Optical wavelength conversion cross-connect device and optical network system

Abstract

Provided is an optical wavelength conversion cross-connect device (100, 100A) in which an input path and an output path are connected, the optical wavelength conversion cross-connect device (100, 100A) including: an optical cross-connect device (OXC) (10) that switches wavelength-multiplexed signal light, obtained by multiplexing each optical signal of a plurality of wavelength bands input from the input path, for each path by using a WSS, and outputs the wavelength-multiplexed signal light to the output path; and a wavelength conversion function unit (110) that converts the wavelength of the wavelength-multiplexed signal light of which the path is switched by the optical cross-connect device (OXC) (10). An optical network system (1000) includes an optical wavelength conversion cross-connect device (100, 100A) that is connected as a relay node of an optical signal to an optical fiber of a path combining a plurality of optical fibers into a single path.

Description

Optical wavelength conversion cross-connect device and optical network system

[0001] The present invention relates to an optical wavelength conversion cross-connect device and an optical network system used for multiband transmission in which wavelength-multiplexed signal light, in which optical signals in a plurality of different wavelength bands are multiplexed, is transmitted over an optical fiber.

[0002] Conventionally, wavelength cross-connect devices are connected as relay nodes for optical signals to optical fibers of a path (optical transmission path) that bundles together multiple optical fibers in an optical network. Wavelength cross-connect devices are used, for example, in reconfigurable optical add / drop multiplexers (ROADMs) that act as path switches for optical signals transmitted using various modulation methods such as wavelength division multiplexing in optical networks. In this wavelength cross-connect device, wavelength-multiplexed signal light transmitted from an input path is output to an output path via multiple wavelength selective switches (WSSs).

[0003] A WSS is an optical switch that not only has the wavelength multiplexing / demultiplexing function of connecting input WDM (Wavelength Division Multiplexing) signals to different output ports for each wavelength, but also has the ability to change the combination of wavelength and output port.By using a WSS, on-site work is not required when changing the transmitting and receiving wavelengths, and path changes can be made quickly by remote operation.

[0004] A wavelength cross-connect device enables the switching of optical signal paths in a wavelength multiplexing transmission system. Generally, a wavelength cross-connect device is capable of switching any optical path (see Non-Patent Document 1).

[0005] Fig. 14 is a diagram showing the configuration of a wavelength multiplexing transmission system including the wavelength cross-connect device described in Non-Patent Document 1. The wavelength multiplexing transmission system 1 shown in Fig. 14 is an optical transmission system based on Dense Wave-Division Multiplexing (DWDM), which multiplexes multiple wavelength signals onto a single optical fiber, and digital coherent technology. The wavelength multiplexing transmission system 1 includes an optical cross-connect (OXC) device 10 as an optical node, optical fibers 20a to 20c (maximum eight paths) (collectively referred to as optical fibers 20) as paths (optical transmission paths) connecting the OXCs 10 together, an optical amplifier / Raman amplifier 30 having an optical amplifier 30a that amplifies an optical signal using the optical fiber itself as an amplification medium, an OXC Network Operation System (NE-OpS) server 40 that controls the OXC 10 and the optical amplifier / Raman amplifier 30, and a monitoring and control terminal 50 that monitors the wavelength multiplexing transmission system 1 in cooperation with the OXC NE-OpS server 40. The OXC NE-OpS server 40 controls and operates the operation and maintenance of the OXC 10. The monitor control terminal 50 is configured by a computer (not shown).

[0006] The OXC 10 relays optical signals between OXCs, switches the optical signal routes, etc. The OXC 10 includes an optical cross-connect unit 11 that can set any optical path to be added, dropped, or passed through for up to eight transmission paths, an add / drop function unit (optical multiplexer / demultiplexer) 12 that is made up of a multiplexer / demultiplexer, and transponders (TRPDs) 13a to 13d (collectively referred to as transponders 13).

[0007] OXC 10A, to which clients such as communication terminals (not shown) are connected, connects client signals GbE / 10GbE / 100GbE / 400GbE to transponders 13a-13d in that order. Transponders 13a-13d relay client signals GbE / 10GbE / 100GbE / 400GbE transmitted and received between the clients via optical transmission paths such as optical fibers. Information about the client and the like is superimposed on the optical signals. Add / Drop function unit (optical multiplexing / demultiplexing unit) 12 multiplexes optical signals of different wavelengths and performs processing to demultiplex the multiplexed optical signals.

[0008] The add / drop function unit 12 of the OXC 10A is connected to the transponders 13a to 13d. The add / drop function unit 12 multiplexes or demultiplexes the optical signals received from the transponders 13a to 13d and outputs the multiplexed or demultiplexed signals to the optical cross-connect unit 11.

[0009] The optical cross-connect unit 11 of the OXC 10A transmits an optical signal of a specified wavelength to a specified route in response to instructions from the OXC NE-OpS server 40. The optical cross-connect unit 11 of the client OXC 10A performs switching between the client and one of eight routes (optical transmission paths). The optical cross-connect unit 11 can set any optical path to be added, dropped, or passed through for up to eight transmission paths.

[0010] By switching to DP-16QAM (Dual Polarization-16 Quadrature Amplitude Modulation), the wavelength division multiplexing transmission system 1 doubles the transmission speed per wavelength to 200 Gbit / s. By using two channels of 200 Gbit / s optical signals in 400 Gbit / s multi-channel optical transmission (see waveform diagram a in Figure 14), a data transmission speed of 400 Gbit / s is achieved.

[0011] The relay OXC 10B connects optical signals transmitted from the optical fibers 20a-20d to the optical cross-connect unit 11, which transmits optical signals of a predetermined wavelength to the add / drop functional unit 12 in response to instructions from the OXC NE-OpS server 40. The optical cross-connect unit 11 sets the add / drop functional unit 12 to add, drop, or pass optical paths. The add / drop functional unit 12 multiplexes optical signals of different wavelengths and demultiplexes the multiplexed optical signals. The transponders 13a-13d relay optical signals demultiplexed by wavelength from the add / drop functional unit 12. The transponders 13a-13d, for example, map the received 400 GbE signal from the OTUC4 frame, which is an OTN signal, into four OTUC frames of 100 Gbit / s each, using a framer and signal processing unit (not shown) within the transponder. 400 GbE data is transmitted by transferring two OTUC frames to each 200 Gbit / s optical signal. This allows the wavelength multiplexing transmission system 1 to accommodate 400 GbE client IFs.

[0012] The wavelength multiplexing optical transmission system 1 (FIG. 14) described above enables optical transmission and reception by multiplexing a plurality of optical wavelengths within one optical fiber.

[0013] 15 is a diagram showing a schematic configuration of an optical network system 2 using the technology of the wavelength division multiplexing optical transmission system 1 of FIG. 14. The same components as those in FIG. 14 are assigned the same reference numerals. The optical network system 2 shown in FIG. 15 includes an optical cross-connect device (OXC) 10. １１ ~10 ＮＭ The OXC10 serves as a node, and configures a ROADM system that enables optical signal addition and drop at each node. １１ , 10 Ｎ１ 15, the Add / Drop function unit 12 and the transponder 13 are connected to the OXC 10 via the optical cross-connect unit 11. １１ , 10 Ｎ１ , 10 ２Ｍ It is written outside.

