Wavelength selective switch, single board, equipment, system and method for transmitting optical signal

Abstract

The invention discloses a wavelength selective switch, a single board, equipment, a system and a method for transmitting optical signals, and belongs to the technical field of optical communication. The wavelength selection switch comprises a first output port, a plurality of first input ports, a first optical switching engine, a dispersion module and a second optical switching engine, the second optical switching engine comprises a first area and a second area, the first area comprises a plurality of first sub-areas, and the width of the second area is larger than or equal to 2.5 times of the size of a light spot. The first optical switching engine deflects a plurality of first single-wavelength optical signals input by the plurality of first input ports by a first angle. The dispersion module transmits first parts of the plurality of first single-wavelength optical signals to the plurality of first sub-regions and transmits second parts of the plurality of first single-wavelength optical signals to the second region, and the plurality of first parts are reflected back to the dispersion module on the plurality of first sub-regions; the dispersion module combines the plurality of first portions into a first multi-wavelength optical signal and transmits the first multi-wavelength optical signal to the first output port. The wavelength selection switch can avoid signal crosstalk.

Description

Technical Field

[0001] The present application relates to the field of optical communication technology, and in particular to a wavelength selective switch, a single board, a device, a system and a method for transmitting an optical signal. Background Art

[0002] With the development of optical communication technology, optical switching devices that use optical signals for communication are increasingly widely used. For example, the optical switching device may be a reconfigurable optical add drop multiplexer (ROADM).

[0003] A wavelength selective switch (WSS) is an important component of a ROADM. The WSS has a plurality of first input ports and a first output port corresponding to the plurality of first input ports. The WSS can transmit part of the first single-wavelength optical signal input from each first input port to the first output port, thereby achieving signal power attenuation.

[0004] The WSS further includes a plurality of second input ports. The WSS may also transmit part of the second single-wavelength optical signal input from each second input port to the first output port, resulting in crosstalk between the two signals at the first output port. Summary of the invention

[0005] The present application provides a wavelength selective switch, a single board, a device, a system and a method for transmitting optical signals, which can avoid signal crosstalk. The technical solution is as follows:

[0006] In a first aspect, the present application provides a wavelength selective switch, the wavelength selective switch comprising a first output port, a plurality of first input ports corresponding to the first output port, a first optical switching engine, a dispersion module, and a second optical switching engine, the second optical switching engine comprising a first region and a second region, the first region and the second region being adjacent, the first region comprising a plurality of first sub-regions corresponding to the first output port, the width of the second region being greater than or equal to 2.5 times the spot size. The plurality of first input ports are used to transmit a plurality of first single-wavelength optical signals to the first optical switching engine, each of the first single-wavelength optical signals comprising a first part and a second part. The first optical switching engine is used to deflect the plurality of first single-wavelength optical signals at a first angle and transmit them to the dispersion module. The dispersion module is used to transmit the first part of the plurality of first single-wavelength optical signals deflected at the first angle to the plurality of first sub-regions, transmit the second part of the plurality of first single-wavelength optical signals deflected at the first angle to the second region, the first part of the plurality of first single-wavelength optical signals deflected at the first angle is reflected back to the dispersion module on the plurality of first sub-regions, and the spot size is equal to the spot size of each first single-wavelength optical signal in the port direction. The dispersion module is further used to combine the first part of the multiple reflected first single-wavelength optical signals into a first multi-wavelength optical signal, and transmit the first multi-wavelength optical signal to the first output port.

[0007] Since the width of the second region is greater than or equal to 2.5 times the spot size, which is equal to the spot size of each first single-wavelength optical signal in the port direction, it is ensured that the dispersion module transmits the second part of the multiple first single-wavelength optical signals to the second region, and the second region does not reflect the second part of the multiple first single-wavelength optical signals. In this way, the dispersion module will not combine the second parts of the multiple first single-wavelength optical signals into a multi-wavelength optical signal, that is, it will not transmit the multi-wavelength optical signal to the output port of the wavelength selective switch except the first output port, thereby avoiding signal crosstalk.

[0008] In a possible implementation, the wavelength selective switch further includes: a second output port and a plurality of second input ports corresponding to the second output port, the second optical switching engine further includes a third area, the third area is adjacent to the second area, the second area is located between the first area and the third area, and the third area includes a plurality of second sub-areas corresponding to the second output port. The plurality of second input ports are used to transmit a plurality of second single-wavelength optical signals to the first optical switching engine, each of which includes a third part and a fourth part. The first optical switching engine is further used to transmit the plurality of second single-wavelength optical signals to the dispersion module after deflecting the second angle, wherein the first angle and the second angle are different. The dispersion module is used to transmit the third part of the plurality of second single-wavelength optical signals deflected by the second angle to the plurality of second sub-areas, transmit the fourth part of the plurality of second single-wavelength optical signals deflected by the second angle to the second area, and reflect the third part of the plurality of second single-wavelength optical signals deflected by the second angle back to the dispersion module on the plurality of second sub-areas. The dispersion module is further used to merge the third part of the plurality of second single-wavelength optical signals after reflection into a second multi-wavelength optical signal, and transmit the second multi-wavelength optical signal to the second output port. In this way, the first output port and the second output port share the second area, thereby improving the space utilization of the second optical switching engine and reducing the size of the second optical switching engine.

[0009] In another possible implementation, the wavelength selective switch further includes a third optical switching engine, a third output port, and a plurality of third input ports corresponding to the third output port, the first output port and the plurality of first input ports belong to a first port group, the third output port and the plurality of third input ports belong to a second port group, the first port group and the second port group are arranged relatively, and the second area includes a plurality of third sub-areas corresponding to the third output port. The plurality of third input ports are used to transmit a plurality of third single-wavelength optical signals to the third optical switching engine, each of the third single-wavelength optical signals includes a fifth part and a sixth part. The third optical switching engine is used to transmit the plurality of third single-wavelength optical signals to the dispersion module after deflecting the third angle, and the first angle and the third angle are different. The dispersion module is used to transmit the fifth part of the plurality of third single-wavelength optical signals deflected at the third angle to the plurality of third sub-areas, and to transmit the sixth part of at least one third single-wavelength optical signal to at least one first sub-area, wherein the plurality of first sub-areas include the at least one first sub-area, the plurality of third single-wavelength optical signals deflected at the third angle include the at least one third single-wavelength optical signal, the fifth part of the plurality of third single-wavelength optical signals deflected at the third angle is reflected back to the dispersion module on the plurality of third sub-areas, and the sixth part of the at least one third single-wavelength optical signal is reflected back to the dispersion module on the at least one first sub-area. The dispersion module is also used to combine the fifth part of the plurality of third single-wavelength optical signals after reflection into a third multi-wavelength optical signal, and transmit the third multi-wavelength optical signal to the third output port, and to combine the sixth part of the at least one third single-wavelength optical signal after reflection into a fourth multi-wavelength optical signal, and transmit the fourth multi-wavelength optical signal to a direction other than the port included in the wavelength selection switch. Since the second area includes the plurality of third sub-areas corresponding to the third output port, the space utilization rate of the second optical switching engine is improved.

[0010] In another possible implementation, the first offset in the dispersion direction between the center of the i-th first sub-region and the center of the i-th third sub-region is greater than or equal to 0 and less than or equal to the sum of the widths of 20 first sub-regions, i = 1, 2, 3, ..., K, where K is the number of the multiple first sub-regions.

[0011] In another possible implementation, the wavelength selective switch further includes a beam combiner and a deflection unit. The first optical switching engine is used to transmit the multiple first single-wavelength optical signals deflected by the first angle to the beam combiner. The third optical switching engine is used to transmit the multiple third single-wavelength optical signals deflected by the third angle to the deflection unit. The deflection unit is used to deflect the multiple third single-wavelength optical signals transmitted by the third optical switching engine to the beam combiner. The beam combiner is used to transmit the multiple first single-wavelength optical signals transmitted by the first optical switching engine and the multiple third single-wavelength optical signals deflected by the deflection unit to the dispersion module. In this way, the second offset between the i-th first single-wavelength optical signal and the i-th third single-wavelength optical signal in the dispersion direction can be reduced by the beam combiner, thereby reducing the first offset between the center of the i-th first sub-region and the center of the i-th third sub-region in the dispersion direction, so as to reduce the width of the second optical switching engine.

[0012] In another possible implementation, the second offset in the dispersion direction between the i-th first single-wavelength optical signal and the i-th third single-wavelength optical signal transmitted by the combiner to the dispersion module is constrained by the first offset, and the first offset is the offset in the dispersion direction between the center of the i-th first sub-region and the center of the i-th third sub-region, i=1, 2, 3, ..., K, where K is the number of the multiple first sub-regions.

[0013] In another possible implementation, the wavelength selective switch further includes: a lens; a beam combiner, which is used to transmit the multiple first single-wavelength optical signals transmitted by the first optical switching engine and the multiple third single-wavelength optical signals deflected by the deflection unit to the lens. The lens is used to transmit the multiple first single-wavelength optical signals and the multiple third single-wavelength optical signals transmitted by the beam combiner to the dispersion module. Since the beam combiner is located between the lens and the first optical switching engine, the first multi-wavelength optical signal and the third multi-wavelength optical signal transmitted by the beam combiner share the lens, so there is no need to set a lens between the deflection unit and the dispersion module, thereby reducing the cost of the wavelength selective switch.

[0014] In a second aspect, the present application provides a method for transmitting an optical signal, the method being applied to a wavelength selective switch, the wavelength selective switch comprising: a first output port, a plurality of first input ports corresponding to the first output port, a first optical switching engine, a dispersion module, and a second optical switching engine, the second optical switching engine comprising a first region and a second region, the first region and the second region being adjacent, the first region comprising a plurality of first sub-regions corresponding to the first output port, and the width of the second region being greater than or equal to 2.5 times the spot size. In the method, the plurality of first input ports transmit a plurality of first single-wavelength optical signals to the first optical switching engine, each of the first single-wavelength optical signals comprising a first part and a second part. The first optical switching engine deflects the plurality of first single-wavelength optical signals at a first angle and transmits them to the dispersion module. The dispersion module transmits the first part of the plurality of first single-wavelength optical signals deflected at the first angle to the plurality of first sub-regions, transmits the second part of the plurality of first single-wavelength optical signals deflected at the first angle to the second region, and the first part of the plurality of first single-wavelength optical signals deflected at the first angle is reflected back to the dispersion module on the plurality of first sub-regions, and the spot size is equal to the spot size of each first single-wavelength optical signal in the port direction. The dispersion module combines the first part of the reflected multiple first single-wavelength optical signals into a first multi-wavelength optical signal, and transmits the first multi-wavelength optical signal to the first output port.

