Wavelength band conversion device

Abstract

Provided is a wavelength band conversion device capable of, in a network for batch converting wavelength multiplex signals to transmit the same or for converting the wavelength multiplex signals into a receivable wavelength group, changing or setting a wavelength group for each wavelength multiplex signal at the time of transmission or changing or setting a path for transmitting / receiving the signals. A wavelength band conversion device (200) according to the present disclosure comprises: a first optical switch (202) for guiding an optical signal of an input wavelength group to an (N+1)-path group; a first wavelength band converter group (203a) for converting an optical signal of a wavelength group guided to an M-path group from among (N+1)-path groups from among the outputs of the first optical switch (202); a second wavelength band converter group (203b) for converting an optical signal of a wavelength group guided to an (N-M)-path group from among the outputs of the first optical switch (202); and second and third optical switches (204a and 204b) for controlling an output path of an optical signal of a wavelength group outputted from the first and second wavelength band converter groups (203a and 203b), wherein the optical signal of the wavelength group is not converted in a one-path group.

Description

Wavelength band conversion device

[0001] The present disclosure relates to a wavelength band conversion device.

[0002] With the spread of the Internet, the demand for data communication networks is rapidly increasing. To meet this rapidly increasing demand, optical communication networks that can transmit large amounts of data with low power consumption are being widely constructed.

[0003] Furthermore, optical transmission devices using optical switches can be used in optical communication networks, which enable flexible setting of paths between any number of points in the optical communication network.

[0004] In recent years, as an example of an optical transmission device that applies such an optical switch, a transmission device that uses multiple wavelength bands (e.g., C-band and L-band) for the purpose of transmitting more information through a single optical fiber has begun to be put into practical use (see, for example, non-patent document 1).

[0005] FIG. 1 is a diagram schematically illustrating the basic configuration of a conventional optical transmission device 100. Note that FIG. 1 illustrates, as an example, a case in which there is one input port for wavelength-multiplexed signals input from an external device and one output port for wavelength-multiplexed signals output to an external device. However, this is intended for illustrative purposes only, and the number of input ports and output ports (number of directions) of the optical transmission device 100 may be M (M is an integer equal to or greater than 1). Furthermore, in the optical transmission device 100 having such a configuration, as will be described later, the first optical switch is configured to output the direction of an optical signal of a wavelength group to one of M directions in accordance with a user selection. Note that in FIG. 1, the traveling direction of the optical signal is depicted by an arrow.

[0006] As shown in FIG. 1, optical transmission device 100 capable of connecting optical fibers with up to M directions includes a wavelength group demultiplexer 101 that demultiplexes an externally input wavelength-multiplexed signal into optical signals of N wavelength groups (N is an integer of 2 or more), N optical amplifiers 102a-c that amplify each of the optical signals of the N wavelength groups output from wavelength group demultiplexer 101, N 1-input M-output first optical switches 103a-c connected to the output ports of each of optical amplifiers 102a-c, N M-input 1-output second optical switches 104a-c connected to the output ports of each of first optical switches 103a-c, and a wavelength group multiplexer 105 connected to the output port of second optical switches 104a-c and multiplexing the input N wavelength groups. In addition, in Figure 1, the number N of optical signals of wavelength groups that are demultiplexed by the wavelength group demultiplexer 101 is depicted as 3, but this is intended as an example, and the number N can be set arbitrarily depending on the number of wavelength groups that the wavelength multiplexed signal has.

[0007] When a wavelength-multiplexed signal is input from outside the optical transmission device 100, the externally input wavelength-multiplexed signal is demultiplexed into N wavelength groups (three wavelength groups in the example of FIG. 1 ) by the wavelength group demultiplexer 101 (for example, demultiplexed into S-band, C-band, and L-band). Each of the demultiplexed optical signals of the N wavelength groups is input to a respective optical amplifier 102 a-c configured to be able to amplify the optical signal of that wavelength group. For example, the optical amplifier 102 a is configured to be able to amplify an optical signal of the S-band, the optical amplifier 102 b is configured to be able to amplify an optical signal of the C-band, and the optical amplifier 102 a is configured to be able to amplify an optical signal of the L-band.