[0014] The optical network system 2 includes: １１ ~10 ＮＭ By providing this, it is possible to switch any optical wavelength (optical path) to a different route, and to configure a mesh optical network. １１ and OXC10 ２１ 15. The optical signals of the optical wavelengths λ1 to λn shown by the symbol b in FIG. １１ , 10 Ｎ１ , 10 ２Ｍ By providing the add / drop function unit 12, it is possible to add and drop optical paths, and it is possible to add and drop any optical path.

[0015] "Practical Application of Beyond 100G Optical Cross-Connect (B100G-OXC) Systems," NTT Technical Journal, [online], [Retrieved December 4, 2023], Internet <URL: https: / / journal.ntt.co.jp / article / 14780> "Proposal of a Method for Obtaining Optical Signal Transmission Characteristics Using All-Optical Waveband Conversion Technology Adapted to All-Photonics Networks," IEICE PN Study Group, IEICE Technical Report PN2022-30, October 2022. "Characteristics of Wavelength Conversion Circuits Using Optical-Analog-Optical Methods B-12-18," IEICE General Conference, held online from March 15 to 18, 2022.

[0016] However, in the above-described optical network system 2, when switching an optical path to a different route in the optical cross connect (OXC 10 in FIG. 15), the signal wavelength of the optical path cannot be changed.

[0017] FIG. 16 is a diagram illustrating an optical path switching method in a conventional optical network system 2. Components identical to those in FIG. 15 are designated by the same reference numerals. In the optical cross-connect device (OXC) 10, when switching an optical path to a different path, the signal wavelength of the optical path cannot be changed. Therefore, as shown in FIG. 16, when connecting optical fibers with different characteristics (e.g., connecting single-mode fiber (SMF) to dispersion-shifted fiber (DSF)), the signal is first terminated at transponder (TRPD) 13a and then connected to transponder (TRPD) 13b, which generates a signal with an optical wavelength appropriate for the different fiber. This increases the network (NW) cost and power consumption in the connection between transponder 13a and transponder 13b, and also causes delays.

[0018] The present invention has been made in consideration of the above circumstances, and aims to provide an optical wavelength conversion cross-connect device and an optical network system that can reduce network costs and power consumption and suppress delays.

[0019] In order to solve the above-mentioned problems, an optical wavelength conversion cross-connect device is provided which connects an input route and an output route, and which is characterized by comprising: an optical cross-connect function unit which switches the wavelength-multiplexed signal light, which is multiplexed by each optical signal of a plurality of wavelength bands input from the input route, for each route using a WSS (Wavelength Selective Switch) and outputs it to the output route; and a wavelength conversion function unit which converts the wavelength of the wavelength-multiplexed signal light whose route is switched by the optical cross-connect function unit.

[0020] According to the present invention, it is possible to provide a wavelength cross-connect device and an optical network system that can reduce the cost and power consumption of the network and suppress delays.

[0021] 1 is a configuration diagram showing an optical wavelength conversion cross connect device according to an embodiment of the present invention. FIG. 1 is a configuration diagram showing an optical wavelength conversion cross connect device according to an embodiment of the present invention. FIG. 2 is a diagram showing an example configuration of a wavelength conversion functional unit included in an optical wavelength conversion cross connect device according to an embodiment of the present invention. FIG. 3 is a diagram showing optical communication wavelength bands used in an optical network system according to an embodiment of the present invention. FIG. 4 is a diagram showing a collective wavelength band conversion function of a wavelength conversion functional unit of an optical wavelength conversion cross connect device according to an embodiment of the present invention. FIG. 5 is a diagram showing an individual wavelength conversion function of a wavelength conversion functional unit of an optical wavelength conversion cross connect device according to an embodiment of the present invention. FIG. 6 is a diagram showing a defragmentation function of a wavelength conversion functional unit of an optical wavelength conversion cross connect device according to an embodiment of the present invention. FIG. 7 is a diagram showing a configuration for connecting a wavelength conversion functional unit according to an embodiment of the present invention to an optical cross connect device. FIG. 8 is a diagram showing an example relationship between optical communication links and wavelength bands in multi-band networking technology. FIG. 9 is a diagram showing a schematic configuration of an optical network system using an optical wavelength conversion cross connect device according to an embodiment of the present invention. FIG. 10 is a diagram showing a schematic configuration of an optical network system including an optical wavelength conversion cross connect device according to an embodiment of the present invention. Fig. 15 is a diagram showing the configuration of a wavelength multiplexing transmission system equipped with a wavelength cross-connect device described in Non-Patent Document 1. Fig. 16 is a diagram showing a schematic configuration of an optical network system using the technology of the wavelength multiplexing optical transmission system of Fig. 14. Fig. 17 is a diagram explaining an optical path switching method of a conventional optical network system.

[0022] An optical network system and the like in an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described below with reference to the drawings. (Embodiment) Figures 1 and 2 are block diagrams showing an optical wavelength conversion cross-connect device according to an embodiment of the present invention. Components that are the same as those in Figure 16 are assigned the same reference numerals.

[0023] [Optical Wavelength Conversion Cross Connect Device] The optical wavelength conversion cross connect devices 100 and 100A according to the embodiments of the present invention are optical cross connect devices (OXCs) that are connected to optical fibers of a path that bundles together a plurality of optical fibers as a relay node for optical signals. The optical wavelength conversion cross connect devices 100 and 100A can be replaced with an existing optical cross connect device (OXC) 10.

[0024] In the optical wavelength converting cross-connect device 100, a wavelength conversion function unit 110 (described later) converts a specific wavelength band in the optical communication wavelength band into another specific wavelength band in a lump (FIG. 1). Also, the optical wavelength converting cross-connect device 100A converts signal wavelengths in a specific wavelength band in the optical communication wavelength band into signal wavelengths in another specific wavelength band individually (FIG. 2). The configurations will be described below in order.

[0025] <Wavelength conversion function unit 110 for batch wavelength conversion> The optical wavelength conversion cross-connect device 100 shown in FIG. 1 includes an optical cross-connect device (OXC) 10 and a wavelength conversion function unit 110. １ , 110 ２ (Wavelength conversion function unit 110 １ , 110 ２ The optical wavelength converting cross-connect device 100 includes a wavelength converting function unit 110 (which will be collectively referred to as a wavelength converting function unit 110). That is, the optical wavelength converting cross-connect device 100 has a configuration in which the wavelength converting function unit 110 is added to the optical cross-connect device (OXC) 10 shown in FIG. 16. The detailed configuration of the optical wavelength converting cross-connect device 100 will be described later with reference to FIG. 8. The detailed configuration of the wavelength converting function unit 110 will be described later with reference to FIG. 3.

