JP5850313B2 - Wavelength group optical path cross-connect equipment - Google Patents

Description

  The present invention relates to an optical path cross-connect device that is provided in an optical network and can output an input optical signal from a desired output port and perform termination processing.

  For example, an optical signal having a predetermined bit rate on the order of GHz to THz is combined for each of a plurality of wavelengths respectively corresponding to a plurality of wavelength channels (wave channels or light paths) divided every 100 GHz of a predetermined communication wavelength band. Wavelength division multiplexing (WDM) light that includes a plurality of wavelength groups, for example, M groups, is transmitted from a predetermined node to other nodes (n: constant between each node). There is known an optical network in which transmission is possible in parallel via optical input fibers and optical output fibers. In such an optical network, a node that performs path switching in units of wavelength groups or performs path switching in units of wavelengths (routing) is electrically connected to a signal for which the node is a destination by using a router or the like. For the electrical layer EL that performs signal conversion between the signal and the optical signal in units of wavelengths, from the m wavelength channels respectively included in the wavelength groups transmitted through the n optical input path fibers. The optical signal of a predetermined wavelength is extracted and dropped, or an optical signal converted from an electrical signal by a predetermined router is added (added) to wavelength division multiplexed light in a fiber in a predetermined optical path. An optical matrix switch device which is a large-scale multi-input multi-output optical switch device is used. Patent Document 1 describes an example thereof.

  By the way, as the node, for example, optical path cross-connect devices shown in FIGS. 8 and 9 have been proposed. The optical path cross-connect device of FIG. 8 is configured in a wavelength selective switch-based one-layer cross-connect configuration, provided for each of the K optical input fibers Fi1 to FiK, and from these optical input fibers Fi1 to FiK. K 1 × K wavelength selective switches WSS for selecting a wavelength from a wavelength constituting the wavelength division multiplexed light to an arbitrary optical output fiber among a plurality of (for example, K) optical output fibers Fo1 to FoK, and a plurality Provided for each of the K (K) optical output fibers Fo1 to FoK, and combines the wavelengths respectively output from the K 1 × K wavelength selective switches WSS, and among the K optical output fibers Fo1 to FoK, And K K × 1 optical combiners WBC that output to a desired optical output fiber whose wavelength is directed. In the optical path cross-connect device shown in FIG. 8, the K × 1 optical combiner WBC is configured in the same manner as the 1 × K wavelength group selection switch WSS and is used in the reverse direction. Has a symmetrical structure that can provide the same function. Further, the optical path cross-connect device shown in FIG. 9 is different from the optical path cross-connect device shown in FIG. 8 in that the K × 1 optical combiner WBC is configured by an optical coupler. It is configured. The optical path cross-connect device shown in FIG. 9 has an asymmetric structure, and the K × 1 optical combiner WBC is composed of an optical coupler, but has a characteristic that the loss of the optical combiner WBC is large. In the optical path cross-connect device shown in FIGS. 8 and 9, a desired optical output fiber to which an add signal transmitted from a router of the electrical layer EL at a predetermined wavelength is directed among K output fibers Fo1 to FoK. An add 1 × K wavelength selective switch WSS for adding to the wavelength division multiplexed light is provided. Further, a drop K × 1 optical combiner WBC for dropping a drop signal of a predetermined wavelength included in the wavelength division multiplexed light from the optical input fibers Fi1 to FiK to a desired router of the electrical layer EL is provided.

  In the optical path cross-connect device shown in FIGS. 8 and 9, the wavelength selective switch used in the apparatus is composed of K 1 × K wavelength selective switches WSS, and the number K of optical fibers is 100. Then, 100 1 × 100 wavelength selective switches are required. However, at present, the wavelength selective switch is configured by a wavelength selective switch configured by the three-dimensional MEMS optical switch shown in FIG. 10 or provided for each of the K optical input fibers shown in FIG. K demultiplexers each demultiplexing the wavelength division multiplexed light input for each wavelength, and K × m (m is a fiber) that performs path switching for each wavelength demultiplexed by the K demultiplexers. 1 × K optical switches) and the output wavelengths from these 1 × K optical switches are combined and output to each of K optical output fibers K × m K × It consists of one multiplexer. For this reason, if the K 1 × K wavelength selective switches are configured with a wavelength selective switch including, for example, a three-dimensional MEMS optical switch including mechanical elements as shown in FIG. In addition to the output fiber, in addition to the spectroscopic grating and the condensing lens, a micromirror having a wavelength of m per optical input fiber and an actuator for driving the same are required. There is also a problem that it is extremely expensive. Further, as shown in FIG. 11, K × m (where m is the number of wavelengths per fiber) 1 × K optical switches that perform path switching for each wavelength demultiplexed by K demultiplexers, and 1 of them. When it is composed of K K × 1 multiplexers that receive output wavelengths from × K optical switches, it can be integrated on a single substrate using planar optical waveguide (PLC) technology. However, since the 1 × K × m optical switch is composed of a large number of optical elements, there is a problem that the loss of light is large, and this is also difficult to put into practical use.