[0008] The output ports of the optical amplifiers 102a-c are input to respective 1-input, M-output first optical switches 103a-c for selecting an output route. In the above example, an amplified S-band optical signal is input to the first optical switch 103a, an amplified C-band optical signal is input to the first optical switch 103b, and an amplified L-band optical signal is input to the first optical switch 103c. The optical signals of each wavelength group input to each of the first optical switches 103a-c are output to any of the M routes selected by the user and input to the corresponding second optical switches 104a-c. However, the output ports of each of the first optical switches 103a-c are all connected to respective input ports of different second optical switches 104a-c.

[0009] The second optical switches 104a-c are provided at each of the M output ports of the optical transmission device 100. As described above, the optical transmission device 100 is configured so that a user can select which of the M second optical switches 104a-c an optical signal of each wavelength group transmitted from each of the first optical switches 103a-c is input to. The output port of each of the second optical switches 104a-c is connected to an input port of a wavelength group multiplexer 105 provided at each of the M output ports. The wavelength group multiplexer 105 has the function of multiplexing and outputting optical signals of N wavelength groups.

[0010] The optical transmission device 100 having such a configuration has a function of routing wavelength-multiplexed signals bundled as wavelength groups as control units. Furthermore, the optical transmission device 100 can also be equipped with other functions, such as routing control functions on a wavelength-by-wavelength basis, a signal insertion / removal function, and a function for reducing the signal level deviation between wavelength-multiplexed signals. However, the optical transmission device 100 can be said to be the most basic node configuration when multiple wavelength bands are used.

[0011] In a basic node configuration that assumes the use of multiple wavelength bands, such as the optical transmission device 100, as described above, the unit of routing control is a coarse unit called a wavelength group. However, when wavelength groups are defined in relation to the corresponding bands of the optical amplifiers 102a-c, the only wavelength bands for which practical transmitters and receivers can be prepared are the C band (1530 nm to 1565 nm) and the L band (1565 nm to 1625 nm). Under such circumstances, when attempting to configure a node that uses multiple wavelength groups using wavelength bands other than the C band and the L band, it becomes necessary to generate signals other than the C band and the L band. One possible method for achieving this is to generate wavelength-multiplexed signals in the C band or the L band and then convert the wavelength-multiplexed signals all at once. Another possible method is to transmit optical signals in wavelength groups other than the C band and the L band, and then convert the transmitted wavelength-multiplexed signals all at once to wavelength-multiplexed signals in the C band or the L band as a means for receiving and generating signals.

[0012] However, in networks where such wavelength multiplexed signals are converted in bulk for transmission or converted into receivable wavelength groups, no functions have been proposed to date that improve convenience by making it possible to change or set the wavelength group used for transmission for each seed wavelength multiplexed signal, or to change or set the route for sending and receiving signals.

[0013] S. Yamamoto, H. Taniguchi, Y. Kisaka, S. Camatel, Y. Ma, D. Ogawa, K. Hadama, M. Fukutoku, T. Goh, and K. Suzuki: “First demonstration of a C+L band CDC-ROADM with a simple node configuration using multiband switching devices,” Optics Express, Vol. 29, No. 22, pp. 36353-36365, (2021)

[0014] The present disclosure has been made in consideration of the above-mentioned problems, and its purpose is to provide a wavelength band conversion device that enables changing or setting the wavelength group when transmitting each seed wavelength multiplexed signal, or enables changing or setting the route for sending and receiving signals, in a network in which wavelength multiplexed signals are converted in bulk and provided for transmission, or converted into a receivable wavelength group.

