Wavelength selective switch, optical switching node, and communication system

Abstract

Embodiments of the present application provide a wavelength selective switch, an optical switching node, and a communication system, for use in reducing the number of devices comprised in the wavelength selective switch, and improving the integration level of the wavelength selective switch. The wavelength selective switch comprises an input fiber, a lens group, a dispersion unit, an optical switching engine, and an output fiber array. The dispersion unit comprises an optical metasurface structure; the input fiber is used for transmitting an input light beam to the lens group; the lens group is used for collimating the input light beam to obtain a first light beam, and transmitting the first light beam to the dispersion unit; the optical metasurface structure is used for splitting the first light beam to obtain multiple second light beams, and is further used for collimating the multiple second light beams to transmit the multiple collimated second light beams to the optical switching engine; and the optical switching engine is used for deflecting the transmission direction of each of the multiple second light beams, so as to obtain multiple output light beams, wherein the output light beams are configured to be output via the output fiber array.

Description

A wavelength selective switch, optical switching node and communication system

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on October 31, 2023, with application number 202311440589.2 and invention name “A wavelength selective switch, optical switching node and communication system”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The embodiments of the present application relate to the field of optical communication technology, and in particular to a wavelength selective switch, an optical switching node, and a communication system. Background Art

[0003] When optical networks use technologies like wavelength division multiplexing (WDM) to transmit light beams, optical switching nodes can be used to schedule the beam's transmission direction. These nodes primarily use wavelength selective switches (WSSs) to schedule the transmission direction at the wavelength level. WSSs are based on optical switching engines to deflect the beam's transmission direction.

[0004] The WSS comprises a fiber array, a dispersion-direction lens, a port-direction lens, a grism, and an optical switching engine. The fiber array is used to input a light beam, and the grism disperses the beam to produce multiple sub-beams. The dispersion-direction lens and the port-direction lens collimate the sub-beams along the dispersion and port directions, respectively. The optical switching engine deflects the aligned sub-beams in their transmission directions, and these deflected sub-beams are then output from the WSS via the fiber array.

[0005] However, the existing WSS includes a large number of components, which increases the difficulty of assembling the WSS, resulting in low assembly efficiency and poor integration of the WSS.

[0006] Summary of the Invention

[0007] The embodiments of the present application provide a wavelength selective switch, an optical switching node, and a communication system, which can reduce the number of components included in the wavelength selective switch and improve the integration of the wavelength selective switch.

[0008] In a first aspect, embodiments of the present application provide a wavelength selective switch, comprising: an input optical fiber, a lens assembly, a dispersion unit, an optical switching engine, and an output optical fiber array. The dispersion unit comprises an optical metasurface structure, comprising a plurality of nanostructures arranged along a first plane, wherein the first plane includes a dispersion direction and a port direction. The optical metasurface structure comprises a plurality of nanostructures arranged along the dispersion direction and along the port direction, respectively. First, the input optical fiber is configured to transmit an input light beam to the lens assembly, wherein the transmission direction of the input light beam intersects the first plane. Specifically, the transmission direction of the input light beam is perpendicular to the first plane. The lens assembly is then configured to collimate the input light beam to obtain a first light beam, which is then transmitted to the dispersion unit. The optical metasurface structure is then configured to decompose the first light beam along the dispersion direction to obtain multiple second light beams. The optical metasurface structure is further configured to collimate the multiple second light beams along the port direction, for transmission of the collimated multiple second light beams to the optical switching engine. Then, the optical switching engine is used to deflect the transmission direction of each second light beam in the multiple second light beams to obtain multiple output light beams, and the multiple output light beams are used to be output through the output optical fiber array.

[0009] The optical metasurface structure composed of multiple nanostructures, as described in this invention, can achieve both splitting of the first light beam and collimation of each second light beam along the port direction while reducing distortion of the first light beam. A single dispersion unit performs both splitting along the dispersion direction and collimation along the port direction, eliminating the need for a wavelength selective switch with a lens group having curvature along the port direction. This reduces the number of components included in the wavelength selective switch, easing the difficulty of assembling the wavelength selective switch and improving its assembly efficiency and integration.

[0010] Based on the first aspect, in an optional implementation, the optical paths of the multiple second light beams emitted from the dispersion unit have different projection directions in the second plane; the optical paths of the multiple second light beams emitted from the dispersion unit have different projection directions in a third plane, and the third plane intersects with the first plane and the second plane respectively.

[0011] Using this implementation method, the dispersion unit with an optical metasurface structure can decompose the first light beam along the dispersion direction to obtain multiple second light beams. Compared with the existing grating structure used only for dispersion, the dispersion unit with an optical metasurface structure can reduce the insertion loss in the process of decomposing the first light beam and improve the diffraction efficiency.

[0012] Based on the first aspect, in an optional implementation, the lens group is used to collimate the input light beam along a dispersion direction, the dispersion unit is used to collimate the second light beam along a port direction, and the dispersion direction intersects with the third plane, and the port direction intersects with the second plane.

[0013] As shown in this implementation, the collimation effect of the lens group along the dispersion direction and the collimation effect of the dispersion unit along the port direction ensure that each second light beam can be transmitted to the optical switching engine at a suitable angle and spot size, ensuring that the optical switching engine successfully deflects the transmission direction of each second light beam.

[0014] Based on the first aspect, in an optional implementation, the multi-path second light beam includes a first target beam and a second target beam, the first target beam forms a first light spot on the optical switching engine, and the second target beam forms a second light spot on the optical switching engine. In the second plane, the positions of the first light spot and the second light spot are separated from each other, and in the third plane, the positions of the first light spot and the second light spot at least partially overlap.

