JP2017046299A - Wavelength selection switchover device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wavelength selection switchover device capable of expanding the number of routes of add/drop ports by the extension of a compact and low cost unit only.SOLUTION: A wavelength selection switchover device 10 includes: a matrix optical switch 12 including (L+M) first optical switches 11 (L is an integer more of 2 or greater and M is an integer of 1 or greater), each including one external input port 8 to which a wavelength multiplex optical signal is input, and L second optical switches 14 each cross-connected to each first optical switch; L wavelength selection switches 18 in one-to-one connection with each of the second optical switch; and N third optical switches 21 (N is an integer of 2 or greater) crosses-connected with each of the L wavelength selection switches and each including one external output port 22 to output an optical signal from the L wavelength selection switches.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wavelength selective switching device used in an optical communication node, and more specifically, (L + M) (where L is an integer of L ≧ 2 and M is an integer of M ≧ 1) input path drops. Wavelength selection for selecting arbitrary N optical signals (where N is an integer of N ≧ 2) from the wavelength multiplexed optical signals input to the ports and outputting them one by one to arbitrary N local ports The present invention relates to a switching device or a wavelength selective switching device for wavelength-multiplexing and outputting N optical signals of an arbitrary wavelength, one by one input to N local ports, to an add port of an arbitrary (L + M) route. .

  Optical communication technology using an optical fiber as a transmission medium has greatly extended the transmission distance of signals, and thereby, a large-scale optical communication network has been constructed. In recent years, with the widespread use of the Internet, communication traffic has increased rapidly, and there has been an increasing demand for large capacity, high speed, high functionality, and low power consumption for communication networks. Furthermore, in preparation for an increase in communication traffic, expandability and expandability are required.

  Up to now, it has become possible to increase the transmission capacity between two points by introducing a wavelength multiplexing communication technique for simultaneously transmitting a plurality of optical signals having different wavelengths through one optical fiber transmission line.

  Furthermore, even in a relay node of a communication network, the throughput of a node is increased by using a method of performing route setting (routing) and route switching (switching) without once converting an optical signal into an electrical signal. At the same time, the power consumption of the node device can be greatly reduced.

  As an optical node system using such a system, there are an optical cross-connect (OXC) system and a reconfigurable optical add / drop multiplexing (ROADM) system.

  In the OXC system, a plurality of input side optical fiber transmission lines (hereinafter referred to as “input paths”) and a plurality of output side optical fiber transmission lines (hereinafter referred to as “output paths”) are connected to each node. In this system, an optical signal having an arbitrary wavelength among wavelength-multiplexed optical signals input from an arbitrary input path can be output to an arbitrary output path. (However, optical signals of the same wavelength input from different input routes are not simultaneously output to the same output route).

  FIG. 6 is a conceptual diagram showing a node configuration example of a conventional OXC system.

In the configuration shown in FIG. 6, D input routes 60 (# 1, # 2, # 3,... #D) (D is an integer of D ≧ 2) and D output routes 62 ( # 1, # 2, # 3,... #D) are connected to the OXC node 64. Each input path 60 (# 1, # 2, # 3,... #D) has a wavelength selective switch WSS _i (# 1, # 2) of 1 input K output (K is an integer of K ≧ 2). , # 3,... #D) are connected to each of the output paths 62 (# 1, # 2, # 3,. _o (# 1, # 2, # 3,... #D) are connected to each other.

Therefore, in the entire OXC node 64, there are D 1-input K-output wavelength selective switches WSS _i (# 1, # 2, # 3,... #D) on the input route 60 side, and the output route 62 On the side, there are D wavelength selective switches WSS _o (# 1, # 2, # 3,... #D) with K inputs and 1 outputs. The wavelength selective switch WSS _i (# 1, # 2, # 3,... #D) on the input route 60 side is connected to any K wavelength selective switches WSS _o on the output route 62 side. Cross connected.

Here, the wavelength selective switch WSS _i (# 1, # 2, # 3,... #D) receives an optical signal of an arbitrary wavelength from among the input wavelength multiplexed optical signals, which output port 66 (# 1_1). , # 1_2,..., # 1_K) can be arbitrarily set. Each output port 66 is connected to an input port 68 of a wavelength selective switch WSS _{o to which} the corresponding wavelength selective switch WSS _i is cross-connected. It is also possible to output optical signals of a plurality of wavelengths to one output port 66 at the same time.

The wavelength selective switch WSS _o (# 1, # 2, # 3,... #D) wavelength-multiplexes an optical signal of an arbitrary wavelength among optical signals input to any of the input ports 68. Can be output.

In this configuration, when K = D, it is possible to output a signal having an arbitrary wavelength among the wavelength multiplexed signals input from an arbitrary input route 60 to an arbitrary output route 62. In the case where there is no need to output an optical signal input from a certain input route 60 to a certain output route 62 (for example, the input route 60 (# 1) and the output route 62 (# 1) are the same). When it is connected to an adjacent node and it is not necessary to loop back the optical signal input from the input route 60 (# 1) to the output route 62 (# 1)), the corresponding wavelength selective switch is connected. That is, the connection between the wavelength selective switch WSS _i (# 1) and the wavelength selective switch WSS _o (# 1) can be omitted.

  Next, a multi-way ROADM system will be described. The multi-way ROADM system has a configuration in which a terminal device is connected to each node of the OXC system. In addition to being able to switch a connection route between arbitrary input / output routes, an arbitrary input / output route can be arbitrarily selected. It is a system which can connect the wavelength of this to a terminal station apparatus.

  FIG. 7 is a conceptual diagram showing a node configuration example of such a conventional multi-way ROADM system.

In other words, an example of a conventional multi-way ROADM system has D input routes 60 (# 1, # 2, # 3,... #D) and D routes as shown in FIG. The output route 62 (# 1, # 2, # 3,... #D) is connected to the ROADM node 74. Each input route 60 (# 1, # 2, # 3,... #D) has a 1-input K-output wavelength selective switch WSS _i (# 1, # 2, # 3,... #D). Are connected to each of the output paths 62 (# 1, # 2, # 3,... #D), and a wavelength selective switch WSS _o (# 1, # 2, # 3) of K input and 1 output. ,... #D) are connected to each other.

Accordingly, in the entire ROADM node 74, there are D 1-input K-output wavelength selective switches WSS _i (# 1, # 2, # 3,... #D) on the input path 60 side, and the output path 62 On the side, there are D wavelength selective switches WSS _o (# 1, # 2, # 3,... #D) with K inputs and 1 outputs.

Focusing on the wavelength selective switch (for example, wavelength selective switch WSS _i (# 1)) on the side of one input path 60, (D-1) of the K output ports 66 have different output methods. Cross-connected to the input port 68 of the wavelength selective switch WSS _o (# 2, # 3,... #D) on the path 62 side (for example, the wavelength selective switch WSS _i (# 1) and the wavelength selective switch) Like WSS _o (# 1), it is not connected to the wavelength selective switch WSS _o (# 1) connected to the output route 62 having the same number as the input route 60), and the remaining (K−D + 1) The book output port 66 is connected to the terminal station (transponder) side (drop port).

When attention is paid to the wavelength selective switch WSS _o (# 1) on the side of one output path 62 (# 1), (D−1) of the K input ports 68 include different input paths 60. Crossed to the output port 66 of the wavelength selective switch WSS _i (# 2, # 3,... #D) on the (# 2, # 3,... #D) side, and the remaining (K−D + 1) The book input port 68 is connected to an unillustrated terminal station (transponder) side (add port).

  With this configuration, it is arbitrarily selected whether to output a signal of an arbitrary wavelength from the wavelength multiplexed signals input from an arbitrary input route 60 to an arbitrary output route 62 or to be connected to the terminal station side. Is possible. Further, in addition to a signal of an arbitrary wavelength among the wavelength multiplexed signals input from an arbitrary input path 60, the optical signal input from the terminal device side is wavelength multiplexed and joined to the output path 62. (However, an optical signal having the same wavelength as the optical signal from the input path 60 is not merged from the terminal device side).

  In the configuration of FIG. 7, (K−D + 1) drop ports 66 (# 1_D,... # 1_K, # 2_D for each input route 60 (# 1, # 2, # 3,... #D). , ... # 2_K, # 3_D, ... # 3_K, #D_D, ... #D_K) and each output path 62 (# 1, # 2, # 3, ... #D) ) (K−D + 1) add ports 68 (# 1_D,... # 1_K, # 2_D,... # 2_K, # 3_D,... # 3_K, #D_D,. ) These drop ports 66 (# 1_D, ... # 1_K, # 2_D, ... # 2_K, # 3_D, ... # 3_K, ... #D_D, ... #D_K) and add port 68 (# 1_D, ... # 1_K, # 2_D, ... # 2_K, # 3_D, ... # 3_K, ... #D_D, ... #D_K), optical signals of a plurality of wavelengths are respectively received. I / O can be performed simultaneously.

  Note that the drop port 66 (# 1_D,... # 1_K, # 2_D,... # 2_K, # 3_D,... # 3_K, #D_D,... #D_K) and the add port 68 (# 1_D, ... # 1_K, # 2_D, ... # 2_K, # 3_D, ... # 3_K, #D_D, ... #D_K) and the optical transceiver of the terminal device Are connected to an optical device for separating and multiplexing the optical signals, but these are not shown in FIG.