JP 2008-252664 A

  In contrast, an optical path cross-connect device having a two-layer cross-connect switch configuration of the wavelength group selection switch and the wavelength selection switch shown in FIGS. 12 and 13 can be considered. The optical path cross-connect device in FIG. 13 is configured in the same manner as the optical path cross-connect device in FIG. 12 except that the input / output is inverted and the names are different. Description is omitted. The optical path cross-connect device of FIG. 12 includes a wavelength group cross-connect unit BXC that performs path switching in units of wavelength groups and a wavelength cross-connect unit WXC that performs path switching in units of wavelengths mainly for recombination of wavelength groups. It is configured in two stages. The wavelength group cross-connect unit BXC selects K wavelength group selection switches WBSS1 for selecting the same path among the wavelengths included in the wavelength division multiplexed light respectively input from the K optical input fibers Fi1 to FiK. ~ WBSSK and wavelength groups output from these wavelength group selective switches WBSS1 ~ WBBSSK are combined and output to K optical output fibers Fo1 ~ Fok respectively, for example, combiners PCB1 ~ PCBk composed of optical couplers, and wavelengths The wavelength groups including the optical signals selected by the wavelength group selection switches WBSS1 to WBSK to combine the optical signals in the group in units of wavelengths or to drop the optical signals are combined to the wavelength cross-connect unit WXC. The output confluencers PCD1 to PCDK are provided. The wavelength cross-connect unit WXC is a wavelength selective switch that selects, for each route, an optical signal for switching the route or for dropping from the wavelength group output from the confluencers PCD1 to PCDK. Lights that combine the path switching wavelengths selected by the WSS1 to WSSk and the wavelength selective switches WSS1 to WSSk for each path and output to the optical output fibers Fo1 to FoK via the add optical couplers PCA1 to PCAK, respectively. Couplers PCW1 to PCWK, optical couplers PCd1 to PCdzyk that combine the optical signals of the drop wavelengths selected by the wavelength selective switches WSS1 to WSSk and output the signals for each of the array waveguide diffraction gratings AWGd1 to AWGdzyk to be dropped, and electricity Wavelength for each path from a plurality of wavelengths output from the arrayed waveguide gratings AWGa1 to AWGazyk that receives the optical signal from the layer EL Selected and a wavelength selective switch WSSa1~WSSazyk to be output to the photocoupler PCW1～PCWK. In FIG. 12, y is an add / drop rate from the wavelength group cross-connect unit BXC to the wavelength cross-connect unit WXC, and z is an add / drop rate from the wavelength cross-connect unit WXC to the electrical layer EL.

  The optical path cross-connect device shown in FIGS. 12 and 13 has an advantage that the cross-connect in the wavelength unit separated from the wavelength group unit is performed with respect to the optical path cross-connect device shown in FIGS. However, there is a problem that an additional wavelength cross-connect unit WXC for switching between wavelength groups in units of wavelengths is required.

The present invention has been made in the background of the above circumstances, and an object of the present invention is to provide a low-cost wavelength group optical path cross-connect device with a simple configuration that does not require the wavelength cross-connect unit WXC. There is.

In order to achieve the above object, the gist of the present invention is as follows: (a) a wavelength-division multiplexed light from a plurality of optical input fibers intervening as a node in an optical network according to a wavelength group composed of a plurality of wavelengths; A wavelength group optical path cross-connect device for routing to a plurality of optical output fibers, wherein (b) each wavelength division multiplexed light from the plurality of optical input fibers is terminated at the node for each of the plurality of optical input fibers. A drop wavelength demultiplexer for separating an optical signal to be transmitted; and (c) an optical signal other than the optical signal terminating at the node among the wavelength division multiplexed lights, according to a wavelength group, the plurality of optical output fibers. (D) a wavelength group optical combiner that combines each optical output fiber among the wavelength groups selected by the wavelength group selective switch, and (e) The optical signal generated by the node, the optical signal of the plurality of optical output fiber and add-merging unit for combining the optical output fiber directed, characterized in that it contains.

According to the wavelength group optical path cross-connect device of the present invention configured as described above, the path switching in units of wavelength groups is performed by the wavelength group selective switch and the wavelength group optical combiner, and the wavelength demultiplexing for dropping is performed. Since the drop signal is separated from the wavelength group by the unit, and the add signal is joined to the wavelength group by the add merging unit, the wavelength selective switch and the wavelength cross-connect unit WXC including the same are not required. An inexpensive wavelength group optical path cross-connect device can be obtained with a simple configuration.