[0015] Using this implementation method, the dispersion unit with an optical metasurface structure can accurately transmit the first target light beam to the optical switching engine to form a first light spot, and accurately transmit the second target light beam to the optical switching engine to form a second light spot. The optical switching engine can accurately deflect the transmission direction of the first target light beam and the transmission direction of the second target light beam.

[0016] Based on the first aspect, in an optional implementation, the optical metasurface structure includes a plurality of units, each of the plurality of units includes at least one nanostructure, and the plurality of units include a first unit and a second unit, and the nanostructure included in the first unit is different from the nanostructure included in the second unit.

[0017] Using this implementation, the dispersion unit with an optical metasurface structure can decompose the first light beam along the dispersion direction to obtain multiple second light beams. Moreover, the dispersion unit with an optical metasurface structure can also collimate each second light beam along the port direction, eliminating the need for the wavelength selective switch to be configured with a lens group with curvature along the port direction, thereby reducing the number of components included in the wavelength selective switch.

[0018] Based on the first aspect, in an optional implementation, the nanostructure included in the first unit is different from the nanostructure included in the second unit, which refers to at least one of the following:

[0019] The number of nanostructures included in the first unit is different from the number of nanostructures included in the second unit, the size of the nanostructures included in the first unit is different from the size of the nanostructures included in the second unit, the arrangement form of the nanostructures included in the first unit is different from the arrangement form of the nanostructures included in the second unit, and the shape of the nanostructures included in the first unit is different from the shape of the nanostructures included in the second unit.

[0020] Using this implementation, the dispersion unit with an optical metasurface structure can decompose the first light beam along the dispersion direction to obtain multiple second light beams. Moreover, the dispersion unit with an optical metasurface structure can also collimate each second light beam along the port direction, eliminating the need for the wavelength selective switch to be configured with a lens group with curvature along the port direction, thereby reducing the number of components included in the wavelength selective switch.

[0021] Based on the first aspect, in an optional implementation, the optical metasurface structure includes multiple regions, each of the multiple regions includes multiple units, the multiple regions include a first region and a second region, the nanostructure included in the first region is different from the nanostructure included in the second region; the first region is used to receive a first output beam from the optical switching engine, and the second region is used to receive a second output beam from the optical switching engine, and the multi-path output beam includes the first output beam and the second output beam; the first region is also used to focus the first output beam along the port direction, and the focused first output beam is used to be output via a first output optical fiber, the second region is also used to focus the second output beam along the port direction, and the focused second output beam is used to be output via a second output optical fiber, and the output optical fiber array includes the first output optical fiber and the second output optical fiber.

[0022] In this implementation, the dispersion unit with an optical metasurface structure can combine the first output beams along the dispersion direction to obtain a first combined beam. Furthermore, the dispersion unit with an optical metasurface structure can focus the first output beam along the port direction, eliminating the need for a lens group with curvature along the port direction in the wavelength selective switch, thus reducing the number of components included in the wavelength selective switch. Similarly, the dispersion unit with an optical metasurface structure can combine the second output beams along the dispersion direction to obtain a second combined beam. Furthermore, the dispersion unit with an optical metasurface structure can focus the second output beam along the port direction, thus eliminating the need for a lens group with curvature along the port direction in the wavelength selective switch, thus reducing the number of components included in the wavelength selective switch.

[0023] Based on the first aspect, in an optional implementation, the nanostructure included in the first region is different from the nanostructure included in the second region, which refers to at least one of the following:

[0024] The number of nanostructures included in the first region is different from the number of nanostructures included in the second region, the size of the nanostructures included in the first region is different from the size of the nanostructures included in the second region, the arrangement form of the nanostructures included in the first region is different from the arrangement form of the nanostructures included in the second region, and the shape of the nanostructures included in the first region is different from the shape of the nanostructures included in the second region.

[0025] By adopting this implementation, the dispersion unit in the form of an optical metasurface structure can simultaneously have a beam combining effect along the dispersion direction and a focusing effect along the port direction.

[0026] Based on the first aspect, in an optional implementation, the dispersion unit includes a substrate, and the first surface of the substrate includes the optical metasurface structure.

[0027] Based on the first aspect, in an optional implementation, the second surface of the substrate includes at least one layer of coating, and the material of the substrate is different from the material of the coating.

[0028] By adopting this implementation, the dispersion unit including the coating can improve the diffraction efficiency in the process of scheduling the transmission direction of the input light beam and reduce the diffraction loss.

[0029] Based on the first aspect, in an optional implementation, the dispersion unit further includes a prism, a first surface of the prism faces the lens group, and a second surface of the prism is connected to the second surface of the substrate.

[0030] In this implementation, the prism is used to adjust the angle at which the first light beam is incident on the optical metasurface structure, thereby ensuring that the multiple second light beams emitted from the dispersion unit are linearly distributed, so that the multiple second light beams can be emitted from the dispersion unit evenly.

[0031] Based on the first aspect, in an optional implementation, the dispersion unit is used to transmit the collimated multiple second light beams to the optical switching engine, including: the optical metasurface structure is used to reflect the collimated multiple second light beams toward the optical switching engine, or the optical metasurface structure is used to transmit the collimated multiple second light beams to the optical switching engine.

[0032] With this implementation, the optical metasurface structure can be transmissive or reflective, thereby achieving flexibility in optical path design during input light beam scheduling.

[0033] In a second aspect, an embodiment of the present application provides an optical switching node, which includes multiple wavelength selective switches, and two different wavelength selective switches are connected by optical fibers. The wavelength selective switches are as described in the first aspect above, and are not described in detail.