  Next, another node configuration example of the conventional multi-way ROADM system will be described with reference to FIG.

  The configuration shown in FIG. 8 is an example in which K = D in the ROADM node 74 shown in FIG. Therefore, one drop port 66 (# 1_K, # 2_K, # 3_K,... #D_K) for each input route 60 (# 1, # 2, # 3,... #D), and each Each output route 62 (# 1, # 2, # 3,... #D) has one add port 68 (# 1_K, # 2_K, # 3_K,... #D_K), and the entire ROADM node 74 Then, there are D drop ports and D add ports.

  Furthermore, in the configuration of FIG. 8, each drop port 66 (# 1_K, # 2_K, # 3_K,... #D_K) has one 1-input N-output wavelength demultiplexer 80 (# 1, #). 2, # 3,... #D), and each output port 81 is connected to the receiving side of a transponder of a terminal device (not shown). Also, each add port 68 (# 1_K, # 2_K, # 3_K,... #D_K) has one N-input / one-output wavelength multiplexer 82 (# 1, # 2, # 3,...). #D) is connected, and each input port 83 is connected to the transmission side of a transponder of a terminal device (not shown).

  With this configuration, the wavelength-multiplexed optical signal input to the drop ports 66 (# 1_K, # 2_K, # 3_K,... #D_K) can be wavelength-separated and received by the transponder of the terminal device. Further, the optical signal transmitted from the transponder of the terminal device can be wavelength-multiplexed and output to the add port 68 (# 1_K, # 2_K, # 3_K,... #D_K).

  However, in this configuration, the wavelength of the optical signal connected to each transponder is determined by which output port 81 and input port 83 of the wavelength demultiplexer 80 and the wavelength multiplexer 82 are connected to the transponder. . In addition, the drop port 66 (# 1_K, # 2_K, # 3_K,... #D_K) and the add port 68 of the ROADM node 74 indicate which path the optical signal transmitted / received by each transponder is connected to. (# 1_K, # 2_K, # 3_K,... #D_K).

  Next, another example of the node configuration of the conventional multi-way ROADM system will be described with reference to FIG.

  In the configuration of FIG. 9, one 1-input N-output wavelength demultiplexing is provided for each drop port 66 (# 1_K, # 2_K, # 3_K,... #D_K) of the ROADM node 74 shown in FIG. Instead of the unit 80 (# 1, # 2, # 3,... #D), one 1-input N-output wavelength selective switch 90 (# 1, # 2, # 3,... #D) Are connected to each add port 68 (# 1_K, # 2_K, # 3_K,... #D_K), one N-input one-output wavelength multiplexer 82 (# 1, # 2, # 3). ,... #D), one N-input and one-output wavelength selective switch 92 (# 1, # 2, # 3,... #D) is connected.

  Each of the wavelength selective switches 90 (# 1, # 2, # 3,... #D) has N output ports 91 (for example, in the case of the wavelength selective switch 90 (# 1), the output ports 91 (# 1_1,. .., # 1_N)), and the wavelength selective switches 92 (# 1, # 2, # 3,... #D) each have N input ports 93 (for example, wavelength selective switch 92 (# 1)). , The input port 93 (# 1_1,..., # 1_N)) is connected to the transponder via these ports.

  With this configuration, the wavelength of the optical signal connected to each transponder can be arbitrarily set by the wavelength selective switch 90 on the drop port side and the wavelength selective switch 92 on the add port side (colorless function).

  However, the path to which the optical signal transmitted / received by each transponder is connected is determined by the drop port side wavelength selective switch 90 and the add port side wavelength selective switch 92 to which the transponder is connected. It depends on whether it is connected to the port 66 (# 1_K, # 2_K, # 3_K,... #D_K) and the add port 68 (# 1_K, # 2_K, # 3_K,... #D_K).

  Next, still another example of node configuration of the conventional multi-way ROADM system will be described with reference to FIG.

  In the configuration of FIG. 10, in the ROADM node 74 shown in FIG. 8, D 1-input N-output wavelengths respectively connected to the drop ports 66 (# 1_K, # 2_K, # 3_K,... #D_K). In place of the duplexer 80 (# 1, # 2, # 3,... #D), one is provided in the D drop ports 66 (# 1_K, # 2_K, # 3_K,... #D_K). Are connected to each other (in this case, D ≦ L), and each of the output ports 104 (# 1, # 2, # 3,... #N) has a variable wavelength. The filters 106 (# 1, # 2, # 3,... #N) are connected to the receiving side of the transponder. Further, in FIG. 8, D N-input one-output wavelength multiplexers 82 (# 1, # 2, #, respectively connected to each add port 68 (# 1_K, # 2_K, # 3_K,... #D_K). 3 instead of #D), one N-input L-output multicast switch 110 is connected to D add ports 68 (# 1_K, # 2_K, # 3_K,... #D_K). The output side of the transponder is connected to each input port 112 (# 1, # 2, # 3,... #N).

  Furthermore, the multicast switch 100 with L inputs and N outputs includes L optical splitters 101 (# 1, # 2, # 3,... #L) with 1 input and N outputs and N light inputs with 1 L output. It comprises switches 103 (# 1, # 2, # 3,... #L). Focusing on one optical splitter (for example, optical splitter 101 (# 1)), each output port 102 (# 1) is cross-connected to an input port of each optical switch 103. The optical signals input to the input ports 107 (# 1, # 2, # 3,... #L) of the multicast switch 100 on the drop port side correspond to the corresponding optical splitters 101 (# 1, # 2, #), respectively. 3,... #L) and N branches and distributed to each output port 102 (# 1, # 2, # 3,... #L), then each output port 102 (# 1, # 2, In # 3,... #L), the wavelength multiplexed optical signal from the desired input port 107 (# 1, # 2, # 3,... #L) is transferred to each optical switch 103 (# 1, # 2, # 3,... #N).

  In the multicast switch 100, an optical signal input to one input port (for example, the input port 107 (# 1)) can be simultaneously output to a plurality of output ports.

  Of the wavelength multiplexed optical signals output from the output ports 104 (# 1, # 2, # 3,... #N) of the optical switches 103 (# 1, # 2, # 3,... #N) Only the optical signal of the desired wavelength is selected by each wavelength variable filter 106 (# 1, # 2, # 3,... #N) and connected to the transponder.

  On the other hand, the N-input L-output multicast switch 110 includes N 1-input L-output optical switches 111 (# 1, # 2, # 3,... #N) and L N-input 1-output light. It is composed of couplers 114 (# 1, # 2, # 3,... #L). Each output port 113 of each optical switch is cross-connected to an input port 115 (# 1, # 2, # 3,... #L) of each optical coupler. This is a configuration in which the input and output of the multicast switch 100 with L input and N output are switched.

  Optical signals input from the transponders to the input ports 112 (# 1, # 2, # 3,... #N) of the multicast switch 110 are respectively associated with the corresponding optical switches 111 (# 1, # 2, # 3). ,... #N) after the desired output port 113 (# 1, # 2, # 3,... #N) is selected, the optical coupler 114 (# 1, # 2, # 3,. The optical signals from the N output ports 113 (# 1, # 2, # 3,... #N) are joined by #N), and each output port 117 (# 1, # 2, # 3, ... # N).

  With this configuration, in the case of D ≦ L, in addition to the colorless function, an optical signal dropped from any input path 60 can be received by any transponder, and from any transponder It is also possible to add the transmitted optical signal to an arbitrary output path 62 (directionless function). In addition, optical signals with the same wavelength may be added / dropped from different routes, but even in this case, different connection paths are secured between the add / drop port and the transponder. Will not collide (contentionless function).

  However, with the expansion of the network scale, the number of input / output routes connected to the ROADM node 74 increases, and when D> L, the directionless function is maintained for all input / output routes. For this purpose, the L-input N-output multicast switch 100 must be renewed to a D-input N-output multicast switch on the drop port side, and the N-input L-output multicast switch 110 must be replaced with an N-input D on the add-port side. It must be updated to an output multicast switch.

  In this regard, a multicast switch that can increase the number of input / output routes has been reported (Non-Patent Document 1).

  FIG. 11 is a conceptual diagram showing a configuration example of a conventional multicast switch capable of adding input routes.

  The multicast switch 200 shown in FIG. 11 includes L input ports 202 (# 1, # 2, # 3,... #L) and N output ports 204 (# 1, # 2, # 3,... In addition to #N), N extended input ports 206 (# 1, # 2, # 3,... #N) are provided. On the drop port side of the ROADM node 74 shown in FIG. It is used in place of the output multicast switch 100. The multicast switch 200 includes L 1-input N-output optical splitters 208 (# 1, # 2, # 3,... #L) and N (L + 1) input 1-output optical switches 210 (# 1, # 2, # 3,... #N).

  Focusing on one optical splitter (for example, 208 (# 1)), its output port 203 (# 1) is the input of each optical switch 210 (# 1, # 2, # 3,... #N). Cross-connected to the port 205 (# 1, # 2, # 3,... #N). Then, one of the (L + 1) input ports 205 of each optical switch 210 (# 1, # 2, # 3,... #N) that is not connected to the optical splitter 208 is connected to the expansion input port 206. (# 1, # 2, # 3,... #N) can be used.