  Here, it is preferable that the drop wavelength demultiplexing unit is provided in each of the plurality of optical input fibers and separates a plurality of 1 × wavelengths for separating a drop wavelength from wavelength division multiplexed light transmitted through the optical input fiber. A two-wavelength selective switch, and an arrayed waveguide diffraction grating for inputting a drop wavelength separated by each of the plurality of 1 × 2 wavelength selective switches to a predetermined optical receiver among the plurality of optical receivers in the electrical layer; Is included. Regarding the drop of the optical signal at the node, there is an advantage that the wavelength selective switch becomes as small as possible.

  Preferably, the drop wavelength demultiplexing unit is provided in each of the plurality of optical input fibers and separates a plurality of 1 × 2 wavelengths for separating a drop wavelength from wavelength division multiplexed light transmitted through the optical input fibers. Array waveguide diffraction for inputting drop wavelengths respectively separated by an optical coupler (optical branching element) and the plurality of 1 × 2 optical couplers to a predetermined optical receiver among the plurality of optical receivers in the electrical layer. Including a lattice. In this way, there is an advantage that the optical signal can be dropped economically at the node.

  Preferably, the add merging unit includes an arrayed waveguide diffraction grating that multiplexes optical signals having an add wavelength output from a predetermined optical transmitter among the plurality of optical transmitters in the electrical layer. A plurality of 2 × 1 wavelength selective switches that are provided in the plurality of optical output fibers, respectively, and add optical signals of the add wavelength from the arrayed waveguide diffraction grating to the wavelength division multiplexed light transmitted through the optical output fibers. Are included. In this way, there is an advantage that the wavelength selective switch becomes as small as possible with respect to the addition of the optical signal at the node.

  Preferably, the add merging unit includes an arrayed waveguide diffraction grating that multiplexes optical signals having an add wavelength output from a predetermined optical transmitter among the plurality of optical transmitters in the electrical layer. A plurality of 2 × 1 optical couplers that are provided in each of the plurality of optical output fibers and that combine the wavelength division multiplexed light transmitted through the optical output fibers with the optical signal having the add wavelength from the arrayed waveguide grating. Is included. In this way, there is an advantage that the optical signal can be added economically in the node.

  Preferably, the wavelength division multiplexed light is composed of wavelength channels of continuous wavelengths having sequentially different wavelengths. In this way, since a wavelength channel of continuous wavelengths is used, there is an advantage that the design is easy.

  Preferably, the wavelength division multiplexed light includes wavelength channels having discontinuous wavelengths. In this way, there is an advantage that the degree of freedom of design is increased.

  Preferably, the wavelength division multiplexed light includes wavelength channels having different bit trades of signals. In this way, the versatility of the optical path cross-connect device is enhanced.

  Preferably, the wavelength division multiplexed light includes wavelength channels having wavelengths having different wavelength intervals. In this way, the versatility of the optical path cross-connect device is enhanced.

  Preferably, the wavelength group optical combiner and the add confluence unit are composed of wavelength selective switches used in opposite directions. In this way, the number of types of elements constituting the optical path cross-connect device is reduced, manufacturing becomes easy, and there is an advantage that the optical path cross-connect device can be integrated on a common substrate by using the planar optical waveguide technology to be monolithic.

  Preferably, the optical input fiber of the optical path cross-connect device is used as an optical output fiber, the optical output fiber of the optical path cross-connect device is used as an optical input fiber, and functions as an optical path cross-connect device in the reverse direction. It is something to be made. This increases the degree of freedom in node design.

  Preferably, the optical path cross-connect device uses a planar optical waveguide circuit (PLC) technology, the drop wavelength demultiplexer, the wavelength group selection switch, the wavelength group optical combiner, the add combiner, All or part of the add wavelength demultiplexer is formed and integrated on a common substrate to form a monolithic structure. In this way, the optical path cross-connect device is not only reduced in size, but also the productivity is improved and the cost is further reduced.