[0015] Since the width of the second region is greater than or equal to 2.5 times the spot size, which is equal to the spot size of each first single-wavelength optical signal in the port direction, it is ensured that the dispersion module transmits the second part of the multiple first single-wavelength optical signals to the second region, and the second region does not reflect the second part of the multiple first single-wavelength optical signals. In this way, the dispersion module will not combine the second parts of the multiple first single-wavelength optical signals into a multi-wavelength optical signal, that is, the multi-wavelength optical signal will not be transmitted to the output port of the wavelength selective switch other than the first output port, thereby avoiding signal crosstalk.

[0016] In a possible implementation, the wavelength selective switch further includes: a second output port and a plurality of second input ports corresponding to the second output port, the second optical switching engine further includes a third area, the third area is adjacent to the second area, the second area is located between the first area and the third area, and the third area includes a plurality of second sub-areas corresponding to the second output port. The plurality of second input ports transmit a plurality of second single-wavelength optical signals to the first optical switching engine, each of which includes a third part and a fourth part. The first optical switching engine deflects the plurality of second single-wavelength optical signals at a second angle and transmits them to the dispersion module, wherein the first angle and the second angle are different. The dispersion module transmits the third part of the plurality of second single-wavelength optical signals deflected at the second angle to the plurality of second sub-areas, transmits the fourth part of the plurality of second single-wavelength optical signals deflected at the second angle to the second area, and the third part of the plurality of second single-wavelength optical signals deflected at the second angle is reflected back to the dispersion module on the plurality of second sub-areas. The dispersion module combines the third part of the plurality of second single-wavelength optical signals after reflection into a second multi-wavelength optical signal, and transmits the second multi-wavelength optical signal to the second output port. In this way, the first input port and the second input port share the second area, thereby improving the space utilization of the second optical switching engine and reducing the size of the second optical switching engine.

[0017] In another possible implementation, the wavelength selective switch further includes a third optical switching engine, a third output port, and a plurality of third input ports corresponding to the third output port, the first output port and the plurality of first input ports belong to a first port group, the third output port and the plurality of third input ports belong to a second port group, the first port group and the second port group are arranged relatively, and the second area includes a plurality of third sub-areas corresponding to the third output port. The plurality of third input ports transmit a plurality of third single-wavelength optical signals to the third optical switching engine, and each third single-wavelength optical signal includes a fifth part and a sixth part. The third optical switching engine deflects the plurality of third single-wavelength optical signals by a third angle and transmits them to the dispersion module, and the first angle and the third angle are different. The dispersion module transmits the fifth part of the plurality of third single-wavelength optical signals deflected at the third angle to the plurality of third sub-areas, and transmits the sixth part of at least one third single-wavelength optical signal to at least one first sub-area, the plurality of first sub-areas include at least one first sub-area, the plurality of third single-wavelength optical signals deflected at the third angle include the at least one third single-wavelength optical signal, the fifth part of the plurality of third single-wavelength optical signals deflected at the third angle is reflected back to the dispersion module on the plurality of third sub-areas, and the sixth part of the at least one third single-wavelength optical signal is reflected back to the dispersion module on the at least one first sub-area. The dispersion module combines the fifth part of the plurality of third single-wavelength optical signals after reflection into a third multi-wavelength optical signal, and transmits the third multi-wavelength optical signal to the third output port, and combines the sixth part of the at least one third single-wavelength optical signal after reflection into a fourth multi-wavelength optical signal, and transmits the fourth multi-wavelength optical signal to a direction other than the port included in the wavelength selective switch. Since the second area includes the plurality of third sub-areas corresponding to the third input port, the space utilization of the second optical switching engine is improved.

[0018] In a third aspect, the present application provides a single board, comprising: at least one wavelength selective switch described in the first aspect or any possible implementation of the first aspect.

[0019] In a fourth aspect, the present application provides an optical switching device, comprising a plurality of boards, at least one of the plurality of boards being the board described in the third aspect.

[0020] In a possible implementation manner, the optical switching device is a reconfigurable optical branching multiplexer.

[0021] In a fifth aspect, the present application provides an optical network system, comprising: a plurality of optical switching devices, at least one optical switching device among the plurality of optical switching devices is the optical switching device described in the fourth aspect or any possible implementation of the fourth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1It is a structural schematic diagram of an optical switching device provided in an embodiment of the present application;

[0023] Figure 2 is a light path diagram of a wavelength selective switch provided in an embodiment of the present application;

[0024] Figure 3 is another optical path diagram of a wavelength selective switch provided in an embodiment of the present application;

[0025] Figure 4 It is a structural schematic diagram of an optical switching engine provided in an embodiment of the present application;

[0026] Figure 5 It is a partial structural schematic diagram of a wavelength selective switch provided in an embodiment of the present application;

[0027] Figure 6 It is a partial structural schematic diagram of a wavelength selective switch provided in an embodiment of the present application;

[0028] Figure 7 It is a partial structural schematic diagram of another wavelength selective switch provided in an embodiment of the present application;

[0029] Figure 8 It is a partial structural schematic diagram of another wavelength selective switch provided in an embodiment of the present application;

[0030] Fig. 9 It is a partial structural schematic diagram of another wavelength selective switch provided in an embodiment of the present application;

[0031] Fig.10 It is a partial structural schematic diagram of another wavelength selective switch provided in an embodiment of the present application;

[0032] Fig.11 It is a partial structural schematic diagram of another wavelength selective switch provided in an embodiment of the present application;

[0033] Fig.12 It is a partial structural schematic diagram of another wavelength selective switch provided in an embodiment of the present application;

[0034] Fig.13 It is a partial structural schematic diagram of another wavelength selective switch provided in an embodiment of the present application;

[0035] Fig.14 It is a partial structural schematic diagram of another wavelength selective switch provided in an embodiment of the present application;

[0036] Fig.15 It is a partial structural schematic diagram of another wavelength selective switch provided in an embodiment of the present application;

[0037] Fig.16It is a partial structural schematic diagram of another wavelength selective switch provided in an embodiment of the present application;

[0038] Fig.17 is a schematic diagram of the structure of a wavelength selective switch provided in an embodiment of the present application;

[0039] Fig.18 It is a flow chart of a method for transmitting optical signals provided in an embodiment of the present application. DETAILED DESCRIPTION

[0040] The implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0041] The present application provides an optical network system, which includes a plurality of optical switching devices, wherein optical signals can be exchanged between the optical switching devices through optical fibers.

[0042] In some embodiments, the optical switching device may be a device such as ROADM that can switch optical signals. Among them, ROADM can realize flexible scheduling and intelligent operation and maintenance of all-optical network services, and has wavelength-level scheduling and multi-dimensional flexible networking capabilities. After introducing ROADM into the optical network system, operators can quickly provide wavelength-level services, facilitate network planning, reduce operating expenses, facilitate maintenance, and reduce maintenance costs.

[0043] For example, Figure 1 A schematic diagram of the structure of a ROADM provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, ROADM includes multiple boards, some of which are located in Figure 1 The other part of the board is located on the line side of Figure 1 The client side of the ROADM. A board on the client side connects the transmitter (transmitter, TX) and the receiver (receiver, RX). The board can also realize optical switching. ROADM uses multiple boards to exchange light to realize ROADM optical switching.

[0044] The board includes at least one wavelength selective switch (WSS), Figure 1In the example, a single board includes multiple wavelength selective switches. Some wavelength selective switches have 1 input port and N output ports (expressed as 1×N, N>1), or some wavelength selective switches have M input ports and N output ports (expressed as M×N, M>1, N>1). The wavelength selective switch can combine single-wavelength optical signals from multiple input ports (also called wavelength division ports) into multi-wavelength optical signals (such as wavelength division multiplexing (WDM) signals), and transmit the multi-wavelength optical signals to one output port (also called a wavelength combination port). In addition to at least one wavelength selective switch, a single board may also include other components, which are not listed here.

[0045] ROADM can transmit an optical signal of any wavelength at any input port of the ROADM to any output port of the ROADM by connecting the ports of multiple wavelength selective switches.

[0046] In some embodiments, the optical switching device may also be a device different from the ROADM, the number of boards in the device (>1) is different from the number of boards in the ROADM, and / or the connection relationship between the boards in the device is different from the connection relationship between the boards in the ROADM. Therefore, the optical switching device provided in the present application may include multiple boards, and there is a connection relationship between these boards. Through the connection between the boards, optical switching of the optical switching device can be achieved. In addition to multiple boards, the optical switching device may also include other components. For example, the optical switching device also includes a power module, a heat dissipation module, etc. The power module is used to supply power to the board, and the heat dissipation module is used to dissipate heat from the board.

[0047] Based on the above, it can be seen that the wavelength selective switch is an important component of the single board, optical switching equipment and optical switching system. Figure 2 The structure of the wavelength selective switch is further introduced.

[0048] For example, Figure 2 (a) or Figure 3 (a) is a light path diagram of a wavelength selective switch provided in an embodiment of the present application in the port direction x, which is the orthographic projection of the transmission path of the optical signal between the ports of the wavelength selective switch on the reference plane xz, that is, Figure 2 (a) and Figure 3(a) is the optical path diagram shown. Among them, the orthographic projections of the multiple ports of the wavelength selective switch in the reference plane xz can be arranged in sequence along the port direction x. The arrangement direction of the multiple ports can be the port direction x, or can be different from the port direction x, which is not limited in the present application. The orthographic projection of the transmission path on the reference plane xz refers to: when light perpendicular to the reference plane xz is irradiated from the side of the transmission path away from the reference plane xz to the reference plane xz, the projection of the transmission path on the reference plane xz.