  When the number of input routes 60 connected to the ROADM node 74 increases with the expansion of the network scale by using the configuration of FIG. 11, as shown in FIG. 12, the extended input port 206 (# 1 , # 2, # 3, ... #N) By adding a multicast switch 300 with L input and N output, the colorless, directionless and contentionless function without affecting the existing drop optical signal (Hereinafter referred to as the CDC function), the number of input routes 60 can be reduced to a total of 2L of L input routes 60 (#A) and L input routes 60 (#B). Can be extended.

  The multicast switch 300 includes L 1-input N-output optical splitters 308 (# 1, # 2, # 3,... #L) and N (L + 1) input 1-output optical switches 310 (# 1). , # 2, # 3,... #N).

  Further, as a multicast switch to be added to the extended input port 206 (# 1, # 2, # 3,... #N), instead of the multicast switch 300 as shown in FIG. It is also possible to use a multicast switch 200 capable of adding a route. As a result, as shown in FIG. 13, the multicast switches 200 (#A, #B) and 300 shown in FIG. 11 can be sequentially added to the extended input port 206 of each multicast switch. The number of input routes 60 is L (input route 60 (#A) only), 2L (input route 60 (#A) + input route 60 (# B)), 3L (input route 60 (#A) + input route 60 (#B) + input route 60 (#C)), and so on.

  A similar configuration can be used on the add port side of the ROADM node 74.

  FIG. 14 is a conceptual diagram showing a configuration example of a conventional multicast switch in which the number of output routes 62 can be increased.

  That is, the multicast switch 400 shown in FIG. 14 includes N input ports 402 (# 1, # 2, # 3,... #N) and L output ports 404 (# 1, # 2, # 3). ,... #L) and N extended output ports 406 (# 1, # 2, # 3,... #N), and on the add port side of the ROADM node 74 shown in FIG. It is used instead of the multicast switch 110 with N inputs and L outputs. The multicast switch 400 includes N 1-input (L + 1) output optical switches 410 (# 1, # 2, # 3,... #N) and L N-input 1-output optical couplers 412 (#). 1, # 2, # 3,... #L). Focusing on one optical switch (for example, optical switch 410 (# 1)), among the (L + 1) output ports 403 (# 1), L output ports are connected to each optical coupler 412 (# 1, # 1). Crossed to input ports 405 (# 1, # 2, # 3,... #L) of # 2, # 3,. Of the (L + 1) output ports 403 of each optical switch 410, one that is not connected to the optical coupler 412 can be used as the extended output port 406. This is a configuration in which the input and output of the multicast switch 200 on the drop port side shown in FIG. 11 are switched.

  When the number of output routes 62 connected to the ROADM node 74 increases with the expansion of the network scale by using the configuration of FIG. 14, as shown in FIG. 15, the extended output port 406 (# 1 , # 2, # 3,... #N), an N-input L-output multicast switch 500 is added to the output route while maintaining the CDC function without affecting the existing add optical signal. The number of 62 can be expanded to a total of 2L, which is a sum of L of the output route 62 (#A) and L of the output route 62 (#B).

  The multicast switch 500 includes N 1-input L-output optical switches 510 (# 1, # 2, # 3,... #N) and L N-input 1-output optical couplers 512 (# 1, #). 2, # 3,... #L).

  Further, as a multicast switch to be added to the extended output port 406 (# 1, # 2, # 3,... #N), instead of the multicast switch 500 as shown in FIG. 15, the output as described in FIG. It is also possible to use a multicast switch 400 to which the route 62 can be added. As a result, as shown in FIG. 16, the multicast switch 400 (#A, #B), 500 shown in FIG. 14 is sequentially added to each extended output port 406 of the multicast switch, thereby affecting the existing add optical signal. The number of the output routes 62 is L (only the output route 62 (#A)), 2L (the output route 62 (#A) + the output route 62 (#B) while maintaining the CDC function. )) 3L (output route 62 (#A) + output route 62 (#B) + output route 62 (#C)),...

  However, since the multicast switch is configured by using an optical splitter or an optical coupler, there is a disadvantage that there is a fundamental insertion loss associated with optical branching.

  In the configuration of the multicast switch, if a wavelength selective switch is used instead of the optical splitter and the variable wavelength filter or the optical coupler, a configuration with no principle insertion loss is possible. A wavelength selective switch is generally configured using a spatial optical system, so the device size is large and expensive compared to an optical splitter, optical coupler, or optical switch that can be integrated using a planar lightwave circuit. . However, recently, a technology for integrating multiple wavelength selective switches using a spatial optical system and a planar lightwave circuit has been reported, and a multi-input multiple-output wavelength selective switching device using the same has been reported. (Non-Patent Document 2).

  FIG. 17 is a conceptual diagram showing a configuration example of such a conventional wavelength selective switching device. This wavelength selective switching device 550 is an L input N output type as an example.

  The wavelength selection switching device 550 is used in place of the L input N output multicast switch 100 on the drop port side of the ROADM node 74 shown in FIG. This L input N output wavelength selective switching device 550 includes L 1 input N output wavelength selective switches 560 (# 1, # 2, # 3,... #L) and N L input 1 output. Optical switches 570 (# 1, # 2, # 3,... #N). For example, focusing on one wavelength selective switch 560 (# 1), it has one input port 558 (# 1) and a plurality of output ports 562 (# 1). Each output port 562 (# 1, # 2, # 3,... #N) is an input port 572 (# 1) of a different optical switch 570 (# 1, # 2, # 3,... #N). , # 2, # 3,... #N).

  With such a configuration, the signal is input from the input port 558 (# 1, # 2, # 3,... #L) to the wavelength selective switch 560 (# 1, # 2, # 3,... #L). The optical signal is transmitted to the desired input port 572 (# 1, # 2, # 3,... ##) by the wavelength selective switch 560 (# 1, # 2, # 3,... #L). N) to a desired optical switch 570 (# 1, # 2, # 3,... #N). Then, optical signals from the desired wavelength selective switches 560 (# 1, # 2, # 3,... #L) are received by the optical switches 570 (# 1, # 2, # 3,... #N). Is selected and output to the transponder via the output port 574 (# 1, # 2, # 3,... #N).

  With such a configuration, an optical signal having an arbitrary wavelength dropped from an arbitrary input path 60 can be received by an arbitrary transponder.

  A similar configuration can also be applied to the add port side of the ROADM node 74.

  FIG. 18 is a conceptual diagram showing a configuration example of a conventional wavelength selection switching device 600 applied to the add port side. This wavelength selective switching device 600 is, for example, an N input L output type.

  A wavelength selective switching device 600 shown in FIG. 18 is used in place of the multicast switch 110 with N inputs and L outputs on the add port side of the ROADM node 74 shown in FIG. This N-input L-output wavelength selective switching device 600 includes N 1-input L-output optical switches 610 (# 1, # 2, # 3,... #N) and L N-input 1-output optical switches. It comprises wavelength selective switches 620 (# 1, # 2, # 3,... #N). For example, when focusing on one optical switch such as the optical switch 610 (# 1), the optical switch 610 (# 1) includes an input port 608 (# 1) and a plurality of output ports 612 (# 1). Have. The plurality of output ports 612 (# 1) are connected to the input ports 622 (# 1, # 2, # 3,...) Of the wavelength selective switches 620 (# 1, # 2, # 3,... #L). #L).

  That is, the N-input L-output wavelength selection switching device 600 has a configuration in which the input and output of the L-input N-output wavelength selection switching device 550 on the drop port side shown in FIG.

  With such a configuration, the optical signal input from the transponder to each input port 608 (# 1, # 2, # 3,... #N) is transmitted to the corresponding optical switch 610 (# 1, # 2, ##). 3,... #N) after the desired output port 612 (# 1, # 2, # 3,... #N) is selected, the wavelength selective switch 620 (# 1, # 2, # 3, ... #L) the optical signals are combined and output from the output ports 624 (# 1, # 2, # 3,... #L).

  With such a configuration, it becomes possible to add and output an optical signal transmitted from an arbitrary transponder to an arbitrary output route 62.

  Unlike the multicast switches 100 and 110 shown in FIG. 10, the multi-input / multi-output wavelength selective switching devices 550 and 600 shown in FIGS. 17 and 18 are configured without using the optical splitter 101 or the optical coupler 114. Therefore, there is an advantage that there is no principle insertion loss accompanying optical branching.

W. J. Jiang et al., OFC 2015, Paper M3A.5. Y. Ikuma et al., OFC 2015, Paper Th5A.4.

  However, multi-input multi-output wavelength selective switching devices 500 and 600 as shown in FIGS. 17 and 18 are the same as those described in FIGS. 11 to 16, that is, similar to the multicast switches 100 and 110. When trying to expand the number of input / output routes by this method, there is a problem that the size and cost of the added unit increase.

  This problem will be described with reference to the drawings as follows.

FIG. 19 is a conceptual diagram showing a configuration example of a conventional wavelength selective switching device 700 in which the number of input paths 60 can be increased.
This wavelength selective switching device 700 includes L input ports 708 (# 1, # 2, # 3,... #L) and N output ports 722 (# 1, # 2, # 3,... #N) and N extended input ports 724 (# 1, # 2, # 3,... #N), and on the drop port side of the ROADM node 74 shown in FIG. It is used in place of the input N output multicast switch 100.