[0026] The wavelength conversion function unit 110 converts the wavelength of the wavelength-multiplexed signal light that is route-switched by the optical cross-connect device (OXC) 10 (optical cross-connect function unit). The wavelength conversion function unit 110 can use, for example, the all-optical wavelength band conversion technology described in Non-Patent Document 2. The wavelength conversion function described in Non-Patent Document 2 can convert a specific wavelength band, and therefore can be used for wavelength band conversion. The wavelength conversion function unit 110 shown in FIG. １ , λcn (C-band) optical signals into optical signals having wavelengths λcL1, ..., λcLn (L-band). ２converts optical signals of wavelengths λL1, . . . , λLn (L band) into optical signals of wavelengths λLc1, .

[0027] The optical cross-connect device (OXC) 10 shown in FIG. 1 includes an add-on wavelength conversion function unit 110. １ , λcn (C-band)) of the path 1 is wavelength-converted into a wavelength-division multiplexed (WDM) signal (wavelengths λcL1, λcLn (L-band)) and switched to the path 2. The optical cross-connect device (OXC) 10 shown in FIG. 1 also includes an add-on wavelength conversion function unit 110. ２ , λLn (L band)) of the path 2 is wavelength-converted into wavelength-multiplexed signals (wavelengths λc1, . . . , λcn (C band)) all at once, and then switched to the path 1.

[0028] <Wavelength Conversion Function Unit 110 for Individual Wavelength Conversion> The optical wavelength conversion cross-connect device 100A shown in FIG. 2 includes an optical cross-connect device (OXC) 10, an Add / Drop function unit 12, and a wavelength conversion function unit 110. １ , 110 ２ That is, when the optical cross-connect device (OXC) 10 shown in FIG. 16 is provided with an add / drop device (add / drop function unit 12), the optical wavelength converting cross-connect device 100 has a wavelength converting function unit 110 below the add / drop device. １ , 110 ２ The optical wavelength conversion cross-connect device 100A has an add-on configuration. The detailed configuration of the optical wavelength conversion cross-connect device 100A will be described later with reference to FIG. 9. The conversion of individual wavelength signals can use the Optical-Analog-Optical (OAO) method described in Non-Patent Document 3. Non-Patent Document 3 focuses on the Optical-Analog-Optical (OAO) method and realizes OAO wavelength conversion by combining coherent detection and IQ modulation. The add / drop functional unit 12 performs processing to add, drop, or pass through optical signals to wavelength-multiplexed signal light obtained by multiplexing optical signals.

[0029] The wavelength conversion function unit 110 shown in FIG. １converts a specific optical signal wavelength (here, wavelength λc1) added or dropped by the add / drop functional unit 12 into a specific optical signal wavelength (here, wavelength λLc1) and transmits the converted optical signal to the add / drop functional unit 12. In addition, the wavelength conversion functional unit 110 shown in FIG. ２ converts the specific optical signal wavelength (here, wavelength λL1) added or dropped by the Add / Drop functional unit 12 into a specific optical signal wavelength (here, wavelength λLc1) and sends it to the Add / Drop functional unit 12.

[0030] The optical cross-connect device (OXC) 10 shown in FIG. 2 includes a wavelength conversion function unit 110. １ The optical cross-connect device (OXC) 10 shown in FIG. 2 receives the specific optical signal wavelength (wavelength λcL1) wavelength-converted by the wavelength conversion function unit 110 via the Add / Drop function unit 12 and switches it to the path 2. ２ receives the wavelength-converted specific optical signal wavelength (wavelength λcL1) via the Add / Drop functional unit 12 and switches it to the path 2.

[0031] <Wavelength Conversion Functional Unit 110> The all-optical wavelength band conversion technology described in Non-Patent Document 2 will be described. FIG. 3 is a diagram showing an example of the configuration of the wavelength conversion functional unit 110 included in the optical wavelength conversion cross-connect devices 100 and 100A shown in FIGS. 1 and 2. The wavelength conversion functional unit 110 shown in FIG. 3 is an all-optical wavelength conversion unit that performs wavelength band conversion in a lump from a specific wavelength band in the optical communication wavelength band (see FIG. 4) to another specific wavelength band. As shown in FIG. 3, the wavelength conversion functional unit (all-optical wavelength conversion unit) 110 includes a pumping light source 111, an optical fiber 112A, an optical multiplexer 113, a nonlinear optical medium 114, an optical demultiplexer 115 (wavelength separation unit), and an optical fiber 112B. The wavelength conversion functional unit 110 is an all-optical wavelength conversion device that includes a nonlinear optical medium 114 onto which both the optical main signal to be relayed and the pumping light emitted from the pumping light source 111 can be simultaneously incident.

[0032] The pumping light source 111 generates pumping light Oe having a predetermined wavelength λe. The pumping light Oe generated by the pumping light source 111 passes through an optical fiber 112A and enters the optical multiplexer 113. The wavelength λe of the pumping light Oe is different from the wavelength λ1 of the input optical signal Oin. The optical intensity of the pumping light Oe is sufficiently greater than that of the input optical signal Oin.

[0033] The optical multiplexer 113 generates light by multiplexing the input optical signal Oin (C band) input from the optical fiber cable 112 and the pump light Oe input from the optical fiber 112A, and sends it to the input end of the nonlinear optical medium 114.

[0034] The nonlinear optical medium 114 has nonlinear optical properties and can generate an optical signal with a wavelength different from that of the incident light. As a representative example, any one of highly nonlinear fiber (HNLF), periodically poled lithium niobate (PPLN), and semiconductor optical amplifier (SOA) can be used as the nonlinear optical medium 114. In FIG. 3 , the nonlinear optical medium 114 generates an optical signal (L band) with a wavelength different from that of the incident light (C band).

[0035] The optical demultiplexer 115 is connected to the light output side of the nonlinear optical medium 114, which is an all-optical wavelength conversion device. The output light Oout output from the output end of the nonlinear optical medium 114 is input to the optical demultiplexer 115. The optical demultiplexer 115 demultiplexes the incident light using its wavelength selection characteristics and extracts two types of optical signals (L band and C band). That is, an outgoing optical signal Oo2 with wavelength λ2 (wavelength-converted light; L band) and an output light Oo1 with wavelength λ1 (original wavelength light; C band) are output from different output terminals of the optical demultiplexer 115.

[0036] The wavelength λ2 of the outgoing optical signal Oo2 is generated based on the wavelength of the input optical signal Oin, the wavelength λe of the pumping light Oe, and the nonlinear optical characteristics of the nonlinear optical medium 114. The input optical signal Oin with wavelength λ1 passes through the nonlinear optical medium 114 together with the pumping light Oe, thereby generating the wavelength λ2 (L band) of the wavelength-converted outgoing optical signal Oo2. The light emitted from the nonlinear optical medium 114 also contains an optical component with the same wavelength λ1 (C band) as before the wavelength conversion.