[0034] In a third aspect, an embodiment of the present application provides a communication system, comprising an outer shell, the outer shell fixing a processing chip, an optoelectronic conversion module, and a wavelength selection switch, the processing chip, the optoelectronic conversion module, and the wavelength selection switch being connected in sequence, and the wavelength selection switch being as described in any one of the first aspects above; the processing chip being used to send a service electrical signal to the optoelectronic conversion module; the optoelectronic conversion module being used to convert the service electrical signal into the input light beam; and the wavelength selection switch being used to schedule the transmission direction of the input light beam to emit the output light beam.

[0035] In a fourth aspect, the present application provides an optical network, which includes a first communication system and a second communication system. For descriptions of the first communication system and the second communication system, please refer to the description of the third aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG1 is a structural diagram of an optical switching node provided by the present application;

[0037] FIG2 is a structural example diagram of an existing WSS;

[0038] FIG3 is an example diagram of the overall structure of the first embodiment of the WSS provided by this application;

[0039] FIG4 is a diagram illustrating an example structure of the WSS provided by this application in the second plane;

[0040] FIG5 is a structural example diagram of the WSS provided by this application in the third plane;

[0041] FIG6 is a structural diagram of an embodiment of a dispersion unit provided in the present application;

[0042] FIG7 a is a structural diagram illustrating a first embodiment of a nanorod provided in the present application;

[0043] FIG7 b is a structural diagram illustrating a second embodiment of a nanorod provided in the present application;

[0044] FIG7 c is a structural diagram illustrating a third embodiment of a nanorod provided in the present application;

[0045] FIG7 d is a structural diagram illustrating a fourth embodiment of a nanorod provided in the present application;

[0046] FIG8 is a diagram illustrating the overall structure of a second embodiment of the WSS provided by this application;

[0047] FIG9 is a diagram illustrating an example structure of an optical network according to an embodiment of the present application. DETAILED DESCRIPTION

[0048] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0049] This application provides an optical switching node for scheduling the transmission direction of light beams. The optical switching node can be a reconfigurable optical add-drop multiplexer (ROADM) or an optical cross-connect (OXC). The optical switching node primarily schedules the transmission direction of light beams at the wavelength level using a WSS.

[0050] The structure of the optical switching node provided in this application is described with reference to FIG1 , which shows an exemplary structure of an optical switching node provided in this application. This example uses a ROADM as an example optical switching node for illustrative purposes. This example does not limit the specific network structure of the ROADM. For example, the ROADM can adopt a chain, ring, or mesh network structure. FIG1 illustrates an exemplary network structure of the ROADM using a mesh network as an example.

[0051] This example uses a ROADM with eight WSSs (i.e., WSS1, WSS2, through WSS8) located at different locations. This example does not limit the number of WSSs included in the ROADM or their locations. The WSSs at different locations are used to schedule beam transmission directions.

[0052] Taking WSS1 as an example, WSS1 can send an optical beam to any WSS included in the ROADM that is connected to WSS1 via optical fiber to implement scheduling of optical beams in different transmission directions. For example, in the ROADM, WSS4, WSS6, and WSS8 are connected to WSS1 via optical fiber. Then, WSS1 can send an optical beam to any WSS among WSS4, WSS6, and WSS8. This example uses the example of WSS1 being connected to WSS4, WSS6, and WSS8 via optical fiber for illustrative purposes only, without limitation. In other examples, WSS1 can also be connected to any WSS among WSS2, WSS3, WSS5, and WSS7 included in the ROADM via optical fiber.

[0053] The following continues to use WSS1 and WSS4 as examples to illustrate the process of scheduling the transmission direction of the light beam:

[0054] First light beam 111, transmitted along direction 101, is input to WSS1 via its input optical fiber. WSS1 schedules the beam's transmission direction, and second light beam 112 is output via WSS1's output optical fiber. WSS1's output optical fiber is optically connected to WSS4, and WSS1 transmits second light beam 112 to WSS4. Second light beam 112 is output from an output optical fiber included in WSS4, and second light beam 112 output from WSS4 is transmitted along direction 102. In this example, direction 101 differs from direction 102. As can be seen, the ROADM shown in Figure 1 can schedule the transmission direction of first light beam 111 from direction 101 to direction 102.

[0055] It can be understood that the optical switching engine included in the WSS is used to deflect the transmission direction of any input wavelength or any group of wavelengths, so that the deflected wavelength is output from any output optical fiber.

[0056] To better understand the WSS provided by the embodiments of the present application, the following first describes an existing WSS in conjunction with FIG2 . FIG2 is a structural example diagram of an existing WSS. The existing WSS includes an optical fiber array 201, a spot shaping and polarization splitting component 202, a dispersion direction lens 203, a port direction lens 204, a prism 205, and an optical switching engine 206. An input light beam 211 is input into the WSS through the input optical fiber in the optical fiber array 201. The spot shaping and polarization splitting component 202 shapes and processes the polarization state of the input light beam 211 to output a processed light beam 212. The dispersion direction lens 203 and the port direction lens 204 collimate the processed light beam 212 along the dispersion direction and the port direction, respectively, to obtain a collimated light beam 213. The prism 205 disperses the collimated light beam 213 to obtain multiple sub-beams, such as sub-beam 214 and sub-beam 215. The port direction lens 204 and the dispersion direction lens 203 collimate the sub-beams along the port direction and the dispersion direction, respectively, to obtain collimated sub-beams. The optical switching engine 206 deflects the transmission direction of each collimated sub-beam to obtain multiple deflected sub-beams, such as deflected sub-beam 216 and deflected sub-beam 217. The dispersion direction lens 203 and the port direction lens 204 focus each deflected sub-beam to obtain a focused sub-beam. The grism 205 combines the focused sub-beams to obtain a combined beam. The port direction lens 204 and the dispersion direction lens 203 focus the combined beam to obtain an output beam, which is transmitted to an output fiber included in the fiber array. The output fiber is used to emit the output beam. It can be understood that the existing WSS needs to independently configure a dispersion direction lens with curvature in the dispersion direction and a port direction lens with curvature in the port direction, resulting in a large number of components included in the existing WSS, increasing the difficulty of assembling the WSS, resulting in low assembly efficiency and poor integration of the WSS.