  This wavelength selective switching device 700 includes L 1-input N-output wavelength selective switches 710 (# 1, # 2, # 3,... #L) and N (L + 1) -input 1-output optical switches. 720 (# 1, # 2, # 3,... #N). For example, focusing on one wavelength selective switch such as the wavelength selective switch 710 (# 1), the N output ports 712 (# 1) of the wavelength selective switch 710 (# 1) are respectively connected to the optical switches 720 ( # 1, # 2, # 3,... #N) are cross-connected to input ports 718 (# 1, # 2, # 3,... #N). Of the (L + 1) input ports 718 (# 1) of the optical switch 720 (# 1), one input port not connected to the wavelength selective switch 710 (for example, the input port 724 (# 1)) ) Is used as an expansion input port.

  Therefore, when the number of input routes 60 connected to the ROADM node 74 increases with the expansion of the network scale, as shown in FIG. 20, the extended input ports 724 (# 1, # 2,. N), by adding an L input N output wavelength selective switching device 800, the number of input routes 60 is reduced to 2L (input method) while maintaining the CDC function without affecting the existing drop optical signal. It is possible to extend the number of paths 60 (#A) + input paths 60 (#B)).

  Further, instead of providing the extended input port 724 (# 1, # 2,... #N) in the wavelength selective switching device 700 for L input N output, as shown in FIG. 21, wavelength selective switching for L input N output is performed. An L input N output wavelength selective switching device 700 (#B) can be added to the device 700 (#A). Thus, by sequentially adding the wavelength selective switching devices 700 (#A, #B) and 800, the number of input routes 60 is maintained while maintaining the directionless function without affecting the existing drop optical signal. L (input route (#A)), 2L (input route 60 (#A) + input route 60 (#B)), 3L (input route 60 (#A) + input route 60 (# B) + input path 60 (#C)),...

  A similar configuration can also be applied to the add port side of the ROADM node 74.

  FIG. 22 is a conceptual diagram showing a configuration example of a conventional wavelength selective switching device in which the output path 62 can be added.

  That is, the wavelength selection switching device 850 shown in FIG. 22 includes N input ports 868 (# 1, # 2, # 3,... #N) and L output ports 872 (# 1, # 2, # 2). In addition to # 3,... #L), N extension output ports 874 (# 1, # 2, # 3,... #N) are provided, and the add port side of the ROADM node 74 shown in FIG. Are used in place of the multicast switch 110 with N inputs and L outputs. The wavelength selective switching device 850 includes N one-input (L + 1) output optical switches 860 (# 1, # 2, # 3,... #N) and L N-input one-output wavelength selective switches. 870 (# 1, # 2, # 3,... #L). When attention is paid to one optical switch 810 such as the optical switch 810 (# 1), for example, L output ports of the (L + 1) output ports 862 (# 1) are respectively wavelength selective switches. 820 (# 1, # 2, # 3,... #L) are cross-connected to input ports 868 (# 1, # 2, # 3,... #L). Of the (L + 1) output ports of the optical switch 860 (# 1, # 2, # 3,... #N), the wavelength selective switch 820 (# 1, # 2, # 3,. One output port not connected to L) is an extended output port 874. This is a configuration in which the input and output of the wavelength selection switching device 700 on the drop port side shown in FIG. 19 are switched.

  When the number of output routes 62 connected to the ROADM node 74 increases with the expansion of the network scale by using the configuration of FIG. 22, as shown in FIG. 23, the extended output port 874 (# 1 , # 2, # 3,... #N), by adding an N input L output wavelength selective switching device 900, while maintaining the CDC function without affecting the existing add optical signal, The number of output routes 62 can be increased to 2L.

  The wavelength selective switching device 900 includes N 1-input L-output optical switches 910 (# 1, # 2, # 3,... #N) and L N-input 1-output wavelength selective switches 920 (#). 1, # 2, # 3,... #L).

  Furthermore, as a wavelength selection switching device to be added to the extended output port 824 (# 1, # 2, # 3,... #N), a wavelength selection switching device 900 as shown in FIG. It is also possible to use the wavelength selective switching device 850 that can be added to the output path 62 as described above. Accordingly, as shown in FIG. 24, the optical switch 860 (# B1) shown in FIG. 22 is connected to each extended output port 874 (# A1, # A2,... #AN) of the wavelength selection switching device 850 (#A). , # B2,... #BN), the number of output routes 62 is reduced to L (output route 62 (#) while maintaining the CDC function without affecting the existing add optical signal. A)), 2L (output route 62 (#A) + output route 62 (#B)), 3L (output route 62 (#A) + output route 62 (#B) + output route 62 ( #C)), ... can be expanded.

  However, the configurations of FIGS. 19 to 24 are configured such that the input route 60 and the output route 62 are expanded by using a multi-input / multi-output wavelength selective switching device as an extension unit. Recently, by using a technology that integrates multiple wavelength selective switches using a spatial optical system and a planar lightwave circuit, a multiple-input multiple-output wavelength selective switching device has become a single-input multiple-output wavelength selective switching device. It is realized with the same size as.

  Nevertheless, the configuration in which the input route 60 and the output route 62 are expanded by using a multi-input / multi-output wavelength selective switching device as an extension unit is smaller than a multicast switch that can be realized only by a planar lightwave circuit. Big and expensive. Actually, when using a multicast switch, an optical amplifier for compensating the principle loss due to branching is also necessary, and although the difference in size and cost as a whole node is small, there is no principle loss, and A configuration is desired in which the number of input routes 60 and output routes 62 can be expanded by adding only smaller and lower-cost units.

  The present invention has been made in view of such a problem, and an object of the present invention is to select any N optical signals from among the wavelength multiplexed optical signals input to the drop port in the ROADM node. When outputting one by one to any N local ports, or conversely, N optical signals of any wavelength input one by one to N local ports are wavelength-multiplexed and output to any add port In order to increase the number of drop / add port routes from L to (L + M), wavelength selection switching that can increase the number of input / output routes by adding only small and inexpensive units. To provide an apparatus.

  In order to achieve the above object, a first aspect of the present invention includes the following components.

  That is, according to the first aspect of the present invention, (L + M) (L + M) first (L is an integer of 2 or more, M is an integer of 1 or more) first input terminals each receiving a wavelength multiplexed optical signal. A matrix optical switch having L optical switches, and L second optical switches cross-connected to each of the first optical switches, and one to one with each of the L second optical switches. N wavelength selective switches and N (N) each having one external output port that is cross-connected to each of the L wavelength selective switches and outputs an optical signal from the L wavelength selective switches. Is a wavelength selective switching device provided with a third optical switch.

  According to a second aspect of the present invention, there are provided M (M is an integer of 1 or more) first optical switches each having one external expansion input port to which wavelength multiplexed optical signals are input, P (P is an integer greater than or equal to L) second optical switches cross-connected to each of the optical switches, and L (L is L) each having one external basic input port to which a wavelength multiplexed optical signal is input. A total of (L + P) third optical switches and (L + P) third optical switches, each of which is connected to each of the P second optical switches on a one-to-one basis. L optical switches cross-connected to each of the optical switches, L wavelength selective switches connected to each of the L fourth optical switches on a one-to-one basis, and L wavelengths One external output that is cross-connected to each of the selective switches and outputs optical signals from the L wavelength selective switches N pieces, each having an over bets (N is an integer of 2 or more) is a wavelength selective switching device comprising: a fifth optical switch of the.

  Further, according to a third aspect of the present invention, there are provided M (M is an integer of 1 or more) first optical switches each having one external expansion input port to which wavelength multiplexed optical signals are input, wavelength multiplexed light. Each has one external basic input port to which a signal is input, and has L (L is an integer of 2 or more) second optical switches that are cross-connected to each of the first optical switches. A matrix optical switch, L wavelength selective switches connected to each of the L second optical switches on a one-to-one basis, and L wavelength selective switches cross-connected to each of the L wavelength selective switches. And a third optical switch (N is an integer of 2 or more) each having one external output port for outputting an optical signal from the wavelength selective switching device.

  The third aspect of the present invention is further limited as follows.

  That is, the matrix optical switch includes an i-th external basic input port (i is an integer satisfying 1 ≦ i ≦ L) out of L external basic input ports and M external expansion input ports. One of the total (M + 1) external input ports is the jth (j is an integer satisfying 1 ≦ j ≦ L) of the second L optical switches. It can be connected to other optical switches.

  Furthermore, a fourth aspect of the present invention provides an M number of first optical switches (M is an integer of 1 or more) each having one external extension input port to which a wavelength multiplexed optical signal is input; Each of the optical switches has L (L is an integer of 2 or more) second optical switches that are cross-connected, one external basic input port to which wavelength multiplexed optical signals are input, and L L third optical switches connected one-to-one with each of the second optical switches, and L wavelengths connected one-to-one with each of the L third optical switches N switches (N is an integer greater than or equal to 2) each having one external output port for outputting optical signals from the L wavelength selective switches, which are cross-connected to the selection switches and each of the L wavelength selective switches. And a fourth optical switch.).

  In any of the above viewpoints, when the relationship of N ≦ L is established, any N optical signals among the wavelength multiplexed signals input to (L + M) external input ports are output as N external outputs. Each port can be connected without blocking.