[0037] The outgoing optical signal Oo2 of wavelength λ2 output from the optical demultiplexer 115 is transmitted as a relay output from the output of the optical wavelength conversion cross connect device 100 to the downstream optical fiber cable 112. In addition, the outgoing light Oo1 of wavelength λ1 output from the optical demultiplexer 115 is input to the detector 116 in the optical wavelength conversion cross connect device 100 via the optical fiber 112B.

[0038] In this way, by utilizing the wavelength conversion functional unit (all-optical wavelength conversion unit) 110 shown in FIG. 3, the wavelength of the optical main signal relayed by the optical wavelength conversion cross connect device 100 can be converted from λ1 to λ2 without electrical termination, thereby preventing an increase in delay. Furthermore, the output light Oo1 having the same wavelength λ1 as before wavelength conversion, i.e., unnecessary optical components other than the main signal, can be input to the detector 116. The detector 116 internally converts the input output light Oo1 having the wavelength λ1 into an electrical signal and can perform various processes in the form of an electrical signal. This allows transmission quality data to be obtained at the relay node positions of the optical wavelength conversion cross connect device 100.

[0039] <Optical Communication Wavelength Band> Figure 4 is a diagram showing the optical communication wavelength band used in the optical network system 1000. As shown in Figure 4, the optical communication wavelength band is a wavelength band used when performing optical communication. Optical communication uses optical fiber as a transmission path. For this reason, the wavelength band of 1000 nm to 1675 nm among the wavelengths of electromagnetic waves is used, taking into account factors such as transmission loss of the optical fiber. The wavelength band is further subdivided and is called, in order from shortest wavelength, the T-band (Thousand-band), O-band (Original-band), E-band (Extended-band), S-band (Short-wavelength-band), C-band (Conventional-band), L-band (Long-wavelength-band), and U-band (Ultralong-wavelength-band). The bands and wavelengths are T-band 1000 to 1260 nm, O-band 1260 to 1360 nm, E-band 1360 to 1460 nm, S-band 1460 to 1530 nm, C-band 1530 to 1565 nm, L-band 1565 to 1625 nm, and U-band 1625 to 1675 nm. The wavelength conversion function unit 110 of the optical wavelength conversion cross-connect devices 100 and 100A (FIGS. 1 and 2) covers all of the optical communication wavelength bands shown in FIG. 4 as convertible wavelength bands.

[0040] <Function of Wavelength Conversion Functional Unit 110> Figures 5 to 7 are diagrams showing the function of the wavelength conversion functional unit 110. Figure 5 is a diagram showing the batch wavelength band conversion function of the wavelength conversion functional unit 110 of Figure 1. As indicated by the white arrow aa in Figure 5, the wavelength conversion functional unit 110 of Figure 1 performs batch wavelength band conversion of wavelength multiplexed signals of wavelengths λc1, λc2, and λc3 (C band) into wavelength multiplexed signals of wavelengths λL1, λL2, and λL3 (L band). In the optical wavelength conversion cross-connect device 100 of Figure 1, the wavelength conversion functional unit 110 is capable of batch wavelength band conversion.

[0041] Fig. 6 is a diagram showing the individual wavelength conversion function of the wavelength conversion functional unit 110 of Fig. 2. As indicated by the white arrows bb in Fig. 6, the wavelength conversion functional unit 110 of Fig. 2 individually converts wavelength-multiplexed signals of wavelengths λc1, λc2, and λc3 (C band) into an optical signal wavelength of wavelength λS2 (S band). In the optical wavelength conversion cross-connect device 100A of Fig. 2, the wavelength conversion functional unit 110 is capable of individual wavelength conversion. As described above, the optical wavelength conversion cross-connect devices 100 and 100A of this embodiment are capable of both wavelength conversion functions: batch wavelength band conversion and individual wavelength wavelength conversion.

[0042] Figure 7 is a diagram showing the defragmentation function of the wavelength conversion function unit 110 in Figure 2. One effective use of the wavelength conversion function of the wavelength conversion function unit 110 is to optimize the fragmentation of signal wavelengths (referred to as the "defragmentation function"). As shown in Figure 7, when discrete wavelength-multiplexed signals of λc1, λc3, λc8, and λc10 are present, λc8 is wavelength-converted to λc2 (white arrow cc in Figure 7) and λc10 is wavelength-converted to λc4 (white arrow dd in Figure 7) to improve the efficiency of the wavelength band. This allows the signal wavelength band to be made more efficient.

[0043] <Implementation of Optical Wavelength Conversion Cross Connect Device> A specific configuration for connecting the wavelength conversion function unit 110 in Fig. 1 and Fig. 2 to the optical cross connect device (OXC) 10 will be described. Fig. 8 is a diagram showing a configuration for connecting the wavelength conversion function unit 110 in Fig. 1 to the optical cross connect device (OXC) 10. The optical wavelength conversion cross connect device 100 shown in Fig. 8 is configured by the optical cross connect device (OXC) 10 and the wavelength conversion function unit 110. １ , 110 ２The optical cross-connect device (OXC) 10 includes wavelength selective switches (WSSs) 21 (WSS#1) and 22 (WSS#2) arranged opposite each other on the input side, and WSSs 23 (WSS#1) and 24 (WSS#2) on the output side connected to WSSs 21 (WSS#1) and 22 (WSS#2). WSSs 21 to 24 are optical switches that demultiplex input multiplexed wavelengths and switch them to any route. WSSs 21 to 24 each have one input port and N (e.g., six) output ports.

[0044] The input side WSS 21 (WSS #1) connected to the path 1 (C band) is connected to the output side WSS 23 (WSS #1) connected to the output side path 1 (C band) and the output side WSS 24 (WSS #2) connected to the output side path 2 (L band). In addition to the existing connection paths connected to the output side WSS 23 (WSS #1) connected to the output side path 1 (C band) and the output side WSS 24 (WSS #2) connected to the output side path 2 (L band), a wavelength conversion function unit 110 added to the OXC 10 is added. １ The wavelength conversion function unit 110 shown in FIG. １ wavelength conversion functional unit 110 converts optical signals of wavelengths λc1, ..., λcn (C band) into optical signals of wavelengths λcL1, ..., λcLn (L band). １ is connected to an output WSS 24 (WSS#2) connected to the path 2 (L band) on the output side of the OXC 10, and outputs a wavelength multiplexed signal of wavelengths λcL1, ..., λcLn (L band) that have been subjected to simultaneous wavelength band conversion to the WSS 24 (WSS#2). The WSS 24 (WSS#2) is a wavelength conversion functional unit 110 １ When the above is used (when the output port recombination is changed by an instruction from a network controller or the like, not shown), wavelength multiplexed signals of collectively wavelength band converted wavelengths λcL1, . . . , λcLn (L band) are output.