[0057] The WSS provided in the embodiment of the present application does not need to be configured with a port direction lens having a curvature in the port direction, which effectively improves the integration of the WSS. The structure of the WSS provided in this embodiment is described below, wherein Figure 3 is an example diagram of the overall structure of the first embodiment of the WSS provided in this application. Figure 4 is an example diagram of the structure of the WSS provided in this application in the second plane. Figure 5 is an example diagram of the structure of the WSS provided in this application in the third plane. The WSS shown in Figure 3 is located in a coordinate system XYZ with O as the coordinate origin. The second plane YOZ described in Figure 4 specifically includes the Y axis and the Z axis of the XYZ coordinate system. The third plane XOZ described in Figure 5 specifically includes the X axis and the Z axis of the XYZ coordinate system.

[0058] The WSS shown in this embodiment includes a fiber array (FA) 301, a dispersion direction lens group, a dispersion unit 304, and an optical switching engine 305. The fiber array shown in this embodiment includes one or more input optical fibers, and this embodiment does not limit the number of input optical fibers included in the fiber array. The fiber array also includes an output optical fiber array, which includes multiple output optical fibers, and this embodiment does not limit the number of output optical fibers included in the output optical fiber array. FA301 is located at or near the front focal plane of the dispersion unit 304. The optical switching engine 305 is located at or near the back focal plane of the dispersion unit 304. Therefore, FA301, the dispersion unit 304, and the optical switching engine 305 constitute a 2f optical system.

[0059] Optionally, the WSS shown in this embodiment further includes a beam shaping and polarization splitting component 302. An input optical fiber is used to transmit an input light beam 311 to the beam shaping and polarization splitting component 302. In this embodiment, the input light beam 311 is a WDM signal light. In this embodiment, the transmission direction of the input light beam 311 emitted from the input optical fiber 311 coincides with the Z axis in the XYZ coordinate system. It should be noted that this embodiment uses the transmission direction of the input light beam 311 coinciding with the Z axis as an example. In other examples, the transmission direction of the input light beam 311 may also have a certain angle with the Z axis, which is not limited in this embodiment.

[0060] The beam shaping and polarization splitting component 302 is used to shape the input light beam 311 and adjust the polarization state of the input light beam 311. This embodiment does not limit the description of the function of the beam shaping and polarization splitting component 302, and corresponding adjustments can be made according to the design of the WSS. For example, the beam shaping and polarization splitting component 302 can adjust the spot of the input light beam 311 from a circular spot to an elliptical spot, so that the spot of the input light beam 311 emitted from the beam shaping and polarization splitting component 302 is elliptical, and is used to separate the input light beam 311 into two beams with orthogonal polarization states, and adjust the polarization states of the two beams to be consistent, and output from the beam shaping and polarization splitting component 302. It should be understood that this embodiment does not limit the spot shape and polarization state of the light beam emitted from the beam shaping and polarization splitting component 302. This embodiment does not limit the device type of the beam shaping and polarization splitting component 302. For example, the beam shaping and polarization splitting component 302 may include at least one of a crystal, a prism, a polarization grating, a micro lens array (MLA), a diffraction element, and a lens group.

[0061] The input light beam 311 emitted from the beam shaping and polarization splitting component 302 is transmitted to the dispersion direction lens group. This embodiment does not limit the specific number of lenses included in the dispersion direction lens group. In the example shown in FIG3 , the dispersion direction lens group includes a first lens 303. In the examples shown in FIG4 and FIG5 , the dispersion direction lens group includes a first lens 303 and a second lens 306. In the example shown in FIG3 , the first lens 303 can perform the functions performed by the first lens 303 and the second lens 306 in the examples shown in FIG4 and FIG5 . The first lens 303 shown in this embodiment is used to collimate the input light beam 311 to obtain a first light beam 312, and transmit the first light beam 312 to the dispersion unit 304. The following describes the process of the first lens 303 collimating the input light beam 311 to obtain the first light beam 312. Specifically, the first lens 303 is used to collimate the input light beam 311 along the dispersion direction to obtain the collimated first light beam 312. This embodiment takes the example of the dispersion direction coinciding with the Y-axis in the coordinate system XYZ. It should be noted that in other examples, the dispersion direction may also have a certain angle with the Y-axis, which is not specifically limited. Along this dispersion direction, the input light beam 311 enters the first lens 303 at a first divergence angle, and the first light beam 312 emerges from the first lens 303 at a second divergence angle. Due to the collimating effect of the first lens 303 on the input light beam 311, the first divergence angle is greater than the second divergence angle. Due to the collimating effect of the first lens 303 along the dispersion direction shown in this embodiment, the first light beam 312 has a very small second divergence angle. The collimating effect of the first lens 303 described in this embodiment causes the waist of the input light beam 311 to be smaller than the waist of the first light beam 312 along the dispersion direction. The waist of the input light beam 311 along the dispersion direction refers to the position in the input light beam 311 where the light intensity is the highest along the dispersion direction, and is also the position where the beam diameter of the input light beam 311 is the smallest. At the waist, the light intensity distribution exhibits the characteristics of a Gaussian distribution. For the description of the waist of the first light beam 312 , please refer to the description of the waist of the input light beam 311 , and detailed description is omitted here.