  That is, according to the present invention, in the ROADM node, when selecting any N optical signals among the wavelength multiplexed optical signals input to the drop port and outputting them one by one to any N local ports, or On the other hand, when N optical signals having an arbitrary wavelength inputted one by one to N local ports are wavelength-multiplexed and output to an arbitrary add port, the number of drop / add port routes is changed from L to (L + M ) Wavelengths that can expand the number of input / output paths by adding only small and inexpensive units by using optical switches that do not have wavelength selectivity instead of wavelength selective switches. A selection switching device can be realized.

FIG. 1 is a conceptual diagram showing a configuration example of a wavelength selection switching device according to the first embodiment of the present invention. FIG. 2 is a conceptual diagram showing a configuration example of a wavelength selection switching device according to the second embodiment of the present invention. FIG. 3 is a conceptual diagram showing a configuration example of a wavelength selection switching device according to the third embodiment of the present invention. FIG. 4 is a conceptual diagram showing a configuration example of a wavelength selection switching device according to the fourth embodiment of the present invention. FIG. 5 is a conceptual diagram showing an example in which the wavelength selection switching device shown in FIG. 4 is configured by a planar lightwave circuit and a spatial optical system. FIG. 6 is a conceptual diagram showing a node configuration example of a conventional OXC system. FIG. 7 is a conceptual diagram showing a node configuration example of a conventional multi-way ROADM system. FIG. 8 is a conceptual diagram showing another node configuration example of a conventional multi-way ROADM system. FIG. 9 is a conceptual diagram showing still another node configuration example of the conventional multi-way ROADM system. FIG. 10 is a conceptual diagram showing still another example of node configuration of the conventional multi-way ROADM system. FIG. 11 is a conceptual diagram showing a configuration example of a conventional multicast switch capable of adding input routes. FIG. 12 is a conceptual diagram showing another configuration example of a conventional multicast switch capable of adding input routes. FIG. 13 is a conceptual diagram showing still another configuration example of a conventional multicast switch capable of adding input routes. FIG. 14 is a conceptual diagram showing a configuration example of a conventional multicast switch capable of adding output routes. FIG. 15 is a conceptual diagram illustrating another configuration example of a conventional multicast switch capable of adding output routes. FIG. 16 is a conceptual diagram showing still another configuration example of a conventional multicast switch capable of adding output routes. FIG. 17 is a conceptual diagram illustrating a configuration example of a conventional wavelength selection switching device. FIG. 18 is a conceptual diagram showing a configuration example of a conventional wavelength selection switching device applied to the add port side. FIG. 19 is a conceptual diagram showing a configuration example of a conventional wavelength selective switching device capable of adding an input route. FIG. 20 is a conceptual diagram showing another configuration example of a conventional wavelength selective switching device capable of adding input routes. FIG. 21 is a conceptual diagram showing still another configuration example of a conventional wavelength selective switching device capable of adding input routes. FIG. 22 is a conceptual diagram showing a configuration example of a conventional wavelength selection switching device capable of adding output routes. FIG. 23 is a conceptual diagram showing another configuration example of a conventional wavelength selective switching device capable of adding output routes. FIG. 24 is a conceptual diagram showing still another configuration example of a conventional wavelength selective switching device capable of adding output routes.

  Hereinafter, a wavelength selection switching device according to an embodiment of the present invention will be described with reference to the drawings.

  The same parts as those described in the prior art are given the same numbers to avoid detailed description.

[First Embodiment]
FIG. 1 is a conceptual diagram showing a configuration example of a wavelength selection switching device according to the first embodiment of the present invention.

  That is, the wavelength selective switching device 10 according to this embodiment includes one (L + M) input L output matrix optical switch 12 and L 1 input N output wavelength selective switches 18 (# 1, # 2, #). 3,... #L) and N L-input 1-output optical switches 21 (# 1, # 2, # 3,... #N).

  Note that L, M, and N are all integers, and L ≧ 2, M ≧ 1, and N ≧ 2, and the relationship of N ≦ L is established.

  One (L + M) input L output matrix optical switch 12 further includes (L + M) one input L output optical switches 11 (# 1, # 2,..., #L, # L + 1,... , # L + M) and L (L + M) input 1-output optical switches 14 (# 1, # 2,..., #L).

  (L + M) 1-input L-output optical switches 11 (# 1, # 2,..., #L, # L + 1,..., # L + M) each have one input port 8 (# 1, # , #L, # L + 1,..., # L + M). For example, the optical switch 11 (# 1) has one input port 8 (# 1). These input ports 8 (# 1, # 2,..., #L, # L + 1,..., # L + M) are external input ports of the wavelength selection switching device 10 according to the present embodiment, and L inputs. Port 8 (# 1, # 2,..., #L) is connected to L input routes 60 (#A), and M input ports 8 (# L + 1,..., # L + M). Are connected to M input routes 60 (#B).

  All of the optical switches 11 (# 1, # 2,..., #L, # L + 1,..., # L + M) and all of the optical switches 14 (# 1, # 2,..., #L) And is cross-connected. For this reason, for example, the optical switch 11 (# 1) has L output ports 9 (# 1), and each of these L output ports 9 (# 1) has L optical switches. 14 (# 1, # 2,..., #L) are connected to any one of the input ports 13 (# 1, # 2,..., #L). Similarly, the other output ports 9 (# 2,..., #L, # L + 1,..., # L + M) have L optical switches 14 (# 1, # 2,..., #L). Are connected to any one of the input ports 13 (# 1, # 2,..., #L).

  Each of the optical switches 14 (# 1, # 2,..., #L) has (L + M) input ports 13 and one output port 15. For example, the optical switch 14 (# 1) has (L + M) input ports 13 (# 1) and one output port 15 (# 1).

  Each of the wavelength selective switches 18 (# 1, # 2,..., #L) has one input port 16 (# 1, # 2,..., #L). Each input port 16 (# 1, # 2,..., #L) is connected to the corresponding output port 15 (# 1, # 2,..., #L) on a one-to-one basis. For example, the wavelength selective switch 18 (# 1) has one input port 16 (# 1) connected one-to-one to the output port 15 (# 1), and the wavelength selective switch 18 (#L) In other words, the input port 16 (#L) is connected to the output port 15 (#L) on a one-to-one basis.

  Also, all of the L wavelength selective switches 18 (# 1, # 2,..., #L) are all of the N optical switches 21 (# 1, # 2,..., #N). Cross connected. For this purpose, each of the wavelength selective switches 18 (# 1, # 2,..., #L) has N output ports 19. For example, the wavelength selective switch 18 (# 1) has N output ports 19 (# 1), and the other wavelength selective switches 18 (# 2,..., #L) also have N output ports, respectively. 19

  N optical switches 21 (# 1, # 2,..., #N) are respectively provided with L input ports 20 (# 1, # 2,..., #N) and one output port. 22 (# 1, # 2,..., #N). For example, the optical switch 21 (# 1) has L input ports 20 (# 1) and one output port 22 (# 1).

  These output ports 22 (# 1, # 2,..., #N) are external output ports of the wavelength selection switching device 10 according to the present embodiment.

  According to the wavelength selective switching device 10 having such a configuration, when attention is paid to one optical switch 11 (# 1), each of the L output ports 9 (# 1) has different L optical switches 14. (# 1, # 2,..., #L) are connected to the input ports 13 (# 1, # 2,..., #L).

  In such a matrix optical switch 12, (L + M) input ports 13 in each of the optical switches 14 (# 1, # 2,..., #L) are all equivalent. An optical signal input to any one of the input ports can be connected to any one of the L output ports.

  1 includes (L + M) external input ports 8 (# 1, # 2,..., #L, # L + 1,..., # L + M) and N external outputs. Port 22 (# 1, # 2,..., #N), which is used in place of the multicast switch 100 on the drop port side of the ROADM node 74 shown in FIG.

  According to the wavelength selection switching device 10 according to the present embodiment, even when the number of input routes 60 (#A) connected to the ROADM node 74 increases from L as the network scale increases. The drop port of the increased input route 60 (#B) is connected to a free external input port (for example, one of the external input ports 8 (# L + 1,..., # L + M)). Therefore, it is possible to increase the number of input routes 60 from L to (L + M) without affecting the existing drop optical signal.

  Moreover, when the number of drop port paths is increased from L to (L + M), this can be realized by using the matrix optical switch 12 having no wavelength selectivity instead of the wavelength selective switch. Therefore, the number of input routes 60 can be increased from L to (L + M) by adding only small and inexpensive units.

  Further, if the input / output of the configuration of FIG. 1 is exchanged, the ROADM node 74 can be applied to the add port side.

  Even when applied to the add port side, the number of add port routes can be increased from L to (L + M) using the matrix optical switch 12 having no wavelength selectivity instead of the wavelength selective switch. Therefore, as in the case of using on the drop port side, it is possible to increase the number of output routes by adding only small and inexpensive units.

[Second Embodiment]
FIG. 2 is a conceptual diagram showing a configuration example of a wavelength selection switching device according to the second embodiment of the present invention.

  The wavelength selection switching device 30 according to the second embodiment shown in FIG. 2 is a modification of the wavelength selection switching device 10 according to the first embodiment shown in FIG. By numbering, detailed description is avoided and different points are described in detail.