[0049] The reference plane xz is perpendicular to the dispersion direction y. For example, Figure 2 (b) and Figure 3 (b) is an optical path diagram of the wavelength selective switch provided in the embodiment of the present application in the dispersion direction y. For a plurality of first single-wavelength optical signals input from a plurality of first input ports (such as I1, I2 and I3 in the figure) included in the wavelength selective switch, in the dispersion direction y, the projection of the transmission path of the plurality of first single-wavelength optical signals on the reference plane yz is as follows: Figure 2 (b) as shown.

[0050] Among them, see Figure 2 (a) and (b), the multiple first input ports (such as I1, I2 and I3 in the figure) input multiple first single-wavelength optical signals to the first optical switching engine. The first optical switching engine deflects the multiple first single-wavelength optical signals by a first angle and transmits them to the dispersion module. The dispersion module transmits the multiple first single-wavelength optical signals to multiple positions (such as Figure 2 (b) and Figure 3 (b) at the positions L1, L2, L3), the plurality of first single-wavelength optical signals are reflected back to the dispersion module at the plurality of positions.

[0051] See also Figure 3 (a) and (b), the multiple first input ports (such as I1, I2 and I3 in the figure) of the wavelength selective switch correspond to a first output port (such as O1 in the figure). The dispersion module combines the multiple first single-wavelength optical signals into a multi-wavelength optical signal and transmits the multi-wavelength optical signal to the first output port.

[0052] The wavelength selective switch can realize the attenuation function of signal power.

[0053] In order to realize the attenuation function of signal power, the wavelength selective switch includes multiple output ports. Assuming that the multiple output ports include a first output port O1 and a second output port O2, the wavelength selective switch includes multiple first input ports (such as I1, I2 and I3 in the figure) corresponding to the first output port O1 and multiple second input ports (not shown in the figure) corresponding to the second output port O2. Figure 4The second optical switching engine includes a row of sub-areas corresponding to the first output port O1 and a row of sub-areas corresponding to the second output port O2, and the row of sub-areas corresponding to the first output port O1 and the row of sub-areas corresponding to the second output port O2 are adjacent. The row of sub-areas corresponding to the first output port O1 includes a plurality of first sub-areas, and the row of sub-areas corresponding to the second output port O2 includes a plurality of second sub-areas.

[0054] See also Figure 2 , a plurality of first input ports (I1, I2 and I3) input a plurality of first single-wavelength optical signals to the first optical switching engine, each of the first single-wavelength optical signals including a first part and a second part. The first optical switching engine deflects the plurality of first single-wavelength optical signals by a first angle and transmits them to the dispersion module. The dispersion module transmits the first part of the plurality of first single-wavelength optical signals deflected by the first angle to a plurality of first sub-areas of the second optical switching engine, and transmits the second part of the plurality of first single-wavelength optical signals deflected by the first angle to a plurality of second sub-areas of the first optical switching engine.

[0055] See also Figure 3 , the first part of the multiple first single-wavelength optical signals after being deflected at the first angle is reflected back to the dispersion module on the multiple first sub-areas, and the second part of the multiple first single-wavelength optical signals after being deflected at the first angle is reflected back to the dispersion module on the multiple second sub-areas. The dispersion module combines the first part of the multiple first single-wavelength optical signals after being reflected into a multi-wavelength optical signal, and transmits the multi-wavelength optical signal to the first output port O1, thereby realizing the attenuation function of the signal power.

[0056] The dispersion module combines the second part of the reflected multiple first single-wavelength optical signals into another multi-wavelength optical signal, and transmits the other multi-wavelength optical signal to the second output port O2. This will cause the other multi-wavelength optical signal to generate signal crosstalk with the multi-wavelength optical signal on the second output port O2. Therefore, when the wavelength selective switch realizes the attenuation function of the signal power, the problem of signal crosstalk will also occur.

[0057] To solve the above problems, see Figure 5 and Figure 6 , the embodiment of the present application provides a wavelength selection switch 500, the wavelength selection switch 500 comprising:

[0058] the first output port O1a, the first output port O1a corresponding to the plurality of first input ports (such as Figure 5I1a, I2a and I3a shown), a first optical switching engine 2, a dispersion module 3 and a second optical switching engine 4. The second optical switching engine 4 includes a first area 41 and a second area 42, the first area 41 and the second area 42 are adjacent, the first area 41 includes a plurality of first sub-areas 411 corresponding to the first output port O1a, and the width of the second area is greater than or equal to 2.5 times the spot size.

[0059] See also Figure 5 , multiple first input ports (such as Figure 5 I1a, I2a, I3a) shown are used to transmit a plurality of first single-wavelength optical signals to the first optical switching engine 2, each of the first single-wavelength optical signals comprising a first part and a second part;

[0060] The first optical switching engine 2 is used for deflecting the plurality of first single-wavelength optical signals by a first angle and then transmitting them to the dispersion module 3;

[0061] The dispersion module 3 is used to transmit the first part of the plurality of first single-wavelength optical signals after being deflected at the first angle to the plurality of first sub-areas 411, and transmit the second part of the plurality of first single-wavelength optical signals after being deflected at the first angle to the second area 42; wherein, see Figure 6 , a first part of the plurality of first single-wavelength optical signals after being deflected at the first angle is reflected back to the dispersion module 3 on the plurality of first sub-regions 411 , and the spot size is equal to the spot size of each first single-wavelength optical signal in the port direction;

[0062] The dispersion module 3 is further used to combine the first part of the multiple first single-wavelength optical signals after reflection into a first multi-wavelength optical signal, and output it to the first output port (such as Figure 6 The shown O1a) transmits a first multi-wavelength optical signal.

[0063] In some embodiments, the plurality of first single-wavelength optical signals are signals received by the plurality of first input ports.

[0064] In some embodiments, the first angle is constrained by the positions of the plurality of first sub-regions 411 and the position of the second region 42 .

[0065] For the first part of the plurality of first single-wavelength optical signals transmitted to the plurality of first sub-areas 411, the plurality of first sub-areas 411 may reflect the first part of the plurality of first single-wavelength optical signals toward the dispersion module 3. For the second part of the plurality of first single-wavelength optical signals transmitted to the second area 42, the second area 42 may not reflect the second part of the plurality of first single-wavelength optical signals.

[0066] Since the multiple first sub-regions 411 reflect the first parts of the multiple first single-wavelength optical signals back to the dispersion module 3, the dispersion module 3 combines the first parts of the multiple first single-wavelength optical signals into a first multi-wavelength optical signal, so that the power of the first multi-wavelength optical signal is less than the sum of the powers of the multiple first single-wavelength optical signals, and the first multi-wavelength optical signal is transmitted to the first output port, thereby realizing the attenuation function of the signal power.

[0067] Since the width of the second region 42 is greater than or equal to 2.5 times the size of the light spot, the dispersion module 3 can make the second parts of the multiple first single-wavelength optical signals fall in the second region 42, and the second region 42 does not reflect the second parts of the multiple first single-wavelength optical signals to the dispersion module 3. In this way, for other output ports of the wavelength selective switch 500 except the first output port O1a, the dispersion module 3 will not transmit the multi-wavelength optical signal combined by the second parts of the multiple first single-wavelength optical signals to other output ports, thereby not generating crosstalk with the multi-wavelength optical signals on other output ports.

[0068] For each first sub-region 411 in the first region 41 , the dispersion module 3 may transmit a first portion of a first single-wavelength optical signal to the first sub-region 411 , and the first sub-region 411 reflects the first portion of the first single-wavelength optical signal back to the dispersion module 3 .

[0069] In some embodiments, each of the plurality of first single-wavelength optical signals has a different wavelength.

[0070] See also Figure 5 or Figure 6 , the first output port O1a corresponds to the first area 41 and the second area 42 in the second optical switching engine 4. Similarly, the wavelength selective switch 500 may also include other output ports, and the second optical switching engine 4 also includes two areas corresponding to the other output ports, wherein the structure of one area is the same as that of the first area 41, and the structure of the other area is the same as that of the second area 42.

[0071] For example, see Figure 5 or Figure 6 The wavelength selective switch 500 further includes a second output port O2a and a plurality of second input ports (eg, Figure 5 The second optical switching engine 4 further includes a third area 43 and a fourth area 44 corresponding to the second output port O2a, the third area 43 includes a plurality of second sub-areas 431 corresponding to the second output port O2a, and the width of the fourth area 44 is greater than or equal to 2.5 of the spot size.

[0072] The plurality of second input ports (I4a, I5a) are used to transmit a plurality of second single-wavelength optical signals (not shown) to the first optical switching engine 2, each of the second single-wavelength optical signals comprising a third part and a fourth part;

[0073] The first optical switching engine 2 is further used for transmitting the plurality of second single-wavelength optical signals to the dispersion module 3 after deflecting the plurality of second single-wavelength optical signals at a fifth angle, wherein the first angle and the fifth angle are different;

[0074] The dispersion module 3 is further configured to transmit the third part of the plurality of second single-wavelength optical signals after being deflected at a fifth angle to the plurality of second sub-regions 431, transmit the fourth part of the plurality of second single-wavelength optical signals after being deflected at the fifth angle to the fourth region 44, and reflect the third part of the plurality of second single-wavelength optical signals after being deflected at the fifth angle back to the dispersion module 3 on the plurality of second sub-regions 431;

[0075] The dispersion module 3 is further used to combine the third part of the reflected multiple second single-wavelength optical signals into a second multi-wavelength optical signal, and output it to the second output port (such as Figure 6 O2a) shown transmits a second multi-wavelength optical signal.

[0076] In some embodiments, the fifth angle is constrained by the positions of the plurality of second sub-regions 431 and the position of the fourth region 44 .

[0077] In some embodiments, each of the plurality of second single-wavelength optical signals has a different wavelength.