It is a conceptual diagram for demonstrating the optical network containing the optical path cross-connect apparatus of one Example of this invention. It is a figure explaining the function of the optical path cross-connect apparatus which comprises a node in the optical network of FIG. It is a figure explaining the case where it is the wavelength division multiplexing light transmitted in the optical network of FIG. 1, and is comprised from a continuous arrangement type wavelength group. It is a figure explaining the case where it is the wavelength division multiplexing light transmitted in the optical network of FIG. 1, and is comprised from a discontinuous arrangement type wavelength group. It is the schematic explaining the principal part structure of the optical path cross-connect apparatus of FIG. 1 and FIG. It is a figure explaining the structure of the wavelength group selection switch used for the optical path cross-connect apparatus of FIG. It is a figure explaining the function of cyclic AWG contained in the wavelength group selection switch of FIG. It is the schematic explaining the structure of the conventional optical path cross-connect apparatus which has a 1 step | paragraph type | formula wavelength selective switch. It is the schematic explaining the structure of the other conventional optical path cross-connect apparatus which has a 1 step | paragraph type | formula wavelength selective switch. It is a figure explaining the example of the wavelength selective switch with which the wavelength selective switch of the optical path cross-connect apparatus of FIG. 8 or FIG. 9 was comprised by the three-dimensional MEMS optical switch. FIG. 10 is a diagram for explaining an example in which the wavelength selection switch of the optical path cross-connect device of FIG. 8 or FIG. 9 is configured from a demultiplexer, an optical switch, and a multiplexer that can be integrated. It is the schematic explaining the structural example of the two-layer type optical path cross-connect apparatus of a wavelength group selection switch and a wavelength selection switch. It is the schematic explaining the other structural example of the two-layer type | formula optical path cross-connect apparatus of a wavelength group selection switch and a wavelength selection switch.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 illustrates a part of an optical network NW including a plurality of nodes # 0 to #D and an optical fiber F connecting them. D is a positive integer indicating the number of nodes excluding node # 0. FIG. 2 shows input / output of a wavelength group optical path cross-connect device (hereinafter simply referred to as an optical path cross-connect device) OXC constituting the node # 0. As shown in FIG. 2, a total of K optical input fibers Fi1 to Fik from each node # 1 to #D are connected to the optical path cross-connect device OXC, and a total K to each node # 1 to #D is connected. The optical output fibers Fo1 to FoK are connected. Assuming that the optical input fibers and optical output fibers connected to adjacent nodes are constant, for example, n bundles, K is represented by n × D.

  In the present embodiment, L waves are obtained by combining optical signals of a plurality of m wavelengths corresponding respectively to a plurality of wavelength channels (wave channels or light paths) divided every 100 GHz of a predetermined communication wavelength band. 1 wavelength group WB is configured, and M (M sets) wavelength groups WB are combined to form one wavelength division multiplexed (WDM) light, and the wavelength division multiplexed light Are transmitted for each optical fiber. That is, WB11 to WB1M, WB21 to WB2M,... WBK1 to WBKM are input in parallel through the input side optical fibers Fi1, Fi2,..., FiK, respectively, and routed new wavelength groups WB11 to WB1M, WB21 to WB2M,... WBK1 to WBKM are output in parallel via the output side optical fibers Fo1, Fo2,. The m, M, and K are integers, and are set to, for example, m = 4 to 8, M = 8 to 10, K = 10 to 12, and the like. The number of wavelengths m for each optical fiber is represented by L × M.

  Here, for example, the wavelengths of the wavelength channels included in the wavelength group WB11 are λ111 to λ11L, the wavelengths of the wavelength channels included in the wavelength group WB12 are λ121 to λ12m, and the wavelengths of the wavelength channels included in the wavelength group WB1M are λ1M1 to λ1Mm The wavelengths of the wavelength channels included in the group WBKM are λKM1 to λKMm, and these wavelengths, for example, λ121 to λ121L may be successively increased with respect to each other or may be dispersive. Good.

  3 and 4 show configuration examples of the wavelength λ constituting each wavelength group. FIG. 3 shows an example of a continuously arranged wavelength group. A plurality of wavelength groups sequentially selected so as to form one group for every 16 consecutive wavelengths selected from continuous wavelengths are set. ing. FIG. 4 shows an example of a dispersion-arranged wavelength group. A wavelength group is configured by setting one wavelength group from wavelengths that are dispersively selected from a set of eight consecutive wavelengths. . One group is configured such that the wavelengths are constituted by wavelengths that discontinuously differ within the wavelength group and between the wavelength groups.

  3 and 4, the wavelength channels constituting the wavelength division multiplexed optical signal may be optical signals having the same bit rate, or part or all of the optical signals may be different from each other. May be. Also, as shown in FIG. 4, the wavelength channels do not necessarily have to be equally spaced, and some or all of the wavelength channels may be wavelength channels that are not evenly spaced.