  That is, the wavelength selection switching device 30 according to the present embodiment is a matrix of one (L + P) input L output instead of the matrix optical switch 12 provided in the wavelength selection switching device 10 shown in FIG. An optical switch 32 is provided. Furthermore, one M input P output matrix optical switch 34 is provided.

  Similarly to the matrix optical switch 12, the matrix optical switch 32 further includes the optical switch 11 and the optical switch 14 that are cross-connected. As in FIG. 1, the optical switch 11 has one input and L output, but the number is (L + P). Also, the number of optical switches 14 in FIG. 2 is L as in FIG. 1, but (L + P) inputs are one output.

  Similarly to the matrix optical switch 12, the matrix optical switch 34 includes an optical switch 35 and an optical switch 36 that are cross-connected. The optical switch 35 has one input P output and the number is M. The optical switch 36 has M inputs and 1 output, and the number is P.

  Each of the P optical switches 36 (# 1, # 2,... #P) is connected to the optical switch 11 (# L + 1, # L + 2,... # L + P) on a one-to-one basis.

  Note that L is an integer of L ≧ 2, P is an integer of P ≧ 1, M is an integer of M ≧ 2, and L ≦ P <M.

  In such a configuration, the L input ports 8 (# 1,..., #L) connected to the optical switch 11 (# 1,. M input ports 37 (# 1,..., #M) connected to 35 (# 1,..., #M) are external expansion ports.

  The external output ports are the output ports 22 (# 1,..., #N) as in FIG.

  Such a wavelength selection switching device 30 can also be used in place of the multicast switch 100 on the drop port side of the ROADM node 74 shown in FIG. 10, as in the first embodiment. When the number of input routes 60 connected to the ROADM node 74 becomes larger than L with the expansion of the network scale, the number of input routes 60 is reduced by adding the matrix optical switch 34. It is possible to expand from the book (input route 60 (#A)) to (L + M) books (input route 60 (#A) + input route 60 (#B)).

  Further, if the input / output of the configuration of FIG.

  As described above, according to the present embodiment, as in the first embodiment, the number of input routes and output routes can be increased by adding only a small and inexpensive unit.

[Third Embodiment]
FIG. 3 is a conceptual diagram showing a configuration example of a wavelength selection switching device according to the third embodiment of the present invention.

  Since the wavelength selection switching device 40 according to the third embodiment shown in FIG. 3 is a modification of the wavelength selection switching device 10 according to the first embodiment shown in FIG. 1, the same parts are the same here. By numbering, detailed description is avoided and different points are described in detail.

  That is, the wavelength selective switching device 40 according to this embodiment is a matrix of one (L + M) input L output instead of the matrix optical switch 12 provided in the wavelength selective switching device 10 shown in FIG. An optical switch 42 is provided.

  Further, the matrix optical switch 42 is composed of an optical switch 44 and an optical switch 46 which are cross-connected in the same manner as the matrix optical switch 12. As in FIG. 1, the optical switch 44 has one input and L output, but the number is M.

  Further, the number of optical switches 46 is L as in FIG. 1, but (M + 1) inputs and 1 output. For this reason, each of the optical switches 46 (# 1, # 2,... #L) has (M + 1) input ports 45, of which M input ports 45 are M optical switches 44. Each input port 48 is used as an external basic input port. Since there are L optical switches 46, FIG. 3 shows that a total of L input ports 48 (# 1, # 2,... #L) are used as external basic input ports.

  On the other hand, the input ports 43 (# 1, # 2,... #M) of the M 1-input L-output optical switches 44 (# 1, # 2,. Become.

  Further, the external output ports are the output ports 22 (# 1,..., #N) as in FIG.

  The wavelength selection switching device 40 having such a configuration is also provided with input ports 48 (# 1, # 2,... #L) serving as L external basic input ports and output ports serving as N external output ports. In addition to 22 (# 1, # 2,... #N), input ports 43 (# 1, # 2,... #M) serving as M external expansion input ports can be provided.

  Therefore, similarly to the first and second embodiments, it can be used instead of the multicast switch 100 on the drop port side of the ROADM node 74 shown in FIG.

  Therefore, similarly, when the number of input routes 60 connected to the ROADM node 74 increases with the expansion of the network scale, the drop ports of the increased routes are designated as external extension input ports 43 (# 1, #). 2,... #M), the input route 60 is further changed from the L routes only by the input route 60 (#A) to the input route without affecting the existing drop optical signal. By adding 60 (#B), the length can be expanded to (L + M). In addition, when expanding the number of the input paths 60, it is also possible to extend the matrix optical switch 42 while sequentially increasing the number as in FIG.

  Further, the matrix optical switch 42 shown in FIG. 3 has an advantage that the scale of the optical switch element can be reduced as compared with the matrix optical switch 12 shown in FIG. In the configuration of FIG. 3, in the matrix optical switch 42, each of the L external basic input ports, ie, the input ports 48 (# 1, # 2,... #L), is one optical switch. This is because there is a restriction that connection can be made only to 46 (# 1, # 2,... #L). For example, the input port 48 (# 1) is limited to be connected only to the optical switch 46 (# 1), and the input port 48 (#L) is connected only to the optical switch 46 (#L). It is limited to.

  Thus, in the wavelength selective switching device 40 according to the present embodiment as shown in FIG. 3, each of the L external basic input ports 48 (# 1, # 2,... #L) is an input port 48. Can be connected to only one of the L 1-input N-output wavelength selective switches 18 (# 1, # 2,... #L). However, since the optical switch 21 is located after the wavelength selective switch 18, the input ports 48 (# 1, # 2,... #L) that are external basic input ports are all connected to the external output ports 22 (# 1). , # 2,... #N) can be connected.

  Further, if the input / output of the configuration of FIG. 3 is switched, it can be used on the add port side of the ROADM node 74.

  As described above, according to the present embodiment, as in the first embodiment, the number of input routes and output routes can be increased by adding only a small and inexpensive unit.

[Fourth Embodiment]
FIG. 4 is a conceptual diagram showing a configuration example of a wavelength selection switching device according to the fourth embodiment of the present invention.

  Since the wavelength selection switching device 50 according to the fourth embodiment shown in FIG. 4 is a modification of the wavelength selection switching device 10 according to the first embodiment shown in FIG. 1, the same parts are the same here. By numbering, detailed description is avoided and different points are described in detail.

  That is, the wavelength selective switching device 50 according to the present embodiment is a matrix optical switch with one M input and L output, instead of the matrix optical switch 12 provided in the wavelength selective switching device 10 shown in FIG. 52 and L 2-input 1-output optical switches 58 (# 1, # 2,... #L).

  Further, the M-input L-output matrix optical switch 52 includes M 1-input L-output optical switches 54 (# 1, # 2,... #M) and L M-input 1-output optical switches 56. (# 1, # 2,... #L).

  In the matrix optical switch 52, the optical switches 54 (# 1, # 2,... #M) and the optical switches 56 (# 1, # 2,... #L) are the optical switches 11 in the matrix optical switch 12. And, like the optical switch 14, they are cross-connected.

  Further, each of the optical switches 54 (# 1, # 2,... #M) includes one input port 53 (# 1, # 2,... #M). These M input ports 53 (# 1, # 2,... #M) serve as external expansion input ports.

  Also, the output ports 55 (# 1, # 2,... #L) of the optical switch 56 (# 1, # 2,... #L) are respectively L number of 2-input 1-output optical switches 58 ( # 1, # 2,... #L) are connected to each of the input ports 57 (# 1, # 2,... #L) on a one-to-one basis. For example, the output port 55 (# 1) of the optical switch 56 (# 1) is connected to the input port 57 (# 1) of the optical switch 58 (# 1), and the output port 55 (#L) of the optical switch 56 (#L). #L) is connected to the input port 57 (#L) of the optical switch 58 (#L).

  The other input port 59 (# 1, # 2,... #L) of the 2-input 1-output optical switch 58 (# 1, # 2,... #L) is an external basic input port. It becomes.

  Further, the external output ports are the output ports 22 (# 1,..., #N) as in FIG.

  The wavelength selective switching device 50 having such a configuration is also provided with input ports 59 (# 1, # 2,... #L) serving as L external basic input ports and output ports serving as N external output ports. In addition to 22 (# 1, # 2,... #N), an input port 53 (# 1, # 2,... #M) as M external expansion input ports can be provided. .

  Therefore, similarly to the other embodiments, it can be used in place of the multicast switch 100 on the drop port side of the ROADM node 74 shown in FIG.

  Similarly, when the number of input routes 60 connected to the ROADM node 74 becomes larger than L as the network scale increases, the number of input routes 60 can be increased by adding matrix optical switches 52. Can be expanded from L (input route 60 (#A)) to (L + M) (input route 60 (#A) + input route 60 (#B)). In increasing the number of input routes 60, it is also possible to increase the number of input routes 60 while sequentially increasing the matrix optical switch 52, as in FIG.

  Further, if the input / output of the configuration of FIG. 4 is switched, it can be used on the ROADM node add port side.

  As described above, according to the present embodiment, as in the first embodiment, the number of input routes and output routes can be increased by adding only a small and inexpensive unit.