[0078] for Figure 5 and Figure 6 In the wavelength selective switch 500 of the structure shown, each output port in the wavelength selective switch 500 corresponds to two areas, such as the first output port O1a corresponds to the first area 41 and the second area 42, and the second output port O2a corresponds to the third area 43 and the fourth area 44, which will increase the size of the second optical switching engine 4.

[0079] In order to reduce the size of the second optical switching engine 4, the first output port O1a and the second output port O2a may share the second area 42. Figure 7 and Figure 8 The third area 43 and the second area 42 included in the second optical switching engine 4 are adjacent to each other, the second area 42 is located between the first area 41 and the third area 43, and the third area 43 includes a plurality of second sub-areas 431 corresponding to the second output port O2a.

[0080] See also Figure 7 , the plurality of second input ports (such as Figure 7I4a, I5a) shown, used to transmit a plurality of second single-wavelength optical signals to the first optical switching engine 2, each second single-wavelength optical signal comprising a third part and a fourth part;

[0081] The first optical switching engine 2 is further used for transmitting the plurality of second single-wavelength optical signals to the dispersion module 3 after deflecting the signals by a second angle;

[0082] The dispersion module 3 is further used to transmit the third part of the plurality of second single-wavelength optical signals after being deflected at the second angle to the plurality of second sub-areas 431, and to transmit the fourth part of the plurality of second single-wavelength optical signals after being deflected at the second angle to the second area 42; wherein, see Figure 8 , a third part of the plurality of second single-wavelength optical signals is reflected back to the dispersion module 3 on the plurality of second sub-areas 431;

[0083] The dispersion module 3 is further used to combine the third part of the reflected multiple second single-wavelength optical signals into a second multi-wavelength optical signal, and output it to the second output port (such as Figure 8 O2a) shown transmits a second multi-wavelength optical signal.

[0084] Since the first output port O1a and the second output port O2a share the second area 42 , the number of second areas 42 included in the second optical switching engine 4 can be reduced, thereby improving the space utilization of the second optical switching engine 4 and reducing the size of the second optical switching engine 4 .

[0085] In some embodiments, the second angle is constrained by the positions of the plurality of second sub-regions 431 and the position of the second region 42 .

[0086] For the third part of the plurality of second single-wavelength optical signals transmitted to the plurality of second sub-regions 431, the plurality of second sub-regions 431 may reflect the third part of the plurality of second single-wavelength optical signals toward the dispersion module 3. For the fourth part of the plurality of second single-wavelength optical signals transmitted to the second region 42, the second region may not reflect the fourth part of the plurality of second single-wavelength optical signals.

[0087] Since the multiple second sub-regions 431 reflect the third parts of the multiple second single-wavelength optical signals back to the dispersion module 3, the dispersion module 3 combines the third parts of the multiple second single-wavelength optical signals into a second multi-wavelength optical signal, so that the power of the second multi-wavelength optical signal is less than the sum of the powers of the multiple second single-wavelength optical signals, and the second multi-wavelength optical signal is transmitted to the second output port, thereby realizing the attenuation function of the signal power.

[0088] Since the width of the second region is greater than or equal to 2.5 times the size of the light spot, the dispersion module 3 can make the fourth parts of the multiple second single-wavelength optical signals fall into the second region, and the second region does not reflect the fourth parts of the multiple second single-wavelength optical signals to the dispersion module 3. In this way, for other output ports included in the wavelength selective switch 500 except the second output port, the dispersion module 3 will not transmit the fourth parts of the multiple second single-wavelength optical signals to other output ports, thereby not generating crosstalk with the multi-wavelength optical signals on other output ports.

[0089] See also Figure 7 or Figure 8 , the first output port O1a and the second output port O2a correspond to the first area 41, the second area 42 and the third area 43 in the second optical switching engine 4. Similarly, the wavelength selective switch 500 may also include two other adjacent output ports, and the second optical switching engine 4 also includes three areas corresponding to the other two adjacent output ports, and the structures of the three areas are the same as the structures of the first area 41, the second area 42 and the third area 43. In this way, the two adjacent output ports share the second area 42, thereby reducing the size of the second optical switching engine 4.

[0090] In some embodiments, see Figures 5 to 8 The wavelength selective switch 500 further includes a first lens 51, a second lens 52 and a separation component 53. The first lens 51 and the second lens 52 form a 4f optical path.

[0091] See also Figure 5 and Figure 7 , the plurality of first input ports (such as Figure 5 or Figure 7 I1a, I2a, I3a) shown are used to transmit a plurality of first single-wavelength optical signals to the first optical switching engine 2;

[0092] The first optical switching engine 2 is used for deflecting the plurality of first single-wavelength optical signals by a first angle and then transmitting them to the separation component 53;

[0093] A separation component 53, used for deflecting the plurality of first single-wavelength optical signals after being deflected at a first angle to the second lens 52;

[0094] The second lens 52 is used to transmit the plurality of first single-wavelength optical signals deflected by the separation component 53 to the dispersion module 3 .

[0095] a dispersion module 3, configured to transmit a first portion of the plurality of first single-wavelength optical signals transmitted through the second lens 52 to the plurality of first sub-regions 411, and transmit a second portion of the plurality of first single-wavelength optical signals transmitted through the second lens 52 to the second region 42, wherein the first portion of the plurality of first single-wavelength optical signals transmitted through the second lens 52 is reflected back to the dispersion module 3 on the plurality of first sub-regions 411;

[0096] See also Figure 6 or Figure 8 , the dispersion module 3 is also used to combine the first part of the multiple first single-wavelength optical signals reflected by the multiple first sub-regions 411 into a first multi-wavelength optical signal, and transmit the first multi-wavelength optical signal to the second lens 52;

[0097] The second lens 52 is also used to transmit the first multi-wavelength optical signal to the first lens 51;

[0098] The first lens 51 is used to transmit the first multi-wavelength optical signal transmitted by the second lens 52 to the first output port (such as Figure 6 or Figure 8 O1a shown).

[0099] For the above Figures 5 to 8 In the wavelength selective switch 500 shown, the space utilization rate of the first optical switching engine 4 is not high because the second area 42 in the wavelength selective switch 500 does not reflect the optical signal. Therefore, the wavelength selective switch 500 can be designed as a twin structure, that is, the wavelength selective switch 500 can be a twin wavelength selective switch.

[0100] See also Fig. 9 and Fig.10 The twin structure wavelength selection switch 500 comprises a first port group and a second port group which are arranged opposite to each other. The first port group comprises the first output port O1a and a plurality of first input ports (such as Fig. 9 I1a, I2a, I3a), the second port group includes a third output port O1b and a plurality of third input ports (such as Fig. 9 As shown in FIGS. 11a, 11b, 12b, and 13b, the second area 42 includes a plurality of third sub-areas 421 corresponding to the third output port O1b; the wavelength selective switch 500 also includes a third optical switching engine 3.

[0101] See also Fig. 9 , the plurality of third input ports (such as Fig. 9 I1b, I2b, I3b) shown, used to transmit a plurality of third single-wavelength optical signals to the third optical switching engine 3, each third single-wavelength optical signal comprising a fifth part and a sixth part;

[0102] The third optical switching engine 3 is used for deflecting the plurality of third single-wavelength optical signals by a third angle and then transmitting them to the dispersion module 3;

[0103] The dispersion module 3 is further used to transmit the fifth part of the plurality of third single-wavelength optical signals deflected by the third angle to the plurality of third sub-areas 421, and transmit the sixth part of at least one third single-wavelength optical signal to at least one first sub-area 411, wherein the plurality of first sub-areas 411 include the at least one first sub-area 411, and the plurality of third single-wavelength optical signals deflected by the third angle include the at least one third single-wavelength optical signal; wherein, see Fig.10 , the fifth part of the plurality of third single-wavelength optical signals is reflected back to the dispersion module 3 on the plurality of third sub-regions 421, and the sixth part of the at least one third single-wavelength optical signal is reflected back to the dispersion module 3 on the at least one first sub-region 411;

[0104] The dispersion module 3 is further used to combine the fifth part of the plurality of third single-wavelength optical signals after reflection into a third multi-wavelength optical signal, and output the third multi-wavelength optical signal to the third output port (such as Fig.10 The third multi-wavelength optical signal is transmitted as shown in (b), and the sixth part of the at least one third single-wavelength optical signal is combined into a fourth multi-wavelength optical signal after reflection, and the fourth multi-wavelength optical signal is transmitted in a direction other than the port included in the wavelength selective switch 500.

[0105] For the multiple first single-wavelength optical signals transmitted by the first optical switching engine 2 to the dispersion module 3, the dispersion module 3 transmits the second part of at least one first single-wavelength optical signal among the multiple first single-wavelength optical signals to at least one third sub-region 421, and the multiple third sub-regions 421 include the at least one third sub-region 421; the second part of the at least one first single-wavelength optical signal is reflected back to the dispersion module 3 on the at least one third sub-region 421. The dispersion module 3 combines the reflected second part of the at least one first single-wavelength optical signal into a fifth multi-wavelength optical signal, and transmits the fifth multi-wavelength optical signal to a direction other than the port included in the wavelength selective switch 500.

[0106] Since the plurality of first input ports (such as Fig. 9 I1a, I2a, I3a) and the plurality of third input ports (such as Fig. 9As shown, I1b, I2b, and I3b) belong to different port groups, and the wavelength of each first single-wavelength optical signal transmitted by the plurality of first input ports is different from the wavelength of each third single-wavelength optical signal transmitted by the plurality of third input ports. Thus, for each first sub-region 411 in the at least one first sub-region 411, the optical signal transmitted to the first sub-region 411 includes a first part of a first single-wavelength optical signal and a sixth part of a third single-wavelength optical signal. Since the wavelength of the first part of the first single-wavelength optical signal is different from the wavelength of the sixth part of the third single-wavelength optical signal, the dispersion module 3 combines the first parts of the multiple first single-wavelength optical signals reflected by the multiple first sub-regions 411 into a first multi-wavelength optical signal, and the dispersion module 3 combines the sixth part of the at least one third single-wavelength optical signal reflected by the at least one first sub-region 411 into a fourth multi-wavelength optical signal, so that the dispersion module 3 transmits the first multi-wavelength optical signal in a different direction from the fourth multi-wavelength optical signal, that is, the dispersion module 3 transmits the first multi-wavelength optical signal to the first output port O1a, and transmits the fourth multi-wavelength optical signal to a direction other than the port included in the wavelength selective switch 500.