  As shown in FIG. 5, the optical path cross-connect device OXC includes a predetermined wavelength group or wavelength included in the wavelength division multiplexed light respectively input through the K input-side optical fibers Fi1, Fi2,. Are extracted and incorporated into other desired wavelength division multiplexed light and transmitted through a desired optical output fiber among the K optical output fibers Fo1, Fo2,... FoK. The optical path cross-connect device OXC is provided for each of the K input side optical fibers Fi1, Fi2,... FiK, and the wavelengths transmitted for each of the input side optical fibers Fi1, Fi2,. The K 1 × 2 wavelength selective switches WSSd1 to WSSdK that respectively select optical signals of the drop wavelength from the division multiplexed light and the drop wavelength optical signals selected by the 1 × 2 wavelength selective switches WSSd1 to WSSdK according to the wavelength One of K drop arrayed waveguide diffraction gratings AWGd1 to AWGdK to be inputted to a predetermined optical receiver PD among a plurality of routers (optical receivers) in the electric layer EL and one of these 1 × 2 wavelength selective switches WSS Are provided corresponding to each of K 1 × K wavelength group selection switches WBSS1 to WBSK and K output-side optical fibers Fo1, Fo2,. The wavelength groups output from the 1 × K wavelength group selection switch WBSS toward the desired optical output fiber are combined and output to the K output side optical fibers Fo1, Fo2,. An optical signal of an add wavelength output from a predetermined optical transmitter PI among a plurality of routers (optical transmitters) in the electrical layer EL and the K × 1 wavelength group multiplexers WBC1 to WBCK on the output side K add array waveguide diffraction gratings AWGa1 to AWGaK and K pieces of K × 1 wavelength group combined to be output to be combined with a predetermined optical output fiber among optical fibers Fo1, Fo2,. Are provided between the optical units WBC1 to WBCK and the K output side optical fibers Fo1, Fo2,... FoK, and add wavelength light to the wavelength division multiplexed light output from the K number of K × 1 combiners WBC. K 2 × 1 wavelength selective switches WSS for combining signals a1 to WSSaK.

  In the present embodiment, the K 1 × 2 wavelength selective switches WSSd1 to WSSdK and the K drop arrayed waveguide diffraction gratings AWGd1 to AWGdK are supplied from a plurality of optical input fibers Fi1, Fi2,. It functions as a drop wavelength demultiplexer that separates an optical signal having a drop wavelength that terminates at node # 0 from each wavelength division multiplexed light for each of the plurality of optical input fibers. Further, K array waveguide diffraction gratings AWGa1 to AWGaK and K number of 2 × 1 wavelength selective switches WSSa1 to WSSaK convert optical signals of the add wavelength generated at node # 0 into a plurality of optical output fibers. It functions as a merging adder for merging into the optical output fiber to which the optical signal is directed among Fo1, Fo2,... FoK.

  The 1 × 2 wavelength selective switch WSS is configured by, for example, a wavelength selective switch configured by a three-dimensional MEMS optical switch illustrated in FIG. 10 or a planar wavelength selective switch illustrated in FIG. The wavelength selective switch configured by the three-dimensional MEMS optical switch shown in FIG. 10 is described using one optical input fiber Fi and two optical output fibers Fo1 to Fo2. This three-dimensional MEMS optical switch has a number m of wavelengths in the wavelength division multiplexed light transmitted in one optical fiber in addition to the spectroscopic grating G and the condenser lens L (shown as four in FIG. 10). ) And an actuator (not shown) for driving the same, and the wavelength input from the optical input fiber Fi is dispersed in the wavelength unit by the spectral grating G and then condensed on the micromirror MM by the condenser lens L. Then, the reflected light from the micromirror MM is driven so as to enter the desired output fibers Fo1 to Fo2, so that an optical signal having a desired drop wavelength is selected from the wavelength division multiplexed light and two optical output fibers are selected. A wavelength selective switch function for outputting from any one of Fo1 to Fo2 is obtained.

  The planar wavelength selective switch shown in FIG. 11 is configured by integrating a waveguide and an element on a common semiconductor or a substrate such as quartz by a planar optical waveguide circuit (PLC) technique. This planar wavelength selective switch is provided, for example, for each of K optical input fibers Fi1, Fi2,..., FiK, and separates (divides) K wavelength-division multiplexed lights that are respectively input for each wavelength. 1 × m (where m is the number of wavelengths per fiber) demultiplexer WS and K 1 × m demultiplexers WS are used to perform path switching for each wavelength demultiplexed by K × m 1 × K Each of the optical switches PSW and the output wavelengths from the 1 × K optical switch PSW is received and combined, and output to any one of K optical output fibers Fo1, Fo2,... FoK. It is composed of an m × 1 multiplexer WC. When this planar selection switch is adopted as the 1 × K wavelength selection switch WSS in FIG. 5, the optical path cross-connect device OXC in FIG. 5 is partially or entirely integrated on a common semiconductor substrate. .