  In the first to fourth embodiments of the present invention described above, the integers L, M, N, and P can be arbitrarily determined according to the scale of the network and the degree of integration of optical devices. However, in order to connect any N optical signals of the wavelength multiplexed signals input to the (L + M) external input ports to the N external output ports one by one without blocking, it is an integer. L and N must satisfy N ≦ L. This is because at least N 1-input N-output wavelength selective switches 18 are required when N optical signal input paths 60 are all different.

  In the following Examples 1 to 4, a typical configuration that satisfies such a numerical relationship will be described.

  The wavelength selective switching device 10 in which L = 8, M = 8, and N = 8 in the configuration of FIG. 1 will be described.

  In order to fabricate such a wavelength selective switching device 10, all of the 16 one-input 8-output optical switches 11 and all the eight 16-input one-output optical switches 14 are obtained using a planar lightwave circuit. Are cross-connected to produce a single 16-input 8-output matrix optical switch 12. Also, all eight 8-input single-output optical switches 21 and all eight 8-input single-output optical switches 21 were cross-connected using a spatial optical system and a planar lightwave circuit.

  Next, the output ports 15 of the eight optical switches 14 were connected to the input ports 16 of the corresponding eight wavelength selective switches 18 on a one-to-one basis.

  In the wavelength selective switching device 10 thus manufactured, of the 16 input ports 8 of the 16-input 8-output matrix optical switch 12, the wavelength multiplexing of 88 channels at 50 GHz intervals input from any input port 8 is performed. It was confirmed that an optical signal having an arbitrary wavelength out of light is output from an arbitrary one of a total of eight output ports 22 from the eight optical switches 21.

  Conversely, an optical signal of any one wavelength among the 88-channel wavelength multiplexed light at intervals of 50 GHz inputted from any output port 22 among the eight output ports 22 of the eight optical switches 21 is a matrix. It was confirmed that any one of the 16 input ports 8 of the optical switch 12 was output.

  In the configuration of FIG. 2, the wavelength selection switching device 30 with L = 8, M = 16, P = 8, and N = 8 will be described.

  In order to fabricate such a wavelength selective switching device 30, as in the first embodiment, all of the 16 one-input eight-output optical switches 35 and the eight 16-input one-output are used using a planar lightwave circuit. One 16-input 8-output matrix optical switch 34 was produced by cross-connecting all of the optical switches 36 of FIG.

  Similarly to the 16-input 8-output matrix optical switch 12 of Example 1, one 16-input 8-output matrix optical switch 32 was fabricated. Further, in the same manner as in Example 1, all of the eight 1-input 8-output wavelength selective switches 18 and all of the eight 8-input 1-output optical switches 21 were cross-connected.

  Next, each output port of the eight 16-input one-output optical switches 36 was connected to one of the sixteen one-input eight-output optical switches 11.

  Further, as in the first embodiment, the output ports 15 of the eight 16-input / one-output optical switches 14 and the corresponding input ports 16 of the corresponding eight one-input 8-output wavelength selective switches 18 are connected. .

  In the wavelength selective switching device 30 manufactured in this manner, of the 16 input ports 8 provided for each of the 16 optical switches 11 included in the matrix optical switch 32, 8 corresponding to the external basic input port. Arbitrary out of 88-channel wavelength multiplexed light of 50 GHz intervals input from a total of 24 arbitrary input ports comprising 16 input ports 8 and 16 input ports 37 of 16-input 8-output matrix optical switch 34 It has been confirmed that an optical signal of one wavelength is output from any one of the eight output ports 22 from the optical switch 21.

  Conversely, an optical signal of an arbitrary wavelength of the wavelength multiplexed light of 88 channels at 50 GHz intervals inputted from any of the eight output ports 22 is sent to 16 input ports 37 of the matrix optical switch 34. , And any one of a total of 24 input ports including eight input ports 8 used as external basic input ports (not used for connection to the optical switch 36) of the matrix optical switch 32 It was confirmed that it was output from one.

  In the configuration of FIG. 3, the wavelength selection switching device 40 with L = 8, M = 8, and N = 8 will be described.

  In order to fabricate such a wavelength selective switching device 40, all eight 1-input 8-output optical switches 44 and all eight 9-input one-output optical switches 46 are obtained using a planar lightwave circuit. Were cross-connected. Further, the remaining one input port 48 of each optical switch 46, that is, a total of eight input ports 48, is a through port that is not connected to the optical switch 44. The through port is used as an external basic input port. An arbitrary path connection is possible between the eight through ports 48 and the eight nine-input one-output optical switches 46. When no path is set, the j-th (j is 1 ≦ j ≦ The optical signal input to the input port 48 of an integer of 8 is connected to the j th through port.

  In addition, one input port 43 of each optical switch 44, that is, a total of eight input ports 43 is used as an external expansion input port.

  Thus, one 16-input 8-output matrix optical switch 42 was produced.

  Next, in the same manner as in the first embodiment, all of the eight 1-input 8-output wavelength selective switches 18 and all of the eight 8 × 1 optical switches 21 are used by using a spatial optical system and a planar lightwave circuit. Cross connected.

  Then, each output port 47 of each optical switch 46 is connected to each input port 16 of the corresponding wavelength selective switch 18 on a one-to-one basis.

  In the wavelength selective switching device 40 thus fabricated, an optical signal having an arbitrary wavelength among the 88-channel wavelength multiplexed light at intervals of 50 GHz input from the 16 arbitrary input ports 43 and 48 of the matrix optical switch 42. Is output from any one of the eight output ports 22 from the optical switch 21.

  On the other hand, an optical signal of one arbitrary wavelength among the wavelength multiplexed light of 88 channels at intervals of 50 GHz input from any one of the eight output ports 22 is input from the input ports 43 and 48. It was confirmed that an arbitrary one was output.

  In the configuration of FIG. 4, the wavelength selection switching device 50 in which L = 8, M = 8, and N = 8 will be described.

  In order to fabricate such a wavelength selective switching device 50, all eight 8-input single-output optical switches 56 and all eight 8-input single-output optical switches 56 are obtained using a planar lightwave circuit. Are cross-connected to form one 8-input 8-output matrix optical switch 52. Further, the output ports 55 of the eight 8-input 1-output optical switches 56 are connected one-to-one with the corresponding input ports 57 of the corresponding 8-input 1-output optical switches 58.

  Next, in the same manner as in the first embodiment, all of the eight 1-input 8-output wavelength selective switches 18 and all of the eight 8 × 1 optical switches 21 are used by using a spatial optical system and a planar lightwave circuit. Cross connected.

  Further, the output ports of the eight 2-input 1-output optical switches 58 are connected one-to-one with the input ports 16 of the corresponding eight 1-input 8-output wavelength selective switches 18.

  FIG. 5 is a conceptual diagram showing an example in which the wavelength selection switching device 50 manufactured as described above is configured by a planar lightwave circuit 1301 and a spatial optical system 1302.

  In the wavelength selective switching device 1300 as shown in FIG. 5, eight 2-input 1-output optical switches 1331 to 1338, 9 spatial beam converters 1340 to 1348, and 8 8-inputs on the planar lightwave circuit 1301. One-output optical switches 1381 to 1388 are integrated.

  The spatial optical system 1302 includes a diffraction grating 1351, a lens 1361, and an optical deflection switch array 1371. The optical switch 1331 selects one of the optical signals input from the input ports 1311 and 1321.

  The optical switch 1332 selects one of the optical signals input from the input ports 1312 and 1322.

  Similarly, the other optical switches 1333,..., 1338 select either one of the optical signals input from the corresponding two input ports.

  The optical signal selected by the optical switch 1331 is emitted from the spatial beam converter 1340 to the spatial optical system 1302, demultiplexed into each wavelength in the direction perpendicular to the paper surface by the diffraction grating 1351, and then the optical deflection switch array 1371 by the lens 1361. Focused on top.

  The optical signal reflected by the optical deflection switch array 1371 passes through the lens 1361 again, is multiplexed by the diffraction grating 1351, and returns to the planar lightwave circuit 1301, but by controlling the reflection angle by the optical deflection switch array 1371, space Any one of the beam converters 1341-1348 is selected. At this time, the incident angle to the spatial beam converters 1341 to 1348 is the same as that emitted from the spatial beam converter 1340. With this configuration, an optical signal having an arbitrary wavelength among optical signals selected by the optical switch 1331 can be connected to any one of the spatial beam converters 1341 to 1348.

  Similarly, the optical signal selected by the optical switch 1332 is emitted from the spatial beam converter 1340 to the spatial optical system 1302. At this time, the spatial beam conversion is performed at an angle different from that of the optical signal selected by the optical switch 1331. The light is emitted from the container 1340. As a result, a position different from the optical signal selected by the optical switch 1331 when the light is demultiplexed into each wavelength in the direction perpendicular to the paper surface by the diffraction grating 1351 and then condensed on the optical deflection switch array 1371 by the lens 1361. It is focused on.

  The optical signal reflected by the optical deflection switch array 1371 passes through the lens 1361 again, is multiplexed by the diffraction grating 1351, and returns to the planar lightwave circuit 1301, but by controlling the reflection angle by the optical deflection switch array 1371, Any one of the spatial beam converters 1341-1348 is selected. At this time, since the incident angle to the spatial beam converters 1341 to 1348 is the same as that emitted from the spatial beam converter 1340, it is incident at an angle different from the optical signal selected by the optical switch 1331. .