[0107] Similarly, for each third sub-region 421 in the at least one third sub-region 421, the optical signal transmitted to the third sub-region 421 includes the second part of a first single-wavelength optical signal and the fifth part of a third single-wavelength optical signal. Since the wavelength of the second part of the first single-wavelength optical signal is different from the wavelength of the fifth part of the third single-wavelength optical signal, the dispersion module 3 combines the second parts of the plurality of first single-wavelength optical signals reflected by the plurality of third sub-regions 421 to form a fifth multi-wavelength optical signal, and the dispersion module 3 combines the fifth parts of the plurality of third single-wavelength optical signals reflected by the plurality of third sub-regions 421 to form a third multi-wavelength optical signal. The transmission direction of the third multi-wavelength optical signal and the transmission direction of the fifth multi-wavelength optical signal are different, that is, the dispersion module 3 transmits the third multi-wavelength optical signal to the third output port O1b, and transmits the combined fifth multi-wavelength optical signal to a direction other than the port included in the wavelength selective switch 500. In this way, the attenuation of signal power is achieved and signal crosstalk is avoided.

[0108] In some embodiments, the third angle is constrained by the position of the at least one first sub-region 411 and the positions of the plurality of third sub-regions 421 .

[0109] In some embodiments, the first optical switching engine 2 and the third optical switching engine 6 may be integrated together, or may be two different components.

[0110] In some embodiments, each of the plurality of third single-wavelength optical signals has a different wavelength.

[0111] In some embodiments, the first port group includes a column of input ports and a column of output ports, the column of input ports includes the above-mentioned multiple first input ports and multiple second input ports, the column of output ports includes the above-mentioned first output port and second output port, and the column of input ports and the column of output ports may be located in different columns or in the same column.

[0112] In some embodiments, the second port group includes a column of input ports and a column of output ports, the column of input ports includes the above-mentioned multiple third input ports, the column of output ports includes the above-mentioned third output ports, and the column of input ports and the column of output ports may be located in different columns or in the same column.

[0113] In some embodiments, the first offset between the center of the i-th first sub-region and the center of the i-th third sub-region in the dispersion direction is constrained by the spacing between the first port group and the second port group, i=1, 2, 3, ..., K, K is the number of the plurality of first sub-regions 411. The first offset between the center of the i-th first sub-region and the center of the i-th third sub-region in the dispersion direction is in direct proportion to the spacing between the first port group and the second port group.

[0114] In some embodiments, see Fig.11 and Fig.12 The second output port O2a and the plurality of second input ports (such as Fig.11 The third area 43 of the second optical switching engine 4 includes a plurality of second sub-areas 431 corresponding to the second output port O2a. The plurality of second sub-areas 431 in the third area 43 are sub-areas corresponding to the second output port O2a in the first port group.

[0115] Therefore, for any two adjacent rows of sub-areas in the second optical switching engine 4, one row of sub-areas is a plurality of sub-areas corresponding to one output port in the first port group, and the other row of sub-areas is a plurality of sub-areas corresponding to one output port in the second port group. Fig.11 or Fig.12 In the second optical switching engine 4, a row of first sub-areas 411 in the first area 41 are multiple sub-areas corresponding to the first output port O1a in the first port group, a row of third sub-areas 421 in the second area 42 are multiple sub-areas corresponding to the first output port O1b in the second port group, and a row of second sub-areas 431 in the third area 43 are multiple sub-areas corresponding to the second output port O2a in the first port group.

[0116] The dispersion module 3 may not transmit the sixth part of the third single-wavelength optical signal to the second area 42, but transmit the sixth part of the third single-wavelength optical signal to the third area 43. That is, for the first single-wavelength optical signal, the dispersion module 3 transmits the first part of the first single-wavelength optical signal to the first sub-area 411 in the first area 41, and transmits the second part of the first single-wavelength optical signal to the third sub-area 421 in the second area 42. For the third single-wavelength optical signal, the dispersion module 3 transmits the fifth part of the third single-wavelength optical signal to the third sub-area 421 in the second area 42, and transmits the sixth part of the third single-wavelength optical signal to the second sub-area 431 in the third area 43. When implemented,

[0117] See also Fig.11 , the plurality of third input ports (such as Fig.11 I1b, I2b, I3b) shown, used for the third optical switching engine 6 to transmit multiple third single-wavelength optical signals, each of which includes a fifth part and a sixth part;

[0118] The third optical switching engine 6 is used for transmitting the plurality of third single-wavelength optical signals to the dispersion module 3 after deflecting the signals at a fourth angle, wherein the first angle and the fourth angle are different;

[0119] The dispersion module 3 is further used to transmit the fifth part of the plurality of third single-wavelength optical signals deflected by the fourth angle to the plurality of third sub-areas 421, and transmit the sixth part of at least one third single-wavelength optical signal to at least one second sub-area 431, wherein the plurality of second sub-areas 431 include the at least one second sub-area 431, and the plurality of third single-wavelength optical signals deflected by the fourth angle include the at least one third single-wavelength optical signal; wherein, see Fig.12 , the fifth part of the plurality of third single-wavelength optical signals is reflected back to the dispersion module 3 on the plurality of third sub-regions 421 , and the sixth part of the at least one third single-wavelength optical signal is reflected back to the dispersion module 3 on the at least one second sub-region 431 ;

[0120] The dispersion module 3 is further configured to combine a fifth portion of the plurality of third single-wavelength optical signals reflected by the plurality of third sub-regions 421 into a third multi-wavelength optical signal, and transmit the third multi-wavelength optical signal to the third output port, and combine a sixth portion of the at least one third single-wavelength optical signal reflected by the at least one second sub-region 431 into a fourth multi-wavelength optical signal, and transmit the fourth multi-wavelength optical signal to a direction other than the port included in the wavelength selective switch 500.

[0121] In some embodiments, the fourth angle is constrained by the positions of the plurality of third sub-regions 421 and the position of the at least one second sub-region 431 .

[0122] As for the multiple first single-wavelength optical signals deflected by the first angle transmitted by the first optical switching engine 2 to the dispersion module 3, the dispersion module 3 still transmits the first part of the multiple first single-wavelength optical signals deflected by the first angle to the multiple first sub-areas 411, and transmits the second part of at least one first single-wavelength optical signal deflected by the first angle to at least one third sub-area 421; wherein the first part of the multiple first single-wavelength optical signals deflected by the first angle is reflected back to the dispersion module 3 on the multiple first sub-areas 411, and the second part of at least one first single-wavelength optical signal deflected by the first angle is reflected back to the dispersion module 3 on the at least one second sub-area 421.

[0123] Then, the dispersion module 3 combines the first parts of the multiple first single-wavelength optical signals reflected by the multiple first sub-areas 411 into a first multi-wavelength optical signal, and transmits the first multi-wavelength optical signal to the first output port, and combines the second part of the at least one first single-wavelength optical signal reflected by the at least one third sub-area 421 into a fifth multi-wavelength optical signal, and transmits the fifth multi-wavelength optical signal to a direction other than the port included in the wavelength selective switch 500.

[0124] In the second optical switching engine 4, a row of sub-regions (including multiple sub-regions) corresponding to other output ports in the first port group and a row of sub-regions (including multiple sub-regions) corresponding to other output ports in the second port group are arranged alternately, like a row of first sub-regions 411 corresponding to the first output port and a row of third sub-regions 421 corresponding to the third output port.

[0125] In some embodiments, in addition to corresponding to multiple first input ports, the first output port O1a may also correspond to at least one fourth input port. The wavelength selection switch 500 may not attenuate the first single-wavelength optical signal input to the at least one fourth input port, and the first area 41 of the second optical switching engine 4 also includes at least one first sub-area 411.

[0126] That is, the at least one fourth input port is used to transmit at least one first single-wavelength optical signal to the first optical switching engine 2;

[0127] The first optical switching engine 2 is further used for transmitting the at least one first single-wavelength optical signal to the dispersion module 3 after deflecting the at least one first single-wavelength optical signal by a fifth angle, where the fifth angle is different from the first angle;

[0128] The dispersion module 3 is further used to transmit the at least one first single-wavelength optical signal after being deflected at a fifth angle to the at least one first sub-region 411; wherein the at least one first single-wavelength optical signal after being deflected at the fifth angle is reflected back to the dispersion module 3 on the at least one first sub-region 411;

[0129] The dispersion module 3 is further configured to combine the at least one first single-wavelength optical signal that has been reflected into a sixth multi-wavelength optical signal, and transmit the sixth multi-wavelength optical signal to the first output port.

[0130] In some embodiments, the fifth angle is constrained by the position of the at least one first sub-region 411 .

[0131] In some embodiments, see Fig.13 , the wavelength selective switch 500 further includes a beam combiner 55 and a deflection unit 56;

[0132] The first optical switching engine 2 is used for transmitting the plurality of first single-wavelength optical signals deflected by the first angle to the beam combiner 55 after deflecting the plurality of first single-wavelength optical signals by the first angle;

[0133] The third optical switching engine 6 is used for transmitting the third single-wavelength optical signals deflected at the third angle or the fourth angle to the deflection unit 56 after deflecting the plurality of third single-wavelength optical signals at the third angle or the fourth angle;

[0134] A deflection unit 56, used for deflecting the plurality of third single-wavelength optical signals transmitted by the third optical switching engine 6 to the beam combiner 55;

[0135] The beam combiner 55 is used to transmit the multiple first single-wavelength optical signals transmitted by the first optical switching engine 2 and the multiple third single-wavelength optical signals deflected by the deflection unit 56 to the dispersion module 3 .

[0136] In this way, the second offset between the i-th first single-wavelength optical signal and the i-th third single-wavelength optical signal transmitted to the dispersion module 3 in the dispersion direction can be reduced, and the second offset is directly proportional to the first offset between the center of the i-th first sub-region and the center of the i-th third sub-region in the dispersion direction, i=1, 2, 3, ..., K. Therefore, the smaller the second offset, the smaller the first offset, so that the width of the second optical switching engine 4 can be reduced.