[0015] In response to the above-described problems, the present disclosure provides a wavelength band converter device, comprising: a first optical switch configured to guide an optical signal of an input wavelength group to an (N+1) degree group (N is an integer of 1 or more); a first wavelength band converter group that converts an optical signal of the wavelength group, which is output from the first optical switch and directed to M degree groups (M is an integer of 1 or more, provided that N>M) of the (N+1) degree group, into an optical signal of another wavelength group; and a second wavelength band converter group that converts an optical signal of the wavelength group, which is output from the first optical switch and directed to (N+1-M) degree groups different from the (N+1) degree group directed to the first wavelength band converter group. Provided is a wavelength band conversion device comprising: a second group of wavelength band converters that converts optical signals of the guided wavelength group into optical signals of another wavelength group; a second optical switch that controls the output route of the optical signals of the wavelength group output from each of the first group of wavelength band converters; and a third optical switch that controls the output route of the optical signals of the wavelength group output from each of the second group of wavelength band converters, wherein in one route group that is not guided to either the first group of wavelength band converters or the second group of wavelength band converters, the optical signals of the wavelength group are not converted into optical signals of the other wavelength group.

[0016] 1 is a diagram schematically illustrating a basic configuration of an optical transmission device 100 according to a conventional technique; FIG. 2 is a diagram conceptually illustrating a configuration of a wavelength band conversion device 200 according to a first embodiment of the present disclosure; and FIG. 3 is a diagram conceptually illustrating a configuration of a wavelength band conversion device 300 according to a second embodiment of the present disclosure.

[0017] Various embodiments of the present disclosure will be described in detail below with reference to the drawings. The same or similar reference numerals indicate the same or similar elements, and redundant description may be omitted. Materials and numerical values ​​are for illustrative purposes only and are not intended to limit the technical scope of the present disclosure. The following description is an example, and some configurations may be omitted or modified, or additional configurations may be added, as long as they do not deviate from the gist of one embodiment of the present disclosure.

[0018] 2 is a diagram conceptually illustrating the configuration of a wavelength band converter 200 according to a first embodiment of the present disclosure. As shown in FIG. 2, the wavelength band converter 200 includes a plurality of input terminals 201a-f, a first optical switch 202 configured to guide optical signals of wavelength groups input from the input terminals 201a-f to a first path group, a second path group, and a third path group according to a user's setting, first wavelength band converters 203a1-a3 that convert optical signals of wavelength groups guided to the first path group among the outputs of the first optical switch 202 into optical signals of another wavelength group, and a second wavelength band converter 203b1-b3 that converts an optical signal of the wavelength group guided to the first path group into an optical signal of another wavelength group; a second optical switch 204a that controls the output route of the optical signal of the wavelength group output from each of the first wavelength band converters 203a1-a3; and a third optical switch 204b that controls the output route of the optical signal of the wavelength group output from each of the second wavelength band converters 203b1-b3, and the third path group is configured so that the optical signal of the wavelength group is not converted into an optical signal of another wavelength group.

[0019] In the wavelength band converter 200, optical signals of wavelength groups received from the outside are input from input terminals 201a-f. The optical signals of the wavelength groups may be, for example, optical signals of wavelength groups that are routed from an optical transmission device (not shown) to which the wavelength band converter 200 is applied and guided to be input to the wavelength band converter 200. Note that, although FIG. 1 depicts a configuration in which there are six input terminals 201a-f, this is intended as an example, and the number of input terminals 201a-f may be set arbitrarily depending on the design.

[0020] The first optical switch 202 has a function of controlling the path of the optical signals of the wavelength group output from each of the input terminals 201a-f according to a user's selection (setting of the connection relationship between the input and output ports). In the example shown in FIG. 1, the first optical switch 202 is depicted as having 6 inputs and 10 outputs, so that the optical signals of the wavelength group output from each of the input terminals 201a-f can be output to either the first wavelength band converters 203a1-a3 (first path group), the second wavelength band converters 203b1-b3 (second path group), or the output terminals 205c1-c4 (third path group). However, the number of output ports and the number of path groups of the first optical switch 202 may be set to any number depending on the design. However, it is assumed that the third path group is one path group.