[0062] This embodiment uses the example of a cylindrical lens having curvature in the dispersion direction as the first lens 303. In other examples, the first lens 303 may also be a spherical lens, a sphero-cylindrical lens, an aspherical lens, or an aspheric cylindrical lens. Furthermore, the first lens 303 of this embodiment may be a reflective lens (such as shown in FIG. 3 ) or a transmissive lens (such as shown in FIG. 4 and FIG. 5 ), without further limitation. As shown in FIG. 4 and FIG. 5 , the first lens 303 shown in FIG. 4 has curvature along the dispersion direction (e.g., coinciding with the Y-axis), while the first lens 303 shown in FIG. 5 does not have curvature along the port direction (e.g., coinciding with the X-axis).

[0063] The dispersion unit 304 shown in this embodiment is used to decompose the first light beam 312 incident on the dispersion unit 304 into multiple second light beams with different wavelengths. This embodiment does not limit the number of second light beams. The dispersion unit 304 shown in this embodiment has two functions:

[0064] Function 1: The dispersion unit 304 has a wavelength-based light splitting function.

[0065] As shown in Figures 3 and 4, the dispersion unit 304 decomposes the first light beam 311 into a first target light beam 313 and a second target light beam 314 in the second plane YOZ. The wavelength of the first target light beam 313 is different from the wavelength of the second target light beam 314. The first target light beam 313 and the second target light beam 314 emitted from the dispersion unit 304 are dispersed along the dispersion direction. This embodiment takes the dispersion direction coinciding with the Y axis in the coordinate system XYZ as an example. In other examples, the dispersion direction may also have a certain angle with the Y axis. It should be clear that this embodiment does not limit the number of second light beams emitted after the first light beam 311 is decomposed by the dispersion unit 304. For example, the first light beam 312 is decomposed into N second light beams by the dispersion effect of the dispersion unit 304 along the dispersion direction. The wavelengths of different second light beams are different from each other. Then, the N second light beams emitted from the dispersion unit are λ1, λ2 to λ N , N is any integer greater than 2.

[0066] As shown in conjunction with Figures 3 and 5 , taking the first target beam and the second target beam included in N second light beams as an example, within the third plane XOZ, the first target beam 313 is emitted from the dispersion unit 304 at a first emission angle, and the second target beam 314 is emitted from the dispersion unit 304 at a second emission angle. The third plane XOZ includes the X-axis and the Z-axis of the XYZ coordinate system. For example, the first emission angle is the angle between the first target beam 313 and the second plane YOZ. For another example, the first emission angle is the angle between the first target beam 313 and the extension of the first beam 312 within the third plane XOZ. The second emission angle is the angle between the second target beam 314 and the second plane YOZ. For another example, the second emission angle is the angle between the second target beam 314 and the extension of the first beam 312 within the third plane XOZ. This embodiment takes the example that the first emission angle is equal to the second emission angle. In other examples, the first emission angle and the second emission angle may also be approximately equal, which will not be described in detail in this embodiment.

[0067] As shown in Figures 3 and 4 , within the second plane YOZ, the first target beam 313 is emitted from the dispersion unit 304 at a third emission angle, and the second target beam 314 is emitted from the dispersion unit 303 at a fourth emission angle. The second plane YOZ includes the Y-axis and the Z-axis of the XYZ coordinate system. For example, the third emission angle is the angle between the first target beam 313 and the third plane XOZ. Alternatively, the third emission angle is the angle between the first target beam 313 and the extension of the first beam 312 within the second plane YOZ. The fourth emission angle is the angle between the second target beam 314 and the third plane XOZ. Alternatively, the fourth emission angle is the angle between the second target beam 314 and the extension of the first beam 312 within the second plane YOZ. The third emission angle shown in this embodiment is different from the fourth emission angle.

[0068] As shown in Figures 3 to 5 , because the third emission angle is different from the fourth emission angle, the optical paths of the first target beam 313 and the second target beam 314 have different projection directions within the second plane YOZ. Specifically, multiple parallel projection lines illuminate the optical path of the first target beam 313 to form a first orthographic projection within the second plane YOZ, with each projection line perpendicular to the second plane YOZ. The propagation direction of the first target beam 313 is the same as the direction of the first orthographic projection. For example, as shown in Figure 4 , the propagation direction of the first target beam 313 is toward the second lens 306, so the direction of the first orthographic projection is also toward the second lens 306. Multiple parallel projection lines illuminate the optical path of the second target beam 314 to form a second orthographic projection within the second plane YOZ. The propagation direction of the second target beam 314 is the same as the direction of the second orthographic projection. In this embodiment, the optical paths of the first target beam 313 and the second target beam 314 have different projection directions within the second plane YOZ. This means that the orientation of the first orthographic projection is different from that of the second orthographic projection, that is, the first orthographic projection and the second orthographic projection are at an angle within the second plane YOZ. Because the first and second exit angles are equal, the optical paths of the first target beam 313 and the second orthographic projection have the same projection direction within the third plane XOZ. Specifically, multiple parallel projection lines illuminate the optical path of the first target beam 313 to form a third orthographic projection within the third plane XOZ, with each projection line being perpendicular to the third plane XOZ. The propagation direction of the first target beam 313 is the same as the orientation direction of the third orthographic projection. Multiple parallel projection lines illuminate the optical path of the second target beam 314 to form a fourth orthographic projection within the third plane XOZ. The propagation direction of the second target beam 314 is the same as the orientation direction of the fourth orthographic projection. The optical paths of the first target light beam 313 and the second target light beam 314 shown in this embodiment have the same projection direction in the third plane XOZ, which means that the direction of the third orthographic projection is the same as and coincides with the direction of the fourth orthographic projection.

[0069] Function 2: the dispersion unit 304 has the function of collimating each second light beam along the port direction.