[0137] Optionally, the second offset may be 0 or slightly greater than 0, so that the first offset may also be 0 or slightly greater than 0.

[0138] In some embodiments, the beam combiner 55 and the deflection unit 56 may be integrated together, or may be two different components.

[0139] In some embodiments, see Fig.13 The wavelength selection switch 500 further includes: a third lens 57 and a fourth lens 58 ; the beam combiner 55 is located between the second lens 52 and the dispersion module 3 , and the deflection unit 56 is located between the fourth lens 58 and the dispersion module 3 .

[0140] See also Fig.13 , a first optical switching engine 2, configured to transmit the plurality of first single-wavelength optical signals deflected by the first angle to the separation component 53 after deflecting the plurality of first single-wavelength optical signals by the first angle;

[0141] The third optical switching engine 6 is used for transmitting the plurality of third single-wavelength optical signals deflected by the third angle or the fourth angle to the separation component 53 after the plurality of third single-wavelength optical signals are deflected by the third angle or the fourth angle;

[0142] A separation component 53, used for transmitting the plurality of first single-wavelength optical signals transmitted by the first optical switching engine 2 to the second lens 52, and transmitting the plurality of third single-wavelength optical signals transmitted by the third optical switching engine 6 to the fourth lens 58;

[0143] The second lens 52 is used to transmit the plurality of first single-wavelength optical signals transmitted by the separation component 53 to the beam combiner 55;

[0144] The fourth lens 58 is used to transmit the plurality of third single-wavelength optical signals transmitted by the separation component 53 to the deflection sound 5655;

[0145] a deflection unit 56, configured to deflect the plurality of third single-wavelength optical signals transmitted through the fourth lens 58 to the beam combiner 55;

[0146] The beam combiner 55 is used to transmit the multiple first single-wavelength optical signals transmitted through the second lens 52 and the multiple third single-wavelength optical signals transmitted through the fourth lens 58 to the dispersion module 3 .

[0147] See also Fig.14 , a dispersion module 3, configured to transmit the first multi-wavelength optical signal and the third multi-wavelength optical signal to the combiner 55 after merging to obtain the first multi-wavelength optical signal and merging to obtain the third multi-wavelength optical signal;

[0148] The beam combiner 55 is further used to transmit the first multi-wavelength optical signal to the second lens 52, and transmit the third multi-wavelength optical signal to the deflection unit 56;

[0149] The first lens 51 and the second lens 52 form a 4f optical path. The second lens 52 is also used to transmit the first multi-wavelength optical signal transmitted through the combiner 55 to the first lens 51. Then, the first lens 51 is used to transmit the first multi-wavelength optical signal transmitted through the second lens 52 to the first output port O1a.

[0150] The third lens 57 and the fourth lens 58 form another 4f optical path. The deflection unit 56 is also used to deflect the third multi-wavelength optical signal transmitted through the combiner 55 to the fourth lens 58; the fourth lens 58 is also used to transmit the third multi-wavelength optical signal deflected by the deflection unit 56 to the third lens 57; then, the third lens 57 is used to transmit the third multi-wavelength optical signal transmitted through the fourth lens 58 to the third output port O1b.

[0151] In some embodiments, see Fig.14 and Fig.15 , the beam combiner 55 can be located between the first lens 51 and the second lens 52, so that the fourth lens 58 can be omitted to save costs.

[0152] See also Fig.15 , a first optical switching engine 2, configured to transmit the plurality of first single-wavelength optical signals deflected by the first angle to the separation component 53 after deflecting the plurality of first single-wavelength optical signals by the first angle;

[0153] The third optical switching engine 6 is used for transmitting the plurality of third single-wavelength optical signals deflected by the third angle or the fourth angle to the separation component 53 after the plurality of third single-wavelength optical signals are deflected by the third angle or the fourth angle;

[0154] A separation component 53, used for transmitting the plurality of first single-wavelength optical signals transmitted by the first optical switching engine 2 to the second lens 52, and transmitting the plurality of third single-wavelength optical signals transmitted by the third optical switching engine 6 to the fourth lens 58;

[0155] The second lens 52 is used to transmit the plurality of first single-wavelength optical signals transmitted by the separation component 53 to the beam combiner 55;

[0156] The fourth lens 58 is used to transmit the plurality of third single-wavelength optical signals transmitted by the separation component 53 to the deflection sound 5655;

[0157] a deflection unit 56, configured to deflect the plurality of third single-wavelength optical signals transmitted through the fourth lens 58 to the beam combiner 55;

[0158] The beam combiner 55 is used to transmit the multiple first single-wavelength optical signals transmitted through the second lens 52 and the multiple third single-wavelength optical signals transmitted through the fourth lens 58 to the dispersion module 3 .

[0159] See also Fig.16 , a dispersion module 3, configured to transmit the first multi-wavelength optical signal and the third multi-wavelength optical signal to the second lens 52 after merging to obtain the first multi-wavelength optical signal and merging to obtain the third multi-wavelength optical signal;

[0160] The second lens 52 is also used to transmit the first multi-wavelength optical signal and the third multi-wavelength optical signal to the beam combiner 55;

[0161] The beam combiner 55 is further used to transmit the first multi-wavelength optical signal transmitted through the second lens 52 to the first lens 51, and to transmit the third multi-wavelength optical signal transmitted through the second lens 52 to the deflection unit 56;

[0162] The first lens 51 is used to transmit the first multi-wavelength optical signal transmitted through the beam combiner 55 to the first output port O1a.

[0163] The deflection unit 56 is further used to deflect the third multi-wavelength optical signal transmitted through the beam combiner 55 to the third lens 57;

[0164] The third lens 57 is used to transmit the third multi-wavelength optical signal transmitted through the beam combiner 55 to the third output port O1b.

[0165] In some embodiments, see Figures 9 to 16 , the first offset of the center of the i-th first sub-region 411 and the center of the i-th third sub-region 421 in the dispersion direction is greater than or equal to 0 and less than or equal to the sum of the widths of 10 first sub-regions 411, i=1, 2, 3,...

[0166] For example, see Figures 9 to 12 , a first offset between the center of the i-th first sub-region 411 and the center of the i-th third sub-region 421 in the dispersion direction is equal to the width of one first sub-region 411 .

[0167] Assuming that the number of the multiple first single-wavelength optical signals received by the dispersion module 3 is Q, Q is an integer greater than or equal to 3, the number of the multiple first sub-regions 411 and the number of the multiple third sub-regions 421 are both Q, the dispersion module 3 transmits the first part of the Q first single-wavelength optical signals to the Q first sub-regions 411, and transmits the second part of the Q-2 first single-wavelength optical signals to the Q-2 third sub-regions 421, and the Q-2 third sub-regions 421 are the 2nd to Q-1th third sub-regions 421.

[0168] For example, see Figures 13 to 16 , a first offset between the center of the i-th first sub-region 411 and the center of the i-th third sub-region 421 in the dispersion direction is greater than or equal to 0 and less than half of the width of one first sub-region 411. When the dispersion module 3 receives the plurality of first single-wavelength optical signals, the dispersion module 3 transmits a first portion of the plurality of first single-wavelength optical signals to the plurality of first sub-regions 411, and transmits a second portion of the plurality of first single-wavelength optical signals to the plurality of third sub-regions 421.

[0169] The dispersion module 3 may be a transmission-type dispersion module 3 or a reflection-type dispersion module 3 .

[0170] In some embodiments, the dispersion module 3 is a transmission dispersion module 3, see Figures 5 to 16 The dispersion module 3 includes a transmissive dispersion grating 31 , a fifth lens 32 and a sixth lens 33 , and the dispersion grating 31 is located between the fifth lens 32 and the sixth lens 33 .

[0171] The fifth lens 32 is located between the dispersion grating 31 and the second lens 52 , and the sixth lens 33 is located between the dispersion grating 31 and the first optical switching engine 4 .

[0172] The fifth lens 32 and the sixth lens 33 form a 4f optical path. The first optical switching engine 2 transmits the multiple first single-wavelength optical signals after being deflected at the first angle to the front focal plane of the fifth lens 32. The fifth lens 33 transmits the multiple first single-wavelength optical signals to the dispersion grating 31, and the dispersion grating 31 transmits the first part of the multiple first single-wavelength optical signals to the sixth lens 33, and transmits the second part of the multiple first single-wavelength optical signals to the sixth lens 33. The sixth lens 33 transmits the first part of the multiple first single-wavelength optical signals transmitted through the dispersion grating 31 to the multiple first sub-regions 411; and transmits the second part of the multiple first single-wavelength optical signals transmitted through the dispersion grating 31 to the second region 42.

[0173] The first part of the multiple first single-wavelength optical signals is reflected back to the sixth lens 33 on the multiple first sub-regions 411, and the sixth lens 33 transmits the reflected first part of the multiple first single-wavelength optical signals to the dispersion grating 31. The dispersion grating 31 combines the first part of the multiple first single-wavelength optical signals transmitted through the sixth lens 33 into a first multi-wavelength optical signal, and transmits the first multi-wavelength optical signal to the fifth lens 32. The fifth lens 32 transmits the first multi-wavelength optical signal to the second lens 52. The second lens 52 transmits the first multi-wavelength optical signal transmitted through the fifth lens 32 to the first lens 51. The first lens 51 then transmits the first multi-wavelength optical signal transmitted through the second lens to the first output port O1a.

[0174] In some embodiments, the dispersion module 3 is a reflective dispersion module 3, see Fig.17 The dispersion module 3 includes a reflective dispersion grating 31 and a curved mirror 34 .