[0045] Similarly, the input-side WSS 22 (WSS #2) connected to the route 2 (L band) is connected to the output-side WSS 23 (WSS #1) connected to the output-side route 1 (C band) and the output-side WSS 24 (WSS #2) connected to the output-side route 2 (L band), in addition to the existing connection paths connected to the output-side WSS 23 (WSS #1) connected to the output-side route 1 (C band) and the output-side WSS 24 (WSS #2) connected to the output-side route 2 (L band), and the wavelength conversion function unit 110 added to the OXC 10. ２The wavelength conversion function unit 110 shown in FIG. ２ The wavelength conversion functional unit 110 converts optical signals with wavelengths λL1, ..., λLn (L band) into optical signals with wavelengths λLc1, ..., λLcn (C band). ２ is connected to an output WSS 23 (WSS#1) connected to the output path 1 (C band) of the OXC 10, and outputs a wavelength multiplexed signal of wavelengths λLc1, ..., λLcn (C band) that have been subjected to simultaneous wavelength band conversion to the WSS 23 (WSS#1). The WSS 23 (WSS#1) is a wavelength conversion function unit 110. １ When using the above, wavelength multiplexed signals of wavelengths λLc1, . . . , λLcn (C band) that have been simultaneously wavelength band converted are output.

[0046] The optical wavelength conversion cross-connect device 100 shown in Figure 8 performs collective wavelength conversion of wavelength-multiplexed signals on path 1 from the C band to the L band and switches them to path 2. The optical wavelength conversion cross-connect device 100 also performs collective wavelength conversion of wavelength-multiplexed signals on path 2 from the L band to the C band and switches them to path 1. It is assumed that path 1 is connected to an optical transmission line for the C band, such as SMF, and path 2 is connected to a transmission line for the L band, such as DSF. With this configuration, WSSs 21 to 24 can wavelength-convert only wavelengths in a partial band of the wavelength-multiplexed signal on path 1 and switch it to path N by changing the switch settings.

[0047] 9 is a diagram showing an example of a configuration in which the wavelength conversion function unit 110 in FIG. 2 is connected to an optical cross-connect device (OXC) 10. The same components as those in FIG. 8 are assigned the same reference numerals. The optical wavelength conversion cross-connect device 100A shown in FIG. 9 includes an optical cross-connect device (OXC) 10A and a wavelength conversion function unit 110. １ , 110 ２The optical cross-connect device (OXC) 10A includes WSS 21 (WSS#1) and WSS 22 (WSS#2) arranged opposite to each other on the input side, WSS 23 (WSS#1) and WSS 24 (WSS#2) on the output side connected to WSS 21 (WSS#1) and WSS 22 (WSS#2), and an N×M WSS 25. The N×M WSS 25 is a multicast switch having a 1×N splitter that branches an input signal into N and an M×1 switch that switches the 1×N splitter output. The N×M WSS 25 has an add / drop function that adds / drops optical signals transmitted through each of the paths 1 and 2 for each wavelength.

[0048] The input WSS 21 (WSS #1) connected to the path 1 (C band) is connected to an N×M WSS 25 in addition to the existing connection paths connecting the output WSS 23 (WSS #1) connected to the output path 1 (C band) and the output WSS 24 (WSS #2) connected to the output path 2 (L band). Similarly, the input WSS 22 (WSS #2) connected to the path 2 (L band) is connected to an N×M WSS 25 in addition to the existing connection paths connecting the output WSS 23 (WSS #1) connected to the output path 1 (C band) and the output WSS 24 (WSS #2) connected to the output path 2 (L band).

[0049] The N×M WSS 25 adds / drops optical signals from WSSs 21 to 24 for each wavelength. Here, the N×M WSS 25 demultiplexes (drops) an optical signal of an arbitrary wavelength (for example, wavelength λc1) from optical signals of wavelengths λc1, ..., λcn (C band) from the input side WSS 21 (WSS #1) connected to route 1 (C band). The wavelength conversion function unit 110 shown in FIG. １ The wavelength conversion unit 110 converts the optical signal of wavelength λc1 into an optical signal of wavelength λcL1 (L band) and outputs the converted signal to the N×M WSS 25. The N×M WSS 25 has a wavelength conversion function unit 110. １ The N×M WSS 25 adds an optical signal with wavelength λcL1 converted by the wavelength conversion function unit 110. １ outputs the wavelength-band-converted wavelength multiplexed signal of wavelength λcL1 (L band) to WSS 24 (WSS#2).

[0050] Similarly, the N×M WSS 25 demultiplexes (drops) an optical signal of an arbitrary wavelength (for example, wavelength λL1) from among optical signals of wavelengths λL1, ..., λLn (L band) from the input-side WSS 22 (WSS #2) connected to path 2 (L band). ２ The wavelength conversion unit 110 converts the optical signal of wavelength λL1 into an optical signal of wavelength λLc1 (C band) and outputs the converted signal to the N×M WSS 25. The N×M WSS 25 has a wavelength conversion function unit 110. ２ The N×M WSS 25 adds an optical signal with a wavelength λLc1 converted by the wavelength conversion function unit 110. ２ outputs the wavelength-band-converted wavelength multiplexed signal of wavelength λLc1 (C band) to WSS 23 (WSS#1).

[0051] The optical wavelength conversion cross-connect device 100A shown in FIG. 9 has a wavelength conversion function unit 110 under the control of an N×M WSS 25. １ , 110 ２ The optical wavelength conversion cross-connect device 100A wavelength-converts an optical signal λc1 of the first path to λcL1 of the second path, and also wavelength-converts an optical signal λL1 of the second path to λLc1 of the first path.

[0052] [Optical Network System] <Multiband Networking Technology> Figure 10 is a diagram showing an example of the relationship between optical communication links and wavelength bands in multiband networking technology. As shown in Figure 10, it is assumed that there are three types of optical wavelength bands used for communication: L-band, C-band, and S-band. The L-band is a wavelength band from 1565 to 1625 nm. The C-band is a wavelength band from 1530 to 1565 nm. The S-band is a wavelength band from 1460 to 1530 nm. Furthermore, the L-band, C-band, and S-band each have an optical path that is independent of each other. The example in Figure 10 also assumes the presence of two optical communication links 31 and 32 that are independent of each other.

[0053] The optical signals of each optical communication link 31, 32 are adaptively band-switched according to the situation, and are switched across optical paths of multiple bands. The optical signal of the optical communication link 31 shown in Figure 10 passes through an L-band optical path, is converted to a C-band optical signal by wavelength conversion, enters the C-band optical path, and is further converted to an S-band optical signal by wavelength conversion, enters the S-band optical path. This light is then converted to an L-band optical signal by wavelength conversion, enters the L-band optical path, and is converted to an electrical signal in a Ph-EX (Photonic Exchange), processed, and output. The Ph-EX is a component that minimizes electrical processing such as exchange, multiplexing, and switching.

[0054] In addition, an optical signal of the optical communication link 32 having a C-band wavelength passes through a C-band optical path, is converted into an S-band optical signal by wavelength conversion, enters the S-band optical path, and is converted into an electrical signal by Ph-EX for processing.