  In FIG. 11, instead of the 1 × m (m is the number of wavelengths per fiber) wavelength demultiplexer, the 1 × M (M is the number of wavelengths per wavelength group) wavelength group demultiplexer shown in FIG. By using an M × 1 wavelength group multiplexer using 1 × M (M is the number of wavelengths per wavelength group) shown in FIG. 7 in the reverse direction instead of the wave WC, 1 × K planar wavelength group selection A switch can be configured.

  The 1 × K wavelength group selection switches WBSS1 to WBSK in FIG. 5 are shown in FIG. 6 when K = 5. In FIG. 6, the 1 × n wavelength group selection switch WBSS includes a first circular array waveguide diffraction grating AWG1, five 1 × 5 optical switches PSW, and five 5 × 1 second circular array waveguides. It comprises a diffraction grating AWG2. The above-mentioned first orbiting array waveguide diffraction grating AWG1 and second orbiting array waveguide diffraction grating AWG2 have a circular characteristic for output by matching the product of the number of output ports and the wavelength interval to FSR (Free Spectral Range). It is constituted by a circular array waveguide diffraction grating AWG provided with. The first circular array waveguide diffraction grating AWG1 demultiplexes the input wavelength division multiplexed light into five wavelength groups as shown in FIG. FIG. 7 shows an example where 40 wavelength groups of λ1 to λ40 output five wavelength groups WB1 to WB5. The 1 × 5 optical switch PSW can be formed of a known optical switch. For example, an MZI switch using a Mach-Zehnder-interferometer is convenient for adopting an optical integrated circuit using a PLC. The 5 × 1 second orbiting array waveguide diffraction grating AWG2 is composed of the orbiting array waveguide diffraction grating AWG. However, by using it in the opposite direction, the wavelength group is multiplexed and the path is switched. It functions as a wavelength group multiplexer that outputs toward the previous optical output fiber.

  Returning to FIG. 5, the K K × 1 wavelength group multiplexers WBC1 to WBCK are predetermined ones of the plurality of optical output fibers Fo1, Fo2,... FoK from the 1 × K wavelength group selection switches WBSS1 to WBSK. The wavelength groups output toward the optical output fiber are merged and output toward the predetermined optical output fiber. The K × 1 wavelength group multiplexers WBC1 to WBCK can be configured by optical couplers, but have the same configuration as the 1 × K wavelength group selection switches WBSS1 to WBSK of this embodiment and are used in the reverse direction. Consists of.

  The optical signal of the add wavelength generated at the node # 0 sent by the K array waveguide diffraction gratings AWGa1 to AWGaK is sent to a plurality of optical output fibers by the K 2 × 1 wavelength selective switches WSSa1 to WSSaK. Of Fo1, Fo2,..., FoK, the optical signal is directed to the optical output fiber. Each of the add array waveguide diffraction gratings AWGa1 to AWGaK and the 2 × 1 wavelength selective switches WSSa1 to WSSaK can also be configured by an optical coupler.

  That is, in the optical path cross-connect device OXC of this embodiment, the wavelength division multiplexed light respectively input through the K input side optical fibers Fi1, Fi2,... FiK is 1 × K wavelength group selective switch WBSS1. Route switching is performed in units of group wavelengths by WBSK and K × 1 wavelength group multiplexers WBC1 to WBCK. Further, in the optical path cross-connect device OXC of this embodiment, a predetermined (arbitrary) drop wavelength is selected from the wavelength division multiplexed light respectively input through the K input-side optical fibers Fi1, Fi2,. A predetermined (arbitrary) reception among a plurality of receivers (routers) PD in the electrical layer EL for performing signal conversion between an electrical signal and an optical signal in wavelength unit provided with a router or the like A drop function to the transmitter, and an optical signal that is added (added) from a predetermined (arbitrary) transmitter among a plurality of transmitters (routers) PI in the electrical layer EL, that is, an added wavelength is a predetermined wavelength division multiplexed light. And an add function for transmitting from any one of the optical output fibers Fo1, Fo2,... FoK through which the signal is added and the predetermined wavelength division multiplexed optical signal is transmitted. Note that the optical network NW is designed so that wavelengths are not overlapped with each other in order to avoid wavelength collision. The transmitter PI searches for a free wavelength and outputs an optical signal of that wavelength.

  Here, the K × 1 wavelength group multiplexers WBC1 to WBCK are configured in the same manner as the reverse K × 1 wavelength group selection switches WBSS1 to WBSK, and the 2 × 1 wavelength selection switches WSSa1 to WSSaK are 1 × in the reverse direction. When configured in the same way as the two-wavelength selective switches WSSd1 to WSSdK, the optical path cross-connect device OXC has the advantage that the input and output are in the reverse direction, and the add and drop are used in reverse.