[0070] The example shown in this embodiment is that the port direction coincides with the X-axis in the coordinate system XYZ. In other examples, the port direction may also have a certain angle with the X-axis, which is not specifically limited. In the third plane XOZ, the first light beam 312 enters the dispersion unit 304 at a third divergence angle, and the first target light beam 313 emerges from the dispersion unit 304 at a fourth divergence angle. The dispersion unit 304 collimates the first light beam 312 along the port direction. Therefore, the third divergence angle is greater than the fourth divergence angle. The dispersion unit 304 collimates each second light beam along the port direction, so that each second light beam can be collimated along the port direction and then transmitted to the optical switching engine 305. For the description of the collimation of the dispersion unit 304 along the port direction, please refer to the description of the collimation of the first lens 303 along the dispersion direction, and the details are not repeated here.

[0071] The structure of the dispersion unit 304 for implementing the above-mentioned functions 1 and 2 is described below:

[0072] Optional structure 1 of the dispersion unit 304:

[0073] The structure of the dispersion unit 304 provided in this embodiment is described below with reference to Figures 3 and 6 , wherein Figure 6 is a diagram illustrating an exemplary embodiment of the dispersion unit provided in this application. The dispersion unit 304 shown in this embodiment includes a substrate 601 having a first surface and a second surface. The second surface of substrate 601 faces the first lens 303, and the first surface of substrate 601 includes an optical metasurface structure 610. It should be noted that this embodiment uses the example of the first surface of substrate 601 including the optical metasurface structure 610. In other examples, the optical metasurface structure 610 may also be located on the second surface of substrate 601. The optical metasurface structure 610 implements the light-splitting function of the dispersion unit 304 as shown in Function 1 above, and the function of collimating each second light beam along the port direction as shown in Function 2. Specifically, the optical metasurface structure 610 includes a plurality of nanostructures arranged along a first plane XOY. Each nanostructure may be a nanofin or a nanopillar. This embodiment uses the example of each nanostructure being a nanopillar. For example, Figure 7a is a structural example diagram of the first embodiment of the nanocolumn provided in this application. The nanocolumn 701 included in the dispersion unit 304 shown in Figure 7a can be a square column. For another example, Figure 7b is a structural example diagram of the second embodiment of the nanocolumn provided in this application. The nanocolumn 702 included in the dispersion unit 304 shown in Figure 7b can be a cross-shaped column. For another example, Figure 7c is a structural example diagram of the third embodiment of the nanocolumn provided in this application. The nanocolumn 703 included in the dispersion unit 304 shown in Figure 7c can be cylindrical. It should be understood that this embodiment does not limit the description of the nanocolumn structure. In other examples, the nanocolumns can also be elliptical columns, triangular columns, square columns, etc. The optical metasurface structure 610 composed of a plurality of nanocolumns is an artificial composite material with a nanostructure, which greatly reduces the weight and thickness of the dispersion unit 304. Furthermore, the dispersion unit 304 decomposes the first light beam 311 into multiple second light beams based on the optical metasurface structure 610. The nanostructures included in the optical metasurface structure 610 are typically subwavelength in height, thus enabling the first light beam 311 to be split (as described in Function 1) and collimated along the port direction for each second light beam (as described in Function 2) while reducing distortion of the first light beam 311. Continuing with FIG6 , the optical metasurface structure 610 specifically includes multiple nanostructures arranged in the dispersion direction and multiple nanostructures arranged along the port direction. The refractive index distribution of the multiple nanostructures included in the optical metasurface structure 610 is equivalent to a refractive index distribution capable of achieving Functions 1 and 2 described above.

[0074] Specifically, the dispersion unit 304 shown in this embodiment includes M units, each unit includes at least one nanostructure, and M is any integer greater than 1. For example, the value of M shown in this embodiment can be any value such as 2000 or 10000. This embodiment takes the example of each unit including one nanostructure. The M units include a first unit and a second unit, and the first nanostructure included in the first unit is different from the second nanostructure included in the second unit. The first unit and the second unit are any two units among the M units. The first nanostructure included in the first unit is different from the second nanostructure included in the second unit, which means at least one of the following:

[0075] The number of first nanostructures included in the first unit is different from the number of second nanostructures included in the second unit, the size of the first nanostructure is different from the size of the second nanostructure, the arrangement form of the first nanostructure is different from the arrangement form of the second nanostructure, and the shape of the first nanostructure is different from the shape of the second nanostructure.

[0076] Among them, the size of the first nanostructure includes the height of the first nanostructure and / or the cross-sectional diameter of the first nanostructure. The height of the first nanostructure refers to the height of the first nanostructure along the Z-axis direction in the XYZ coordinate system. The cross-section of the first nanostructure refers to the cross-section obtained by cutting the first nanostructure with a plane parallel to the first plane XOY as a section. For the description of the size of the second nanostructure, please refer to the description of the size of the first nanostructure, and the details are not repeated here. The arrangement form of the first nanostructure refers to the density of the first nanostructure included in the first unit, and / or the distance between two adjacent first nanostructures included in the first unit. For the description of the arrangement form of the second nanostructure, please refer to the description of the arrangement form of the first nanostructure, and the details are not repeated here. For the description of the shape of the first nanostructure, please refer to Figures 7a to 7c, and the details are not repeated here.

[0077] Optional structure 2 of the dispersion unit 304:

[0078] Continuing to refer to FIG6 , the dispersion unit 304 further includes a prism 620, wherein the first surface of the prism 620 faces the first lens, and the second surface of the prism 620 is connected to the second surface of the substrate 601. Specifically, the second surface of the prism 620 is bonded to the second surface of the substrate 601 by optical glue or the like. The prism 620 shown in this embodiment is used to adjust the angle at which the first light beam 312 is incident on the optical metasurface structure 610, thereby ensuring that the multiple second light beams emitted from the dispersion unit 304 are linearly distributed, so that the multiple second light beams can be uniformly emitted from the dispersion unit 304. The linear distribution of the multiple second light beams means that, among the multiple second light beams emitted from the dispersion unit 304, the angle between any two adjacent second light beams is within a preset angle range. For example, taking the preset range of 15 degrees as an example, N second light beams are emitted from the dispersion unit 304, specifically λ1, λ2 to λ N , N is any integer greater than 2. The angle between λ1 and λ2 emitted from the dispersion unit 304 is 0.1 degrees. Similarly, the angle between λ1 and λ2 emitted from the dispersion unit 304 is 0.1 degrees. N-1 and λ N The angle between them is also 15 degrees, and the multiple second light beams emitted from the dispersion unit 304 are linearly distributed. It should be noted that this embodiment takes the prism 620 as a triangular prism as an example, which is not limited to a specific embodiment. For example, the prism 620 can also be a right-angle prism or a pentagonal prism.