  With this configuration, an optical signal having an arbitrary wavelength among optical signals selected by the optical switch 1332 can be selected from any one of the spatial beam converters 1341 to 1348 independently of the optical signal selected by the optical switch 1331. Can be connected to one of these.

  Hereinafter, similarly, an optical signal having an arbitrary wavelength among optical signals selected by the optical switches 1333,..., 1338 is separated from the optical signals selected by other optical switches. It can be connected to any one of the beam converters 1341-1348.

  In this way, from the spatial beam converter 1341, an optical signal having an arbitrary wavelength among the optical signals selected by the optical switches 1331 to 1338 is output from different optical waveguides, but has 8 inputs and 1 output. Any one of them can be selected and output from the output port 1391 by the optical switch 1381.

  Similarly, from other spatial beam converters 1342,..., 1348, optical signals having an arbitrary wavelength among optical signals selected by the optical switches 1331 to 1338 are output from different optical waveguides. However, any one of them can be selected and output from the output ports 1392,..., 1398 by the corresponding 8-input 1-output optical switches 1382,.

  In the wavelength selective switching device 1300, an 8-input 8-output matrix optical switch (not shown) is connected to one of the two core ports of the optical switches 1331 to 1338.

  In the 16-input 8-output wavelength selective switching device 1300 configured as described above, the total number of optical switches 1331-1338 (which is not connected to the 8-input 8-output matrix optical switch among the two core ports) An optical signal of an arbitrary wavelength among 88-channel wavelength multiplexed light of 50 GHz intervals input from a total of 16 arbitrary ports consisting of 8 and 8 from an 8-input 8-output matrix optical switch (not shown), It was confirmed that any one of the 8 ports on the optical switch side with 8 inputs and 1 output can be output.

  Conversely, an optical signal of any one wavelength in 88 channels at intervals of 50 GHz inputted from 8 arbitrary ports on the optical switch side with 8 inputs and 1 output is selected from any of the 16 ports described above. It was confirmed that it was output from one line.

  As described above, the wavelength selective switching devices according to Examples 1 to 4, which are specific configuration examples of the first to fourth embodiments, function correctly even when disposed on the drop port side or the add port side. To do.

  The wavelength selective switching device according to the present invention as described above is not limited, but uses a technique for integrating multiple wavelength selective switching devices in a small size using a spatial optical system and a planar lightwave circuit. Is desirable.

  In addition, the optical switch with no wavelength selectivity that constitutes the extension unit has good compatibility with optical fibers, low insertion loss, low theoretical polarization dependence, and physical construction materials. A thermo-optic switch based on a quartz-based optical waveguide, which is chemically stable and excellent in reliability, has the highest practicality and is suitable for the implementation of the present invention.

  Of course, the present invention is not limited to these, and the present invention can be implemented by various modifications as long as they do not depart from the gist of the present invention.

  In short, the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

8 input port, 9 output port, 10 wavelength selective switching device, 11 optical switch, 12 matrix optical switch, 13 input port, 14 optical switch, 15 output port, 16 input port, 18 wavelength selective switch, 19 output port, 20 input Port, 21 optical switch, 22 output port, 30 wavelength selective switching device, 32 matrix optical switch, 34 matrix optical switch, 35 optical switch, 36 optical switch, 37 input port, 40 wavelength selective switching device, 42 matrix optical switch, 43 Input port, 44 optical switch, 45 input port, 46 optical switch, 47 output port, 48 input port, 50 wavelength selection switching device, 52 matrix optical switch, 53 input port, 54 optical switch, 55 output port, 56 optical switch, 7 input port, 58 optical switch, 59 input port, 60 input route, 62 output route, 64 OXC node, 66 output port, 68 input port, 74 ROADM node, 80 wavelength demultiplexer, 81 output port, 82 wavelength Multiplexer, 83 input port, 90 wavelength selection switch, 91 output port, 92 wavelength selection switch, 93 input port, 100 multicast switch, 101 optical splitter, 102 output port, 103 optical switch, 104 output port, 106 wavelength tunable filter 107 input port, 110 multicast switch, 111 optical switch, 112 input port, 113 output port, 114 optical coupler, 115 input port, 117 output port, 200 multicast switch, 202 input port, 203 Output port, 204 output port, 205 input port, 206 expansion input port, 208 optical splitter, 210 optical switch, 300 multicast switch, 308 optical splitter, 310 optical switch, 400 multicast switch, 402 input port, 403 output port, 404 output Port, 405 input port, 406 extended output port, 410 optical switch, 412 optical coupler, 500 multicast switch, 510 optical switch, 512 optical coupler, 550 wavelength selective switching device, 558 input port, 560 wavelength selective switch, 562 output port, 570 optical switch, 572 input port, 574 output port, 600 wavelength selection switching device, 608 input port, 610 optical switch, 612 output port, 620 wavelength Selection switch, 622 input port, 624 output port, 700 wavelength selection switching device, 708 input port, 710 wavelength selection switch, 712 output port, 718 input port, 720 optical switch, 722 output ports, 724 expansion input port, 800 Wavelength selective switching device, 810 optical switch, 820 wavelength selective switch, 824 extended output port, 850 Wavelength selective switching device, 860 optical switch, 862 output port, 868 input port, 870 Wavelength selective switch, 872 output port, 874 extended output port 900 wavelength selective switching device, 910 optical switch, 920 wavelength selective switch, 1300 wavelength selective switching device, 1301 planar lightwave circuit, 1302 spatial optical system, 1311 input port, 1312 input port, 1331 Switch, 1332 Optical switch, 1333 Optical switch, 1334 Optical switch, 1335 Optical switch, 1336 Optical switch, 1337 Optical switch, 1338 Optical switch, 1340 Spatial beam converter, 1341 Spatial beam converter, 1342 Spatial beam converter, 1343 Spatial Beam converter, 1344 Spatial beam converter, 1345 Spatial beam converter, 1346 Spatial beam converter, 1347 Spatial beam converter, 1348 Spatial beam converter, 1351 Diffraction grating, 1361 Lens, 1371 Optical deflection switch array, 1381 Optical switch , 1382 optical switch, 1383 optical switch, 1384 optical switch, 1385 optical switch, 1386 optical switch, 1387 optical switch, 1388 optical switch, 1391 output port, 1392 output port, 1398 output port

Claims (6)

(L + M) first optical switches (L + M) each having one external input port to which a wavelength multiplexed optical signal is input, and the first optical switch. A matrix optical switch having L second optical switches cross-connected with each of
L wavelength selective switches connected in a one-to-one relationship with each of the L second optical switches;
N (N is an integer of 2 or more) each having one external output port that is cross-connected to each of the L wavelength selective switches and outputs an optical signal from the L wavelength selective switches. A third optical switch;
A wavelength selective switching device comprising: M (M is an integer of 1 or more) first optical switches each having one external expansion input port to which wavelength multiplexed optical signals are input;
P (P is an integer greater than or equal to L) second optical switches cross-connected to each of the first optical switches;
L (L is an integer of 2 or more) each having one external basic input port to which wavelength multiplexed optical signals are input, and P connected to each of the P second optical switches in a one-to-one relationship. A total of (L + P) third optical switches,
L fourth optical switches cross-connected to each of the (L + P) third optical switches;
L wavelength selective switches connected in a one-to-one relationship with each of the L fourth optical switches;
N (N is an integer of 2 or more) each having one external output port that is cross-connected to each of the L wavelength selective switches and outputs an optical signal from the L wavelength selective switches. A fifth optical switch;
A wavelength selective switching device comprising: M (M is an integer of 1 or more) first optical switches each having one external expansion input port to which wavelength multiplexed optical signals are input, and one external basic input to which wavelength multiplexed optical signals are input A matrix optical switch having L (L is an integer of 2 or more) second optical switches each having a port and being cross-connected to each of the first optical switches;
L wavelength selective switches connected in a one-to-one relationship with each of the L second optical switches;
N (N is an integer of 2 or more) each having one external output port that is cross-connected to each of the L wavelength selective switches and outputs an optical signal from the L wavelength selective switches. A third optical switch;
A wavelength selective switching device comprising: The matrix optical switch includes an i-th external basic input port (i is an integer satisfying 1 ≦ i ≦ L) among L external basic input ports and M external expansion input ports. One external input port of the total (M + 1) external input ports is connected to the jth (j is an integer of 1 ≦ j ≦ L) second of the L second optical switches. Connectable with optical switch
The wavelength selective switching device according to claim 3. M (M is an integer of 1 or more) first optical switches each having one external expansion input port to which wavelength multiplexed optical signals are input;
L (L is an integer of 2 or more) second optical switches cross-connected to each of the first optical switches;
L third optical switches each having one external basic input port to which a wavelength multiplexed optical signal is input and connected to each of the L second optical switches on a one-to-one basis; ,
L wavelength selective switches connected in a one-to-one relationship with each of the L third optical switches;
N (N is an integer of 2 or more) each having one external output port that is cross-connected to each of the L wavelength selective switches and outputs an optical signal from the L wavelength selective switches. A fourth optical switch;
A wavelength selective switching device comprising:   The wavelength selective switching device according to claim 1, wherein N ≦ L.