[0055] By utilizing the technology shown in Figure 10, optical transmission systems can efficiently use limited wavelength resources. Furthermore, because electrical termination processing can be omitted at each communication node and optical signals can be processed as they are, benefits such as reduced power consumption, increased capacity, and reduced latency can be expected for the network. However, the optical transmission equipment at each node must be equipped with a function to convert the wavelength of optical signals.

[0056] <Application Example 1 of Optical Network System> Application Example 1 is an example in which the present optical network system is introduced into the multiband networking technology of FIG. 10. FIG. 11 is a diagram showing a schematic configuration of an optical network system 1000 that uses the multiband networking technology of FIG. 10 and the optical wavelength conversion cross-connect devices 100, 100A1, 100A2, and 100A3 of FIGS. 1 and 2. Components identical to those in FIG. 15 are designated by the same reference numerals. The optical network system 1000 shown in FIG. 11 comprises optical wavelength conversion cross-connect devices 100, 100A1, 100A2, and 100A3 and an optical cross-connect device (OXC) 10 as nodes, constituting a ROADM system that enables optical signal drop and addition at each node. An IP router 14 is connected to the optical wavelength conversion cross-connect devices 100A1 and 100A2 via a wavelength conversion function unit 110. In FIG. 11, for the sake of convenience, the add / drop function unit 12 and the wavelength conversion function unit 110 are shown outside the optical cross-connect device (OXC) 10.

[0057] The optical network system 1000 includes optical wavelength conversion cross-connect devices 100, 100A1, 100A2, and 100A3 and an optical cross-connect device (OXC) 10, and can switch any optical wavelength (optical path) to a different route, thereby configuring a mesh optical network. For example, when it is necessary to convert a C-band optical wavelength signal (wavelength λ1) to an L-band optical wavelength signal (wavelength λ2) in the optical wavelength conversion cross-connect device 100A1, the OXC 10 in FIG. １１ Instead, by applying the optical wavelength conversion cross-connect device 100A1, it becomes possible to convert from C-band to L-band signals without converting to electrical signals, thereby avoiding the degradation of transmission characteristics in DSF.

[0058] In addition, in the optical wavelength conversion cross-connect device 100A2, when it is necessary to convert, for example, an S-band optical wavelength signal (wavelength λ3) into an L-band optical wavelength signal (wavelength λ2), the OXC 10 shown in FIG. Ｎ１15. In place of the OXC 10 shown in FIG. 15, if an optical wavelength conversion cross-connect device 100A2 is applied, it becomes possible to convert from S band to L band signals without converting to electrical signals. ２１ 15. In place of the above, the optical wavelength conversion cross-connect device 100 is applied. ２Ｍ 1 shows an example in which an optical wavelength conversion cross-connect device 100A3 is applied instead of the above.

[0059] In this way, the optical wavelength converting cross-connect devices 100, 100A1, 100A2, and 100A3 can be realized simply by adding the wavelength conversion function unit 110 to the conventional optical cross-connect device 10. The optical wavelength converting cross-connect devices 100, 100A1, 100A2, and 100A3 do not use optical transceivers (transponders), and therefore enable power-saving, low-latency wavelength conversion.

[0060] <Application Example 2 of Optical Network System> Application Example 2 is an example in which a C-band optical wavelength signal is converted into an L-band optical wavelength signal in an optical network system. FIG. 12 is a diagram showing a schematic configuration of an optical network system 1000 including the optical wavelength conversion cross-connect device 100 of FIG. 1. Components identical to those in FIG. 11 are assigned the same reference numerals. The optical network system 1000 shown in FIG. 12 includes OXCs <1> to <6> as optical nodes. Of OXCs <1> to <6>, OXCs <1>, <3>, <4>, and <6> are the existing OXC 10, and OXCs <2> and <5> are the optical wavelength conversion cross-connect device 100 of FIG. 1. As described above, the optical wavelength conversion cross-connect device 100 (OXCs <2> and <5>) has a wavelength conversion function unit 110 added to the OXC 10.

[0061] OXC<1>, OXC<2> (optical wavelength conversion cross-connect device 100), OXC<4>, and OXC<5> (optical wavelength conversion cross-connect device 100) are connected by a C-band transmission line such as single mode fiber (SMF). Also, OXC<2> (optical wavelength conversion cross-connect device 100), OXC<3>, OXC<5> (optical wavelength conversion cross-connect device 100), and OXC<6> are connected by an L-band transmission line such as dispersion shifted fiber (DSF).

[0062] The optical network system 1000 of FIG. 12 uses SMF and DSF. In DSF, the transmission characteristics of C-band optical wavelength signals degrade due to the nonlinear effect of optical fiber. For this reason, L-band optical wavelength signals are used. When a C-band optical wavelength signal is transmitted through an SMF optical fiber transmission line (the transmission line connecting OXC<1>, OXC<2>, OXC<4>, and OXC<5>), the optical fiber transmission line from OXC<2> to OXC<3> is DSF, so the signal must be converted to an L-band optical wavelength signal. In this embodiment, the optical wavelength conversion cross-connect device 100 is applied to OXC<2>, enabling conversion from C-band to L-band signals without converting to electrical signals. This avoids degradation of transmission characteristics in DSF. In this case, a batch wavelength band converter (FIG. 1) is appropriate for the wavelength conversion function unit 110.

[0063] <Application Example 3 of Optical Network System> Application Example 3 is an extended example of the optical network system. FIG. 13 is a diagram showing a schematic configuration of an optical network system 1000 including the optical wavelength converting cross-connect device 100 of FIG. 1. The same components as those in FIG. 12 are assigned the same reference numerals. The optical network system 1000 shown in FIG. 13 includes OXCs <1>, <2>, <4>, and <5> as optical nodes. OXCs <1>, <2>, <4>, and <5> are the optical wavelength converting cross-connect devices 100 of FIG. 1. As described above, in the optical wavelength converting cross-connect devices 100 (OXCs <1>, <2>, <4>, and <5>), a wavelength conversion function unit 110 is added to the OXC 10.

[0064] The optical wavelength conversion cross-connect devices 100 (OXC<1>, <2>, <4>, <5>) are connected by SMF optical fiber transmission lines shown by solid lines in FIG. 13, and transmit C-band optical wavelength signals.

[0065] In the above configuration, the network is expanded by adding an existing optical cross-connect device (OXC) 10. In Fig. 13, OXCa to OXCd are added as OXCs 10 to expand the network (see the dashed lines in Fig. 13). The type of fiber connecting OXCa to OXCd is, for example, DSF.

[0066] In the optical network system 1000, optical wavelength conversion cross-connect devices 100 (OXCs <1>, <2>, <4>, and <5>) are connected via SMF. When the fiber type of the OXCs OXCa to OXCd to be expanded is DSF, conventionally, optical transmission is required to be performed by terminating the signal at a first transponder (TRPD) and then connecting it to a second transponder (TRPD) that generates a signal with an optical wavelength appropriate for a different destination fiber. In contrast, in this embodiment, by using the optical wavelength conversion cross-connect device 100 instead of the existing OXC 10, the optical network can be expanded without using expensive optical transmitters and receivers, even if the fiber type of the OXCs OXCa to OXCd to be expanded is DSF. Furthermore, by eliminating the need for a DSP installed in a conventional TRPD, power consumption and delay time can be reduced.