  As described above, according to the optical path cross-connect device OXC of this embodiment, the wavelength division multiplexed light respectively input through the K input-side optical fibers Fi1, Fi2,. The path switching is performed on a wavelength group basis by the wavelength group selection switches WBSS1 to WBSK and the K × 1 wavelength group multiplexers WBC1 to WBCK. Further, K 1 × 2 wavelength selective switches WSSd1 to WSSdK and K drop arrayed waveguide diffraction gratings AWGd1 to AWGdK are wavelength division multiplexed from a plurality of optical input fibers Fi1, Fi2,. Functions as a drop wavelength demultiplexing unit or a drop wavelength demultiplexer for separating a drop wavelength optical signal terminated at node # 0 from the light for each of the plurality of optical input fibers, and an array of K add The waveguide diffraction gratings AWGa1 to AWGaK and the K 2 × 1 wavelength selective switches WSSa1 to WSSaK convert the optical signal of the add wavelength generated at the node # 0 into a plurality of optical output fibers Fo1, Fo2,. Of these, it functions as an add wavelength combiner or add adder that joins the optical output fiber to which the optical signal is directed. Therefore, an inexpensive optical path cross-connect device can be obtained with a simple configuration that does not require the wavelength selective switch or the wavelength cross-connect unit WXC including the wavelength selective switch.

  Further, according to the optical path cross-connect device OXC of the present embodiment, drop wavelength demultiplexers are respectively provided in the plurality of optical input fibers and transmitted by the optical input fibers Fi1, Fi2,. The K 1 × 2 wavelength selective switches WSSd1 to WSSdK for separating the drop wavelength from the wavelength division multiplexed light and the drop wavelengths respectively separated by the plurality of 1 × 2 wavelength selective switches are used as a plurality of light of the electric layer EL. This includes K drop arrayed-waveguide diffraction gratings AWGd1 to AWGdK that are input to a predetermined optical receiver PD among the receivers. Regarding the drop of the optical signal at the node, there is an advantage that the wavelength selective switch becomes as small as possible. Further, there is an advantage that an optical configuration can be economically configured with respect to the drop of the optical signal at the node by using K 1 × 2 optical couplers instead of K 1 × 2 wavelength selective switches WSSd1 to WSSdK.

  Further, according to the optical path cross-connect device OXC of the present embodiment, the add combiner receives the optical signal of the add wavelength output from the predetermined optical transmitter PI among the plurality of optical transmitters of the electrical layer EL. The wavelength-division multiplexed light transmitted to each of the K add array waveguide diffraction gratings AWGa1 to AWGaK and the K optical output fibers Fo1, Fo2,. It includes K 2 × 1 wavelength selective switches WSSa1 to WSSaK that join optical signals with add wavelengths from the arrayed waveguide diffraction grating. In this way, there is an advantage that the wavelength selective switch becomes as small as possible with respect to the addition of the optical signal at the node. In addition, there is an advantage that an optical signal can be added economically at the node by using K 2 × 1 optical couplers instead of K 2 × 1 wavelength selective switches WSSa1 to WSSaK.

  Further, according to the optical path cross-connect device OXC of the present embodiment, the wavelength division multiplexed light is composed of continuous wavelength channels having sequentially different wavelengths. In this way, since a wavelength channel of continuous wavelengths is used, there is an advantage that the design is easy.

  Further, according to the optical path cross-connect device OXC of the present embodiment, the wavelength division multiplexed light is configured to include wavelength channels having discontinuous wavelengths, so that there is an advantage that the degree of freedom in design is increased.

  Further, according to the optical path cross-connect device OXC of this embodiment, the wavelength division multiplexed light is configured to include wavelength channels having different signal bit trades. Is increased.

  Further, according to the optical path cross-connect device OXC of the present embodiment, the wavelength division multiplexed light is composed of wavelength channels with wavelengths having different wavelength intervals, so that the versatility of the optical path cross-connect device OXC is enhanced. .

  Further, according to the optical path cross-connect device OXC of the present embodiment, the K × 1 wavelength group combiners WBC1 to WBCK are composed of 1 × K wavelength selective switches WBSS1 to WBSK used in the reverse direction. For this reason, there are advantages that the number of types of elements constituting the optical path cross-connect device OXC is reduced, the manufacturing becomes easy, and the optical path cross-connect device OXC can be monolithically integrated on a common substrate using the planar optical waveguide technology.