[0175] See also Fig.17 (a), a plurality of first input ports (such as Fig.17 (a) I1a, I2a, I3a), used to transmit a plurality of first single-wavelength optical signals to the first optical switching engine 2;

[0176] The first optical switching engine 2 is used for deflecting the plurality of first single-wavelength optical signals by a first angle and then transmitting them to the separation component 53;

[0177] A separation component 53, used for transmitting the plurality of first single-wavelength optical signals after being deflected at the first angle to the second lens 52;

[0178] The second lens 52 is used to transmit the plurality of first single-wavelength optical signals transmitted by the separation component 53 to the curved mirror 34;

[0179] A curved mirror 34, used for reflecting the plurality of first single-wavelength optical signals to the dispersion grating 31;

[0180] The dispersion grating 31 is used to reflect the multiple first single-wavelength optical signals back to the curved mirror 34;

[0181] The curved mirror 34 is also used to transmit the first part of the plurality of first single-wavelength optical signals to the plurality of first sub-areas 411 included in the second optical switching engine 4; and transmit the second part of the plurality of first single-wavelength optical signals to the second area 42 included in the second optical switching engine 4; see Fig.17 (b) The first part of the multiple first single-wavelength optical signals is reflected back to the curved mirror 34 on the multiple first sub-regions 411 .

[0182] See also Fig.17 (b), the curved mirror 34 is further used to reflect the first part of the reflected multiple first single-wavelength optical signals to the dispersion grating 31;

[0183] The dispersion grating 31 is further used to combine the first part of the multiple first single-wavelength optical signals reflected by the curved mirror 34 into a first multi-wavelength optical signal, and transmit the first multi-wavelength optical signal to the curved mirror 34;

[0184] The curved mirror 34 is also used to transmit the first multi-wavelength optical signal to the second lens 52;

[0185] The second lens 52 is also used to transmit the first multi-wavelength optical signal reflected by the curved mirror 34 to the first lens 51;

[0186] The first lens 51 is used to transmit the first multi-wavelength optical signal transmitted through the second lens 52 to the first output port O1a.

[0187] In an embodiment of the present application, the second optical switching engine includes a first area and a second area, the first area and the second area are adjacent, the first area includes a plurality of first sub-areas corresponding to the first output port, and the width of the second area is greater than or equal to 2.5 times the spot size. The plurality of first input ports are used to transmit a plurality of first single-wavelength optical signals to the first optical switching engine, each of which includes a first part and a second part. The first optical switching engine is used to deflect the plurality of first single-wavelength optical signals by a first angle and transmit them to the dispersion module. The dispersion module is used to transmit the first part of the plurality of first single-wavelength optical signals deflected by the first angle to the plurality of first sub-areas, transmit the second part of the plurality of first single-wavelength optical signals deflected by the first angle to the second area, and the first part of the plurality of first single-wavelength optical signals deflected by the first angle is reflected back to the dispersion module on the plurality of first sub-areas, and the spot size is equal to the spot size of each first single-wavelength optical signal in the port direction. The dispersion module is also used to merge the first part of the plurality of first single-wavelength optical signals reflected into a first multi-wavelength optical signal, and transmit the first multi-wavelength optical signal to the first output port. Since the width of the second region is greater than or equal to 2.5 times the spot size, which is equal to the spot size of each first single-wavelength optical signal in the port direction, it is ensured that the dispersion module transmits the second part of the multiple first single-wavelength optical signals to the second region, and the second region does not reflect the second part of the multiple first single-wavelength optical signals. In this way, the dispersion module will not combine the second parts of the multiple first single-wavelength optical signals into a multi-wavelength optical signal, that is, the multi-wavelength optical signal will not be transmitted to the output port of the wavelength selective switch other than the first output port, thereby avoiding signal crosstalk.

[0188] See also Fig.18 The embodiment of the present application provides a method 600 for transmitting an optical signal, wherein the method 600 is applied to a wavelength selective switch, wherein the wavelength selective switch may be Figures 5 to 17 The wavelength selective switch 500 in any embodiment includes: a first output port, a plurality of first input ports corresponding to the first output port, a first optical switching engine, a dispersion module, and a second optical switching engine, wherein the second optical switching engine includes a first area and a second area, the first area and the second area are adjacent, the first area includes a plurality of first sub-areas corresponding to the first output port, and the width of the second area is greater than or equal to 2.5 times the spot size. The method 600 includes:

[0189] Step 601: The plurality of first input ports transmit a plurality of first single-wavelength optical signals to a first optical switching engine, each of the first single-wavelength optical signals comprising a first part and a second part.

[0190] Step 602: The first optical switching engine deflects the plurality of first single-wavelength optical signals by a first angle and transmits the deflected signals to a dispersion module.

[0191] Step 603: The dispersion module transmits the first part of the multiple first single-wavelength optical signals after being deflected at the first angle to the multiple first sub-areas, and transmits the second part of the multiple first single-wavelength optical signals after being deflected at the first angle to the second area. The first part of the multiple first single-wavelength optical signals after being deflected at the first angle is reflected back to the dispersion module on the multiple first sub-areas, and the spot size is equal to the spot size of each first single-wavelength optical signal in the port direction.

[0192] Step 604: The dispersion module combines the reflected first part of the plurality of first single-wavelength optical signals into a first multi-wavelength optical signal, and transmits the first multi-wavelength optical signal to the first output port.

[0193] In some embodiments, the wavelength selective switch further includes: a second output port and a plurality of second input ports corresponding to the second output port, the second optical switching engine further includes a third area, the third area is adjacent to the second area, the second area is located between the first area and the third area, and the third area includes a plurality of second sub-areas corresponding to the second output port. The method 600 further includes the following processes 11 to 14.

[0194] 11: The plurality of second input ports transmit a plurality of second single-wavelength optical signals to the first optical switching engine, each of the second single-wavelength optical signals including a third part and a fourth part.

[0195] 12: The first optical switching engine deflects the plurality of second single-wavelength optical signals at a second angle and transmits the deflected signals to the dispersion module, wherein the first angle and the second angle are different.

[0196] 13: The dispersion module transmits the multiple second single-wavelength optical signals after being deflected at the second angle to the multiple second sub-areas, transmits the fourth part of the multiple second single-wavelength optical signals after being deflected at the second angle to the second area, and the third part of the multiple second single-wavelength optical signals after being deflected at the second angle is reflected back to the dispersion module at the multiple second sub-areas.

[0197] 14: The dispersion module combines the reflected third parts of the plurality of second single-wavelength optical signals into a second multi-wavelength optical signal, and transmits the second multi-wavelength optical signal to the second output port.

[0198] In some embodiments, the wavelength selective switch further includes a third optical switching engine, a third output port, and a plurality of third input ports corresponding to the third output port, the first output port and the plurality of first input ports belong to a first port group, the third output port and the plurality of third input ports belong to a second port group, the first port group and the second port group are arranged relative to each other, and the second area includes a plurality of third sub-areas corresponding to the third output port. The method 600 further includes the following processes 21 to 24.

[0199] 21: The plurality of third input ports transmit a plurality of third single-wavelength optical signals to the third optical switching engine, each of the third single-wavelength optical signals including a fifth portion and a sixth portion.

[0200] 22: The third optical switching engine deflects the plurality of third single-wavelength optical signals by a third angle and transmits the deflected signals to the dispersion module, wherein the first angle and the third angle are different.

[0201] 23: The dispersion module transmits the fifth part of the multiple third single-wavelength optical signals after being deflected by the third angle to the multiple third sub-regions, and transmits the sixth part of at least one third single-wavelength optical signal to at least one first sub-region, the multiple first sub-regions include the at least one first sub-region, the multiple third single-wavelength optical signals after being deflected by the third angle include the at least one third single-wavelength optical signal, the fifth part of the multiple third single-wavelength optical signals after being deflected by the third angle is reflected back to the dispersion module on the multiple third sub-regions, and the sixth part of the at least one third single-wavelength optical signal is reflected back to the dispersion module on the at least one first sub-region.

[0202] 24: The dispersion module combines the fifth part of the reflected multiple third single-wavelength optical signals into a third multi-wavelength optical signal, and transmits the third multi-wavelength optical signal to the third output port, and combines the sixth part of at least one third single-wavelength optical signal that has been reflected into a fourth multi-wavelength optical signal, and transmits the fourth multi-wavelength optical signal to a direction other than the port included in the wavelength selective switch.

[0203] In an embodiment of the present application, the second optical switching engine includes a first area and a second area, the first area and the second area are adjacent, the first area includes a plurality of first sub-areas corresponding to the first output port, and the width of the second area is greater than or equal to 2.5 times the spot size. The dispersion module transmits the first part of the received plurality of first single-wavelength optical signals to the plurality of first sub-areas, transmits the second part of the plurality of first single-wavelength optical signals to the second area, and the first part of the plurality of first single-wavelength optical signals is reflected back to the dispersion module on the plurality of first sub-areas. The dispersion module combines the first part of the reflected plurality of first single-wavelength optical signals into a first multi-wavelength optical signal, and transmits the first multi-wavelength optical signal to the first output port. Since the width of the second area is greater than or equal to 2.5 times the spot size, the spot size is equal to the spot size of each first single-wavelength optical signal in the port direction, so that the dispersion module is ensured to transmit the second part of the plurality of first single-wavelength optical signals to the second area, and the second area will not reflect the second part of the plurality of first single-wavelength optical signals, thereby avoiding signal crosstalk.

[0204] A person skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware or by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a disk or an optical disk, etc.

[0205] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present application shall be included in the protection scope of the present application.

Claims

1. A wavelength selective switch, characterized in that: The wavelength selective switch comprises: a first output port, a plurality of first input ports corresponding to the first output port, a first optical switching engine, a dispersion module, and a second optical switching engine, wherein the second optical switching engine comprises a first area and a second area, the first area and the second area are adjacent, the first area comprises a plurality of first sub-areas corresponding to the first output port, and a width of the second area is greater than or equal to 2.5 times of a light spot size; The plurality of first input ports are used to transmit a plurality of first single-wavelength optical signals to the first optical switching engine, each of the first single-wavelength optical signals comprising a first part and a second part; The first optical switching engine is used to deflect the plurality of first single-wavelength optical signals by a first angle and transmit them to the dispersion module; The dispersion module is used to transmit the first part of the plurality of first single-wavelength optical signals after being deflected at a first angle to the plurality of first sub-areas, and transmit the second part of the plurality of first single-wavelength optical signals after being deflected at the first angle to the second area, and the first part of the plurality of first single-wavelength optical signals after being deflected at the first angle is reflected back to the dispersion module on the plurality of first sub-areas, and the spot size is equal to the spot size of each first single-wavelength optical signal in the port direction; The dispersion module is further configured to combine a first portion of the reflected first single-wavelength optical signals into a first multi-wavelength optical signal, and transmit the first multi-wavelength optical signal to the first output port.

