or more).

  In FIG. 3, as an example, an optical switch device 1 having 12 inputs and 12 outputs and M = 4, N = 3, and A = 2 is shown. The numbers of M, N, and A are not limited to this example, and may be changed.

  In FIG. 3, an optical switch device 1A includes 12 variable wavelength transmitters 301, 12 1-input 2-output optical switches 302, 24 1-input 2-output optical switches 303, and 4-input 1-output. Type wavelength selective switch 304 and four three-input three-output type wavelength routing devices 305.

  One set of four optical switches 302 is configured as a module 307. Further, a combination flow type optical switch 306 is configured by combining four optical switches 303 and two wavelength selective switches 304. In this embodiment, the split-flow optical switch 306 can be configured as a module in the same manner as the split-flow optical switch 205 shown in FIG.

  In the following description of the present embodiment, the description common to each of the twelve variable wavelength transmitters 301 is referred to as the variable wavelength transmitter 301, and the common description of each of the twelve optical switches 302 is referred to as the optical switch 302. Reference is made to the optical switch 303 in the description common to each of the 24 optical switches 303. Further, the description common to each of the twelve wavelength selective switches 304 is referred to as the wavelength selective switch 304, and the common description to each of the four wavelength routing apparatuses 305 is referred to as the wavelength routing apparatus 305.

  The wavelength variable transmitter 301, the wavelength selective switch 304, and the wavelength routing device 305 in FIG. 3 are the same as the wavelength variable transmitter 201, the wavelength selective switch 203, and the wavelength routing device 204 in FIG.

  4 (= M) optical switches 303 and 2 (= A) split-combination-type optical switches 306 are made into one set, and each optical switch 303 and each split-combination-type optical switch 306 are realized in all combinations. Are connected with full mesh.

  In the optical switch device 1A, the signals from the input ports In1, In2,..., In12 of the optical switch device 1 are converted to a desired wavelength by the wavelength variable transmitter 301 and transmitted to the optical switch 302. Further, the optical switch It is sent to 303. A signal from the optical switch 303 is output from the output ports Out1, Out2,..., Out12 via the wavelength selective switch 304 and the wavelength routing device 305.

  As described above, even if configured as the optical switch device 1A of the present embodiment, the wavelength selective switch 304 is different from the optical coupler in the same manner as in the first embodiment, and the power transmittance regardless of the number of input ports. Since the signal can be transmitted to a desired output port while maintaining a constant value, it is possible to achieve a power transmittance of a certain level or more. Therefore, a large-scale optical switch device 1A having a large number of ports can be configured as compared with a conventional optical switch device including an optical coupler.

  Furthermore, according to the optical switch device 1A, instead of the 1-input M-output optical switch 202 of the first embodiment, (M × N) 1-input A-output optical switches 302 and (A × M × N) one single-input (M / A) output type optical switch 303, so that the number of wavelength selection switches 304 in the split-flow type optical switch 306 is equal to that of the split-flow type optical switch 205 of the first embodiment. 2 less than what is shown. Since the number of wavelength selective switches having complicated functions is reduced by 2, the optical switch device 1A can be easily manufactured. In addition, an optical switch device having a larger number of ports than that of the first embodiment can be realized.

  Although each embodiment has been described in detail, the number of input / output ports of the specific optical switch device 1, 1 </ b> A is not limited to each embodiment, and design changes and the like within the scope of the present invention are also possible. included.

1,1A Optical switch device 201,301 Variable wavelength transmitter
202, 302, 303 Optical switch 203, 304 Wavelength selective switch 204, 305 Wavelength routing device

Claims (3)

An optical switch device having M × N inputs M × N outputs (both M and N are natural numbers),
M × N variable wavelength transmitters that are connected to the input port of the optical switch device and transmit a signal from the input port at a desired signal wavelength;
M × N 1-input M-output optical switches connected to each of the wavelength tunable transmitters;
M × N M-input single-output wavelength selective switches connected to any of the optical switches;
And M N-input N-output wavelength routing devices connected to any of the wavelength selective switches,
Each of the optical switch and the wavelength selective switch includes N sets of M-input and M-output split flow type switches by interconnection of each optical switch and each wavelength selective switch.
The split-flow switch and the wavelength routing device are connected to each other in a combination that allows route selection of all input / output systems. An M × N input M × N output optical switch device,
M × N variable wavelength transmitters that are connected to the input port of the optical switch device and transmit a signal from the input port at a desired signal wavelength;
M × N 1-input A-output first optical switch connected to each of the tunable transmitters;
A (A is a natural number) × M × N one-input (M / A) output second optical switch connected to any of the first optical switches;
M × N M input (M / A) output type wavelength selective switches connected to any of the second optical switches;
And M N-input N-output wavelength routing devices connected to any of the wavelength selective switches,
Each of the second optical switch and the wavelength selective switch has an M × (M / A) output split flow type switch configured by A × N sets by interconnection of each second optical switch and each wavelength selective switch. And
The split-flow switch and the wavelength routing device are connected to each other in a combination that allows route selection of all input / output systems.   The optical switch device according to claim 1, wherein the split-flow switch is configured as a module.