[0021] A portion of the output of the first optical switch 202 is connected to the first wavelength band converters 203a1-a3 and the second wavelength band converters 203b1-b3. The first wavelength band converters 203a1-a3 and the second wavelength band converters 203b1-b3 have the function of converting optical signals of the wavelength group guided by the first optical switch 202 into optical signals of different wavelength groups. The first wavelength band converters 203a1-a3 and the second wavelength band converters 203b1-b3 may be wavelength converters of different types. For example, if the first wavelength band converters 203a1-a3 are configured to convert optical signals of the C band into optical signals of the S band, the second wavelength band converters 203b1-b3 may be configured to convert optical signals of the C band into optical signals of the U band. The wavelength band converter 200 having such a configuration makes it possible to collectively convert wavelength-multiplexed signals into optical signals of different wavelength groups.

[0022] Each of the first wavelength band converters 203a1-a3 and the second wavelength band converters 203b1-b3 may be any known device that performs wavelength band conversion on an optical signal of an input wavelength group. For example, each of the first wavelength band converters 203a1-a3 and the second wavelength band converters 203b1-b3 may be a wavelength conversion element configured to perform wavelength conversion based on second-order nonlinear optical effects (sum frequency generation (SFG), difference frequency generation (DFG), second harmonic generation (SFG)) using periodically poled lithium niobate (PPLN). As another example, each of the first wavelength band converters 203a1-a3 and the second wavelength band converters 203b1-b3 may be a highly nonlinear fiber.

[0023] Each of the second optical switch 204a and the third optical switch 204b has a function of controlling the path of the optical signals of the converted wavelength bands output from each of the first wavelength band converters 203a1-a3 and the second wavelength band converters 203b1-b3. Here, as an example, each of the second optical switch 204a and the third optical switch 204b is illustrated as having a three-input / four-output configuration. In this example, each of the second optical switch 204a and the third optical switch 204b controls the optical signals of the converted wavelength bands output from each of the first wavelength band converters 203a1-a3 and the second wavelength band converters 203b1-b3 to be directed to one of the output terminals 205a1-a4, 205b1-b4, depending on the user's selection (setting of the connection relationship between the input and output ports).

[0024] Of the outputs of first optical switch 202, the outputs that are not connected to first wavelength band converters 203a1-a3 and second wavelength band converters 203b1-b3 are connected to output terminals 205c1-c4. Optical signals of the wavelength group guided to this path (third path) are output from output terminals 205c1-c4 without being converted into another wavelength group.

[0025] 2 illustrates an example in which there are 12 output terminals 205a1-a4, b1-b4, and c1-c4, but this is for illustrative purposes only and any number may be arranged depending on the design. Furthermore, it is desirable that the number of output terminals for each wavelength group match the number of input / output directions for long-distance transmission in the optical transmission device to which it is applied.

[0026] The wavelength band converter 200 according to the first embodiment of the present disclosure, having such a configuration, has the function of converting input optical signals of a wavelength group into an arbitrary wavelength group all at once and transmitting the signals toward a desired path. The wavelength band converter 200 having such a function makes it possible to change or set the wavelength group when transmitting each seed wavelength multiplexed signal, or to change or set the path for transmitting or receiving the signal.