[0067] [Effects] As described above, the optical wavelength conversion cross-connect device 100, 100A (FIGS. 1, 2, 8, 9) connects input routes and output routes, and includes an optical cross-connect device (OXC) 10 that switches the wavelength-multiplexed signal light, which is obtained by multiplexing optical signals of multiple wavelength bands input from the input routes, for each route using a WSS and outputs the signal to an output route, and a wavelength conversion function unit 110 (FIGS. 1, 2, 8, 9) that converts the wavelength of the wavelength-multiplexed signal light whose route is switched by the optical cross-connect device (OXC) 10.

[0068] In this way, the optical wavelength converting cross-connect device 100, 100A can be added to an existing optical cross-connect device (OXC) 10, so that part or all of the existing optical cross-connect device (OXC) 10 constituting a relay node can be appropriately replaced with the optical wavelength converting cross-connect device 100, 100A. Therefore, it can be implemented universally without requiring a change in the design of the entire system. In addition, the optical network can be easily expanded.

[0069] The optical wavelength conversion cross-connect devices 100 and 100A can change the signal wavelength of the optical path without using an optical transceiver (transponder) when switching an optical path to a different route in the optical cross-connect device (OXC) 10. This allows for the reduction of the DSP installed in the transponder, thereby reducing power consumption and delay time.

[0070] For example, in the SMF optical fiber transmission line shown in Figure 12, applying the optical wavelength conversion cross-connect device 100 to OXCs <2> and <5> enables conversion from C-band to L-band signals without converting to electrical signals, thereby avoiding the degradation of transmission characteristics in DSF. Furthermore, conventional optical networks can be easily expanded. Furthermore, as shown in Figure 13, when expanding the network by adding OXCs (OXCa-OXCd), even if the type of fiber being expanded is DSF, applying the optical wavelength conversion cross-connect device 100, 100A to the existing OXCs enables the optical network to be expanded without using expensive optical transmitters and receivers.

[0071] In the optical wavelength conversion cross-connect devices 100, 100A (FIGS. 1, 2, 8, and 9), the wavelength conversion functional unit 110 converts a specific wavelength band in the optical communication wavelength band into another specific wavelength band all at once (FIG. 5), or converts an optical signal wavelength in a specific wavelength band in the optical communication wavelength band into a signal wavelength in another specific wavelength band individually (FIG. 6).

[0072] In this manner, the wavelength conversion functional unit 110 can perform conversions in units of one wavelength or multiple wavelengths. That is, the wavelength conversion functional unit 110 can perform both batch wavelength band conversion and individual wavelength conversion. As an example of batch wavelength band conversion, as shown in FIG. 8, the wavelength-multiplexed signal of path 1 is batch wavelength-converted from the C band to the L band and switched to path 2, and the wavelength-multiplexed signal of path 2 is batch wavelength-converted from the L band to the C band and switched to path 1. As an example of individual wavelength conversion, as shown in FIG. 9, the optical wavelength conversion cross-connect device 100A wavelength-converts a specific optical signal wavelength (in FIG. 9, the optical signal λc1 of path 1 is wavelength-converted to the λcL1 of path 1, and the optical signal λL1 of path 2 is wavelength-converted to the λLc1 of path 1).

[0073] In the optical wavelength converting cross connect devices 100, 100A (FIGS. 1, 2, 8, and 9), the optical cross connect device (OXC) 10 optimizes the fragmentation of the optical signal wavelength converted by the wavelength converting function unit 110 (FIG. 7).

[0074] In this way, optimizing the fragmentation of signal wavelengths is effective. As shown in Figure 7, when there are discrete wavelength-multiplexed signals of λc1, λc3, λc8, and λc10, the signal wavelength band can be made more efficient by wavelength-converting λc8 to λc2 and λc10 to λc4.

[0075] The optical wavelength conversion cross-connect device 100A (FIGS. 2 and 9) includes an add / drop functional unit 12 that performs processing to add, drop, or pass optical signals to wavelength-multiplexed signal light obtained by multiplexing optical signals.

[0076] In this way, the add / drop functional unit 12 can perform processing to add, drop, or pass an optical signal to a wavelength-multiplexed signal light obtained by multiplexing optical signals. Note that the optical signal wavelength may or may not pass through the optical add / drop functional unit 12. An optical path that requires wavelength conversion can pass through the wavelength conversion functional unit 110 and be converted to any optical wavelength.

[0077] In the optical wavelength conversion cross-connect device 100A (FIGS. 2 and 9), the add / drop functional unit 12 (FIG. 2) adds or drops a specific optical signal wavelength from the wavelength-multiplexed signal light transmitted by the optical cross-connect device (OXC) 10, and the wavelength conversion functional unit 110 wavelength-converts the optical signal wavelength added or dropped by the add / drop functional unit 12 to another optical signal wavelength and sends it to the add / drop functional unit 12.

[0078] In this way, the optical cross connect device (OXC) 10 and the wavelength conversion functional unit 110 can wavelength convert a specific optical signal wavelength without using an optical transceiver (transponder) when switching an optical path to a different route in the optical cross connect device (OXC) 10, by working in cooperation with the add / drop functional unit 12. This makes it possible to reduce the number of DSPs (Digital Signal Processors) installed in the transponder, thereby reducing power consumption and delay time.

[0079] In the optical wavelength conversion cross-connect devices 100, 100A (Figures 1, 2, 8, and 9), the wavelength conversion function unit 110 has an excitation light source 111 (Figure 3) that emits excitation light of a wavelength different from the wavelength of the wavelength-multiplexed signal light before wavelength conversion, a nonlinear optical medium 114 (Figure 3) that can simultaneously receive both the wavelength-multiplexed signal light and the excitation light emitted from the excitation light source 111, and a wavelength separation unit (optical demultiplexer 115) (Figure 3) that separates the light emitted from the nonlinear optical medium 114 into an optical component with a wavelength after wavelength conversion and an optical component with a wavelength before wavelength conversion.

[0080] By doing so, the optical intensity of the wavelength-converted signal light component contained in the output light Oout (FIG. 3) from the nonlinear optical medium 114 depends on the nonlinear optical medium 114 and the pump light intensity, and can be made equivalent to that of the input optical signal Oin. Therefore, wavelength conversion can be performed without attenuating the optical intensity. Furthermore, the optical intensity of the optical components of wavelengths λ1 to λ2 contained in the output light Oout is equivalent to that of the input optical signal Oin. Therefore, optical signals other than the main signal, which have the same wavelengths λ1 to λ2 as before wavelength conversion, can be extracted from the output of the nonlinear optical medium 114 with sufficiently high optical intensity.