[0079] Optional structure 3 of the dispersion unit 304:

[0080] Figure 7d is a diagram illustrating the structure of the fourth embodiment of the nanorods provided herein. Based on the aforementioned optional structure 1 or optional structure 2 of the dispersion unit 304, the second surface of the substrate 601 includes at least one layer of coating 710. The material of the substrate 601 shown in this embodiment is different from the material of the coating 710. For example, the substrate 601 can be made of silicon (Si) or silicon dioxide (SiO2), while the coating 710 can be made of silicon nitride (Si3N4) or titanium dioxide (TiO2). The dispersion unit 304 including the coating can improve the diffraction efficiency during the process of adjusting the transmission direction of the input light beam and reduce diffraction loss.

[0081] The dispersion unit 304 shown in this embodiment, through at least one of the size, distribution, or shape of each nanostructure, can cause different nanostructures to generate different propagation modes or resonance modes. When a first light beam passes through nanostructures with different propagation modes or resonance modes, each second light beam emitted from the optical metasurface structure will have a different phase. This embodiment uses a reflective dispersion unit 304 as an example. That is, the optical metasurface structure included in the dispersion unit 304 is a reflective optical metasurface structure. Then, when the first light beam passes through nanostructures with different propagation modes or resonance modes, each second light beam reflected from the optical metasurface structure will have a different reflection phase, effectively improving the reflectivity. At least one of the optical metasurface structure and substrate shown in this embodiment is used to implement a reflective optical metasurface structure. For example, the optical metasurface structure can be made reflective by adjusting the material, arrangement, or shape of the nanostructures included in the optical metasurface structure. Alternatively, the optical metasurface structure can be made reflective by adjusting the substrate material.

[0082] This embodiment can change the phase distribution of the optical metasurface structure by adjusting the size of the nanostructures. For example, if the size of the nanostructures included in the optical metasurface structure increases from small to large, the phase change range can cover a phase change of 0-2π. It can be understood that by setting the size of the nanostructures, the phase distribution of the optical metasurface structure can be adjusted, the dispersion unit can decompose the first light beam along the dispersion direction to obtain multiple second light beams, and the transmission direction of each second light beam emitted by the dispersion unit can be precisely controlled, thereby achieving the purpose of collimating each second light beam along the port direction. The above example uses the dispersion unit adjusting the size of the nanostructures to adjust the phase distribution of the optical metasurface structure. In other examples, the phase distribution of the optical metasurface structure can also be adjusted by adjusting at least one of the size, arrangement, or shape of the nanostructures.

[0083] The multiple second light beams emitted from the dispersion unit 304 are transmitted to a dispersion directional lens group, which is used to focus each second light beam along the dispersion direction to obtain multiple third light beams. For example, the first lens 303 shown in Figure 3 focuses the first target light beam 313 to obtain the third light beam 315, and the first lens 303 focuses the second target light beam 314 to obtain the third light beam 316. In the examples shown in Figures 4 and 5, the second lens 306 focuses the first target light beam 313 to obtain the third light beam 315, and the second lens 306 focuses the second target light beam 314 to obtain the third light beam 316. The focusing effect of the second lens 306 described in this embodiment results in the beam waist of the first target light beam 313 being larger than the beam waist of the third light beam 315 along the dispersion direction. For a description of the beam waist, please refer to the above description of the beam waist of the first light beam 312, and the details are not repeated here. As shown in Figures 3 and 4 , within the second plane YOZ, third light beams 315 and 316 are transmitted to the optical switching engine 305 along different directions. Third light beam 315 irradiates the first switching region of the optical switching engine 305 to form a first light spot 351, while third light beam 316 irradiates the second switching region of the optical switching engine 305 to form a second light spot 352. Due to the collimation effect of the dispersion unit 304 along the port direction and the focusing effect of the dispersion-direction lens group along the dispersion direction, the first light spot 351 and the second light spot 352 are separated from each other within the second plane YOZ. As shown in Figures 3 and 5 , within the third plane XOZ, third light beams 315 and 316 are transmitted to the optical switching engine 305 along the same direction. Within the third plane XOZ, the positions of the first light spot 351 and the second light spot 352 at least partially overlap. The surface of the optical switching engine 305 shown in this embodiment is parallel to the third plane XOZ. It can be understood that after the collimation effect of the dispersion unit 304 along the port direction and the focusing effect of the dispersion direction lens group along the dispersion direction, the optical switching engine 305 receives N wavelengths, namely λ1, λ2 to λ N N wavelengths irradiating the optical switching engine 305 form N light spots. In the third plane XOZ, the positions of the N light spots at least partially overlap. In the second plane YOZ, the positions of the N light spots are separated from each other.