[0027] 3 is a diagram conceptually illustrating a configuration of a wavelength band converter 300 according to a second embodiment of the present disclosure. As illustrated in FIG. 3, the wavelength band converter 300 includes a plurality of input terminals 301a1-a4, b1-b4, c1-c4, a first optical switch 302a that receives input from each of the input terminals 301a1-a4 and performs route control to guide optical signals of the wavelength group to a first path group, a second optical switch 302b that receives input from each of the input terminals 301b1-b4 and performs route control to guide optical signals of the wavelength group to a second path group, and a first optical switch 302c that converts the optical signals of the wavelength group output from the first optical switch 302a into optical signals of another wavelength group. The optical signal processing system includes wavelength band converters 303a1-a3, second wavelength band converters 303b1-b3 that convert optical signals of the wavelength group output from the second optical switch 302b into optical signals of another wavelength group, and a third optical switch 304 that controls the output route for each of the optical signals of the wavelength group output from the first wavelength band converters 303a1-a3, the optical signals of the wavelength group output from the second wavelength band converters 303b1-b3, and, as a third route group, the optical signals of the wavelength group that are input from input terminals 301c1-c4 and guided without being converted into another wavelength group.

[0028] The wavelength band converter 300 corresponds to a configuration in which the input and output of the wavelength band converter 200 shown in Fig. 2 are interchanged. In other words, if the wavelength band converter 200 is the outgoing path, the wavelength band converter 300 corresponds to the returning path.

[0029] The wavelength band converter 300 having such a configuration can also convert input wavelength multiplexed signals into appropriate wavelength groups in a batch and send them toward desired paths, similar to the wavelength band converter 200. The wavelength band converter 300 having such a function can convert the wavelength multiplexed signals into appropriate wavelength groups regardless of the wavelength group of the wavelength multiplexed signals to be transmitted or the path for transmitting and receiving the signals, and can receive the signals using a single type of device (i.e., a receiving device that is paired with a device that generates a seed wavelength multiplexed signal in the wavelength band converter 200).

[0030] As described above, the wavelength band conversion device according to the present disclosure makes it possible to change or set the wavelength group when transmitting each seed wavelength multiplexed signal, or to change or set the route for transmitting and receiving the signal. Therefore, it is expected to be applied to optical transmission devices capable of transmitting much larger amounts of data than conventional technologies.

Claims

1. A wavelength band converter comprising: a first optical switch configured to guide an input optical signal of a wavelength group to an (N+1) direction group (N is an integer of 1 or more); a first wavelength band converter group that converts optical signals of the wavelength group that are output from the first optical switch and directed to M direction group (M is an integer of 1 or more, where N≧M) of the (N+1) direction group into optical signals of another wavelength group; a second wavelength band converter group that converts optical signals of the wavelength group that are output from the first optical switch and directed to (N+1-M) direction group different from the (N+1) direction group that are directed to the first wavelength band converter group into optical signals of another wavelength group; a second optical switch that controls the output direction of the optical signals of the wavelength group output from each of the first wavelength band converter groups; and a third optical switch that controls the output direction of the optical signals of the wavelength group output from each of the second wavelength band converter groups, a wavelength band converter configured such that, in one direction group that is not guided to either the first wavelength band converter group or the second wavelength band converter group, optical signals of one wavelength group are not converted into optical signals of another wavelength group.

2. A wavelength band converter comprising: a first optical switch that controls the routing of optical signals of the wavelength group that are guided to a first path group among the optical signals of the input wavelength group; a second optical switch that controls the routing of optical signals of the wavelength group that are guided to a second path group different from the first path group among the optical signals of the input wavelength group; a first wavelength band converter group that converts the optical signals of the wavelength group that are output from the first optical switch into optical signals of another wavelength group; a second wavelength band converter group that converts the optical signals of the wavelength group that are output from the second optical switch into optical signals of another wavelength group; and a third optical switch that controls the output path for each of the optical signals of the wavelength group that are output from the first wavelength band converter group, the optical signals of the wavelength group that are output from the second wavelength band converter group, and the optical signals of the wavelength group that are input to a third path group different from the first and second path groups and guided thereto without being converted into another wavelength group.

3. A wavelength band conversion device according to claim 1 or 2, wherein the first group of wavelength band converters and the second group of wavelength band converters are either wavelength conversion elements configured to perform wavelength conversion based on the second-order nonlinear optical effect using periodically poled lithium niobate, or highly nonlinear fibers.

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