[0081] In the optical wavelength conversion cross-connect devices 100, 100A (Figures 1, 2, 8, and 9), the wavelength conversion function unit 110 converts wavelengths in the optical communication wavelength bands T-band (Thousand-band), O-band (Original-band), E-band (Extended-band), S-band (Short-wavelength-band), C-band (Conventional-band), L-band (Long-wavelength-band), or U-band (Ultralong-wavelength-band) (Figure 4).

[0082] By doing so, the wavelength bands that the wavelength conversion functional unit 110 of the optical wavelength conversion cross-connect device 100, 100A can convert can cover all of the optical communication wavelength bands shown in FIG. 4. For example, if the wavelength-multiplexed signal light is a multiplexed version of optical signals in the S, C, and L bands, the S, C, and L bands can be assigned to the S, C, and L bands of the optical fiber serving as the transmission path during transmission. Furthermore, the technological maturity of optical devices is highest for the C band, which is most commonly used in general optical transmission systems, followed by the L band, the S band, and the E band and below, which have shorter wavelengths. Therefore, if optical devices for the S band or below, which require a technological maturity period, are realized, the optical wavelength conversion cross-connect device 100, 100A can support next-generation multi-bands by covering all optical communication wavelength bands, including the S, C, and L bands.

[0083] An optical network system 1000 (FIG. 11) includes optical wavelength conversion cross-connect devices 100, 100A (FIGS. 1, 2, 8, 9) that are connected as optical signal relay nodes to optical fibers of a route that bundles together a plurality of optical fibers. The optical wavelength conversion cross-connect devices 100, 100A include an optical cross-connect device (OXC) 10 that switches the direction of wavelength-multiplexed signal light, which is obtained by multiplexing optical signals of a plurality of wavelength bands input from an input route, for each route using a WSS and outputs the signal to an output route, and a wavelength conversion function unit 110 (FIGS. 1, 2, 8, 9) that converts the wavelength of the wavelength-multiplexed signal light whose direction is switched by the optical cross-connect device (OXC) 10.

[0084] By doing so, the optical network system 1000 can appropriately replace some or all of the existing optical cross-connect devices (OXCs) 10 constituting relay nodes with the optical wavelength conversion cross-connect devices 100, 100A. This allows for versatile implementation without requiring changes to the overall system design. Furthermore, the optical network can be easily expanded.

[0085] Furthermore, among the processes described in the above embodiments, all or part of the processes described as being performed automatically can be performed manually, or all or part of the processes described as being performed manually can be performed automatically using known methods. In addition, the processing procedures, control procedures, specific names, and information including various data and parameters shown in the above documents and drawings can be changed as desired unless otherwise specified. Furthermore, the components of each device shown in the drawings are functionally conceptual and do not necessarily have to be physically configured as shown. In other words, the specific form of distribution and integration of each device is not limited to that shown in the drawings, and all or part of the devices can be functionally or physically distributed and integrated in any unit depending on various loads, usage conditions, etc.

[0086] Furthermore, the above-described configurations, functions, processing units, processing means, etc. may be partially or entirely implemented in hardware, for example, by designing them as integrated circuits. The above-described configurations, functions, etc. may also be implemented by software that causes a processor to interpret and execute programs that implement the respective functions. Information such as programs, tables, and files that implement the respective functions may be stored in a memory, a recording device such as a hard disk or a solid-state drive (SSD), or a recording medium such as an integrated circuit (IC) card, a secure digital (SD) card, or an optical disk.

[0087] 10 Optical cross-connect device (OXC) (optical cross-connect function unit) 12 Add / Drop function unit 21 to 24 WSS 25 N×M WSS 31, 32 Optical communication link 100, 100A, 100A1, 100A2, 100A3 Optical wavelength conversion cross-connect device 110, 110 １ , 110 ２ Wavelength conversion function unit 111 Pumping light source 112A, 112B Optical fiber 113 Optical multiplexer 114 Nonlinear optical medium 115 Optical demultiplexer (wavelength separation unit) 1000 Optical network system

Claims

1. An optical wavelength conversion cross-connect device that connects input routes and output routes, comprising: an optical cross-connect function unit that switches wavelength-multiplexed signal light, which is obtained by multiplexing optical signals of multiple wavelength bands input from the input routes, for each route using a WSS (Wavelength Selective Switch) and outputs the signal light to the output route; and a wavelength conversion function unit that converts the wavelength of the wavelength-multiplexed signal light whose route is switched by the optical cross-connect function unit.

2. The optical wavelength conversion cross-connect device according to claim 1, characterized in that the wavelength conversion functional unit converts a specific wavelength band of an optical communication wavelength band, which is a plurality of wavelength bands, into another specific wavelength band, or converts an optical signal wavelength of a specific wavelength band of the optical communication wavelength band into a signal wavelength of another specific wavelength band individually.

3. The optical wavelength conversion cross-connect device according to claim 2, wherein said optical cross-connect function unit optimizes the fragmentation of said optical signal wavelengths wavelength-converted by said wavelength conversion function unit.

4. The optical wavelength conversion cross-connect device according to claim 1, further comprising an add / drop functional unit that performs processing to add, drop or pass optical signals to wavelength-multiplexed signal light obtained by multiplexing optical signals.

5. The optical wavelength conversion cross-connect device according to claim 4, wherein the Add / Drop functional unit adds or drops a specific optical signal wavelength from the wavelength multiplexed signal light transmitted by the optical cross-connect functional unit, and the wavelength conversion functional unit wavelength-converts the optical signal wavelength added or dropped by the Add / Drop functional unit to another optical signal wavelength and sends it to the Add / Drop functional unit.

6. The optical wavelength conversion cross-connect device according to claim 1, characterized in that the wavelength conversion function unit comprises: an excitation light source that emits excitation light of a wavelength different from the wavelength of the wavelength-multiplexed signal light before wavelength conversion; a nonlinear optical medium into which both the wavelength-multiplexed signal light and the excitation light emitted from the excitation light source can be simultaneously incident; and a wavelength separation unit that separates the light emitted from the nonlinear optical medium into optical components with wavelengths after wavelength conversion and optical components with wavelengths before wavelength conversion.

7. The optical wavelength conversion cross-connect device according to claim 1, characterized in that the wavelength conversion function unit converts wavelengths in the optical communication wavelength bands T-band (Thousand-band), O-band (Original-band), E-band (Extended-band), S-band (Short-wavelength-band), C-band (Conventional-band), L-band (Long-wavelength-band), or U-band (Ultralong-wavelength-band).

8. An optical network system comprising an optical wavelength conversion cross-connect device connected as an optical signal relay node to an optical fiber of a route that bundles together a plurality of optical fibers, wherein the optical wavelength conversion cross-connect device comprises: an optical cross-connect function unit that switches wavelength-multiplexed signal light, which is obtained by multiplexing optical signals of a plurality of wavelength bands input from an input route, for each route using a WSS (Wavelength Selective Switch) and outputs the signal light to an output route; and a wavelength conversion function unit that converts the wavelength of the wavelength-multiplexed signal light whose route is switched by the optical cross-connect function unit.

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