2. The wavelength selective switch according to claim 1, characterized in that: The wavelength selective switch further includes: a second output port and a plurality of second input ports corresponding to the second output port, the second optical switching engine further includes a third area, the third area is adjacent to the second area, the second area is located between the first area and the third area, and the third area includes a plurality of second sub-areas corresponding to the second output port; The plurality of second input ports are used to transmit a plurality of second single-wavelength optical signals to the first optical switching engine, each second single-wavelength optical signal comprising a third part and a fourth part; The first optical switching engine is further used to transmit the plurality of second single-wavelength optical signals to the dispersion module after deflecting them at a second angle, wherein the first angle and the second angle are different; The dispersion module is used to transmit the third part of the plurality of second single-wavelength optical signals after being deflected at the second angle to the plurality of second sub-areas, transmit the fourth part of the plurality of second single-wavelength optical signals after being deflected at the second angle to the second area, and reflect the third part of the plurality of second single-wavelength optical signals after being deflected at the second angle back to the dispersion module on the plurality of second sub-areas; The dispersion module is further configured to combine the reflected third portion of the plurality of second single-wavelength optical signals into a second multi-wavelength optical signal, and transmit the second multi-wavelength optical signal to the second output port.

3. The wavelength selective switch according to claim 1, characterized in that: The wavelength selective switch further includes a third optical switching engine, a third output port, and a plurality of third input ports corresponding to the third output port, the first output port and the plurality of first input ports belong to a first port group, the third output port and the plurality of third input ports belong to a second port group, the first port group and the second port group are arranged opposite to each other, and the second area includes a plurality of third sub-areas corresponding to the third output port; The plurality of third input ports are used to transmit a plurality of third single-wavelength optical signals to the third optical switching engine, each of the third single-wavelength optical signals comprising a fifth portion and a sixth portion; The third optical switching engine is used to deflect the plurality of third single-wavelength optical signals by a third angle and transmit them to the dispersion module, wherein the first angle and the third angle are different; The dispersion module is configured to transmit the fifth part of the plurality of third single-wavelength optical signals deflected at a third angle to the plurality of third sub-regions, and transmit the sixth part of at least one third single-wavelength optical signal to at least one first sub-region, the plurality of first sub-regions including the at least one first sub-region, the plurality of third single-wavelength optical signals deflected at the third angle include the at least one third single-wavelength optical signal, the fifth part of the plurality of third single-wavelength optical signals deflected at the third angle is reflected back to the dispersion module on the plurality of third sub-regions, and the sixth part of the at least one third single-wavelength optical signal is reflected back to the dispersion module on the at least one first sub-region; The dispersion module is further configured to combine the fifth parts of the plurality of third single-wavelength optical signals that have been reflected into a third multi-wavelength optical signal, and transmit the third multi-wavelength optical signal to the third output port, and to combine the sixth part of the at least one third single-wavelength optical signal that has been reflected into a fourth multi-wavelength optical signal, and transmit the fourth multi-wavelength optical signal to a direction other than the port included in the wavelength selective switch.

4. The wavelength selective switch according to claim 3, characterized in that: The first offset in the dispersion direction between the center of the i-th first sub-region and the center of the i-th third window is greater than or equal to 0 and less than or equal to the sum of the widths of 20 first sub-regions, i=1, 2, 3, ..., K, K is the number of the multiple first sub-regions.

5. The wavelength selective switch according to claim 3 or 4, characterized in that: The wavelength selective switch also includes a beam combiner and a deflection unit; The first optical switching engine is used to transmit the plurality of first single-wavelength optical signals deflected at a first angle to the beam combiner; The third optical switching engine is used to transmit the plurality of third single-wavelength optical signals deflected by a third angle to the deflection unit; The deflection unit is used to deflect the plurality of third single-wavelength optical signals transmitted by the third optical switching engine to the beam combiner; The beam combiner is used to transmit the multiple first single-wavelength optical signals transmitted by the first optical switching engine and the multiple third single-wavelength optical signals deflected by the deflection unit to the dispersion module.

6. The wavelength selective switch according to claim 5, characterized in that: The second offset in the dispersion direction between the i-th first single-wavelength optical signal and the i-th third single-wavelength optical signal transmitted by the combiner to the dispersion module is constrained by the first offset, and the first offset is the offset in the dispersion direction between the center of the i-th first sub-region and the center of the i-th third sub-region, i=1, 2, 3, ..., K, K is the number of the multiple first sub-regions.

7. The wavelength selective switch according to claim 5 or 6, characterized in that: The wavelength selective switch further comprises: a lens; The beam combiner is used to transmit the plurality of first single-wavelength optical signals transmitted by the first optical switching engine and the plurality of third single-wavelength optical signals deflected by the deflection unit to the lens; The lens is used to transmit the multiple first single-wavelength optical signals and the multiple third single-wavelength optical signals transmitted through the beam combiner to the dispersion module.

8. A method for transmitting an optical signal, characterized in that: The method is applied to a wavelength selective switch, the wavelength selective switch comprising: a first output port, a plurality of first input ports corresponding to the first output port, a first optical switching engine, a dispersion module, and a second optical switching engine, the second optical switching engine comprising a first area and a second area, the first area and the second area being adjacent, the first area comprising a plurality of first sub-areas corresponding to the first output port, the width of the second area being greater than or equal to 2.5 times the size of the light spot, the method comprising: The plurality of first input ports transmit a plurality of first single-wavelength optical signals to the first optical switching engine, each of the first single-wavelength optical signals comprising a first portion and a second portion; The first optical switching engine deflects the plurality of first single-wavelength optical signals by a first angle and transmits the signals to the dispersion module; The dispersion module transmits the first part of the plurality of first single-wavelength optical signals after being deflected at a first angle to the plurality of first sub-areas, transmits the second part of the plurality of first single-wavelength optical signals after being deflected at the first angle to the second area, and the first part of the plurality of first single-wavelength optical signals after being deflected at the first angle is reflected back to the dispersion module on the plurality of first sub-areas, and the spot size is equal to the spot size of each first single-wavelength optical signal in the port direction; The dispersion module combines the reflected first parts of the plurality of first single-wavelength optical signals into a first multi-wavelength optical signal, and transmits the first multi-wavelength optical signal to the first output port.

9. The method according to claim 8, characterized in that The wavelength selective switch further includes: a second output port and a plurality of second input ports corresponding to the second output port; the second optical switching engine further includes a third area, the third area is adjacent to the second area, the second area is located between the first area and the third area, and the third area includes a plurality of second sub-areas corresponding to the second output port; the method further includes: The plurality of second input ports transmit a plurality of second single-wavelength optical signals to the first optical switching engine, each second single-wavelength optical signal comprising a third portion and a fourth portion; The first optical switching engine deflects the plurality of second single-wavelength optical signals at a second angle and transmits the deflected signals to the dispersion module, wherein the first angle and the second angle are different; The dispersion module transmits the third part of the plurality of second single-wavelength optical signals after being deflected at the second angle to the plurality of second sub-areas, transmits the fourth part of the plurality of second single-wavelength optical signals after being deflected at the second angle to the second area, and the third part of the plurality of second single-wavelength optical signals after being deflected at the second angle is reflected back to the dispersion module on the plurality of second sub-areas; The dispersion module combines the reflected third parts of the plurality of second single-wavelength optical signals into a second multi-wavelength optical signal, and transmits the second multi-wavelength optical signal to the second output port.

10. The method according to claim 8, characterized in that The wavelength selective switch further includes a third optical switching engine, a third output port, and a plurality of third input ports corresponding to the third output port, the first output port and the plurality of first input ports belong to a first port group, the third output port and the plurality of third input ports belong to a second port group, the first port group and the second port group are arranged opposite to each other, and the second area includes a plurality of third sub-areas corresponding to the third output port; The method further comprises: The plurality of third input ports transmit a plurality of third single-wavelength optical signals to the third optical switching engine, each of the third single-wavelength optical signals comprising a fifth portion and a sixth portion; The third optical switching engine deflects the plurality of third single-wavelength optical signals at a third angle and transmits the deflected signals to the dispersion module, wherein the first angle and the third angle are different; The dispersion module transmits the fifth part of the plurality of third single-wavelength optical signals deflected by a third angle to the plurality of third sub-regions, and transmits the sixth part of at least one third single-wavelength optical signal to at least one first sub-region, the plurality of first sub-regions include the at least one first sub-region, the plurality of third single-wavelength optical signals deflected by the third angle include the at least one third single-wavelength optical signal, the fifth part of the plurality of third single-wavelength optical signals deflected by the third angle is reflected back to the dispersion module on the plurality of third sub-regions, and the sixth part of the at least one third single-wavelength optical signal is reflected back to the dispersion module on the at least one first sub-region; The dispersion module combines the reflected fifth parts of the plurality of third single-wavelength optical signals into a third multi-wavelength optical signal, and transmits the third multi-wavelength optical signal to the third output port, and combines the reflected sixth part of the at least one third single-wavelength optical signal into a fourth multi-wavelength optical signal, and transmits the fourth multi-wavelength optical signal to a direction other than the port included in the wavelength selective switch.

11. A single board, characterized in that: include: At least one wavelength selective switch according to any one of claims 1 to 7.

12. An optical switching device, characterized in that: It comprises a plurality of single boards, at least one of the plurality of single boards being the single board according to claim 11.

13. The optical switching device according to claim 12, characterized in that: The optical switching device is a reconfigurable optical fork multiplexer.

14. An optical network system, characterized in that: include: A plurality of optical switching devices, at least one of the plurality of optical switching devices is the optical switching device according to claim 12 or 13.

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