  Further, according to the optical path cross-connect device OXC of this embodiment, the optical input fibers Fi1, Fi2,... FiK are used as optical output fibers, and the optical output fibers Fo1, Fo2,. -Since FoK can be used as an optical input fiber and can function as an optical path cross-connect device in the reverse direction, the degree of freedom in node design is increased.

  Further, according to the optical path cross-connect device OXC of the present embodiment, using the planar optical waveguide circuit (PLC) technology, 1 × 2 wavelength selective switches WSSd1 to WSSdK, drop array waveguide diffraction gratings AWGd1 to AWGdK, 1 × K wavelength group selection switches WBSS1 to WBSK, K × 1 wavelength group combiners WBC1 to WBCK, add array waveguide diffraction gratings AWGa1 to AWGaK, 2 × 1 wavelength selection switches WSSa1 to WSSaK, all or part of them in common A monolithic structure is formed by integrating on a substrate. In this way, the optical path cross-connect device OXC is not only reduced in size, but also the productivity is improved and the cost is further reduced.

   In addition, although not illustrated one by one, the present invention can be variously modified without departing from the spirit of the present invention.

OXC: Optical path cross-connect device WSSd1 to WSSdK: 1 × 2 wavelength selective switch AWGd1 to AWGdK: Drop array waveguide diffraction grating (drop wavelength demultiplexing unit)
WBSS1 to WBBSK: 1 × K wavelength group selection switch WBC1 to WBCK: K × 1 wavelength group combiner AWGa1 to AWGaK: array waveguide diffraction grating for add (add wavelength merge portion)
WSSa1 to WSSaK: 2 × 1 wavelength selective switches Fo1, Fo2,... FoK: optical output fibers Fi1, Fi2,... FiK: optical input fibers

Claims (9)

A wavelength group optical path cross-connect device that intervenes as a node in an optical network and routes wavelength division multiplexed light from a plurality of optical input fibers to a plurality of optical output fibers according to a wavelength group consisting of a plurality of wavelengths ,
A drop wavelength demultiplexing unit that separates an optical signal terminated at the node for each of the plurality of optical input fibers from each of the wavelength division multiplexed light from the plurality of optical input fibers;
A wavelength group selection switch that can select any one of the plurality of optical output fibers according to the wavelength group, an optical signal other than an optical signal that terminates at the node among the wavelength division multiplexed lights, and
A wavelength group optical combiner that combines each optical output fiber among the wavelength groups selected by the wavelength group selection switch;
A wavelength group optical path cross-connect device , comprising: an add merging unit that joins an optical signal generated at the node to an optical output fiber to which the optical signal is directed among the plurality of optical output fibers . The drop wavelength demultiplexing unit is provided in each of the plurality of optical input fibers, and a plurality of 1 × 2 wavelength selective switches or 1 for separating a drop wavelength from wavelength division multiplexed light transmitted through the optical input fiber A × 2 optical coupler, and an arrayed waveguide diffraction grating for inputting the drop wavelength separated by the plurality of 1 × 2 wavelength selective switches to a predetermined optical receiver among the plurality of optical receivers in the electrical layer. The wavelength group optical path cross-connect device according to claim 1, comprising: The add merging unit includes an arrayed waveguide diffraction grating that multiplexes an optical signal having an add wavelength output from a predetermined light transmitter among the plurality of light transmitters in the electrical layer, and the plurality of light beams. A plurality of 2 × 1 wavelength selective switches or 2 × 1 light, each of which is provided in the output fiber and joins the optical signal of the add wavelength from the arrayed waveguide diffraction grating to the wavelength division multiplexed light transmitted through the optical output fiber. The wavelength group optical path cross-connect device according to claim 1, further comprising a coupler. The wavelength group optical path cross-connect device according to any one of claims 1 to 3, wherein the wavelength division multiplexed light is composed of wavelength channels having continuous wavelengths that are sequentially different in wavelength. 4. The wavelength group optical path cross-connect device according to claim 1, wherein the wavelength division multiplexed light is constituted by wavelength channels having discontinuous wavelengths. 6. The wavelength group optical path cross-connect device according to claim 1, wherein the wavelength division multiplexed light includes wavelength channels having different signal bit rates. 7. The wavelength group optical path cross-connect device according to claim 1, wherein the wavelength division multiplexed light includes wavelength channels having wavelengths having different wavelength intervals. The wavelength group optical path cross-connect device according to any one of claims 1 to 7, wherein the wavelength group optical combiner and the add combining unit are configured by wavelength selective switches used in opposite directions. The optical input fiber of the optical path cross-connect device is used as an optical output fiber, the optical output fiber of the optical path cross-connect device is used as an optical input fiber, and functions as an optical path cross-connect device in the reverse direction. The wavelength group optical path cross-connect device according to any one of claims 1 to 8.

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