[0084] The optical switching engine 305 shown in this embodiment is configured to deflect the propagation direction of each third light beam, so that the optical switching engine 305 emits multiple output light beams with deflected propagation directions. The optical switching engine 305 shown in this embodiment can be a liquid crystal on silicon (LCOS), a liquid crystal (LC) array chip, a microelectromechanical system (MEMS), a digital light processor (DLP), or a dual-axis MEMS. This embodiment uses the LCOS as an example. By applying a first voltage to a first switching region of the optical switching engine 305, the refractive index of the first switching region is changed, thereby deflecting the propagation direction of the third light beam 315 in the port direction, thereby emitting a first output light beam 361. By applying a second voltage to a second switching region of the optical switching engine 305, the refractive index of the second switching region is changed, thereby deflecting the propagation direction of the third light beam 316 in the port direction, thereby emitting a second output light beam 362. If the optical switching engine 305 shown in this embodiment is a MEMS, and the third light beam 315 is incident on the first reflector lens included in the MEMS, and the third light beam 316 is incident on the second reflector lens included in the MEMS, the first and second reflectors are controlled to rotate so that the first and second output light beams 361 and 362 are emitted from the MEMS at different output angles. If the optical switching engine 305 shown in this embodiment is a dual-axis MEMS, the dual-axis MEMS emits light from the optical switching engine 305 at different output angles based on the wavelengths of the first and second output light beams 361 and 362.

[0085] The output fiber array shown in this embodiment includes multiple output fibers. This embodiment does not limit the number of output fibers included in the output fiber array. For example, the output fiber array includes a first output fiber and a second output fiber. Within the second plane YOZ, the first output fiber and the second output fiber are positioned overlapping, and within the third plane XOZ, the first output fiber and the second output fiber are positioned separately. That is, along the port direction, the position of the first output fiber is different from the position of the second output fiber. It should be understood that the description of the arrangement of the output fiber array in this embodiment is an optional example and is not limiting. For example, the output fibers may have a certain curvature along the dispersion direction. For example, the positions of the multiple output fibers included in the output fiber array may be randomly arranged. For another example, the multiple output fibers included in the output fiber array may be arranged in a two-dimensional manner.

[0086] In this embodiment, taking the example of a first output beam 361 emitted from the optical switching engine 305 being deflected toward the first output fiber of the output fiber array, and a second output beam 362 emitted from the optical switching engine 305 being deflected toward the second output fiber of the output fiber array, the optical switching engine 305 deflects the transmission direction of the third beam 315 at a first deflection angle to emit the deflected first output beam 361, and deflects the transmission direction of the third beam 316 at a second deflection angle to emit the deflected second output beam 362. The first deflection angle corresponds to the position of the first output fiber, and the second deflection angle corresponds to the position of the second output fiber. This allows the first output beam 361 emitted from the optical switching engine 305 to be transmitted toward the first output fiber, and the second output beam 362 emitted from the optical switching engine 305 to be transmitted toward the second output fiber. Specifically, the first deflection angle may be the angle between the transmission direction of the third beam 315 and the transmission direction of the first output beam 361. The second deflection angle can be the angle between the propagation direction of the third light beam 316 and the propagation direction of the second output light beam 362. For example, within the third plane XOZ shown in FIG5 , the first deflection angle is different from the second deflection angle. Within the second plane YOZ shown in FIG4 , the first deflection angle and the second deflection angle can be the same. The magnitudes of the first deflection angle and the second deflection angle shown in this embodiment are related to the arrangement positions of the first output optical fiber and the second output optical fiber in the output optical fiber array.

[0087] The first output beam 361 and the second output beam 362 emitted from the optical switching engine 305 are transmitted to the second lens 306. The second lens 306 is used to collimate each output beam along the dispersion direction and send the collimated first output beam 361 and second output beam 362 to the dispersion unit 304. The collimation effect of the second lens 306 described in this embodiment causes the waist of the first output beam 361 to be larger than the waist of the collimated first output beam 361 along the dispersion direction. For the description of the waist, please refer to the above description of the waist of the input beam 311, and the details are not repeated here. For the description of the collimation of the second output beam 362 along the dispersion direction by the second lens 306, please refer to the description of the collimation of the first lens 306 along the dispersion direction, and the details are not repeated here.

[0088] The dispersion unit 304 receives the first output beam 361 and the second output beam 362 from the second lens 306 . The dispersion unit 304 has two functions.

[0089] Function 3: the dispersion unit 304 has a wavelength-based beam combining function.

[0090] For example, the dispersion unit 304 receives N output light beams from the second lens 306, where the wavelengths of the N output light beams are λ1, λ2, λ3, λN-1, and λN, respectively. It should be noted that this embodiment does not limit the value of N. This example assumes that the wavelength of the first output light beam 361 can be λ1, and the wavelength of the second output light beam 362 can be λN. The optical metasurface structure of the dispersion unit 304 includes multiple regions, specifically a first region and a second region. The first region is used to transmit the output light beam to the first output fiber, and the second region is used to transmit the output light beam to the second output fiber. In the second plane YOZ shown in FIG4 , since the first and second output fibers overlap, the first and second regions of the optical metasurface structure of the dispersion unit 304 overlap within the second plane YOZ. In the third plane XOZ shown in FIG5 , since the first and second fibers are separated, the first and second regions of the optical metasurface structure of the dispersion unit 304 are separated within the third plane XOZ. If λ1, λ2, and λ3 need to be emitted from the first output optical fiber, then λ1, λ2, and λ3 emitted from the second lens 306 are transmitted to the first region of the optical metasurface structure. If λN-1 and λN need to be emitted from the second output optical fiber, then λN-1 and λN emitted from the second lens 306 are transmitted to the second region of the optical metasurface structure. The first region of the optical metasurface structure is used to combine λ1, λ2, and λ3 to obtain a first combined light beam 371. The second region of the optical metasurface structure is used to combine λN-1 and λN to obtain a second combined light beam 372. The first region and the second region shown in this embodiment respectively include multiple nanostructures. For a description of the nanostructures, please refer to the above description of Function 1 and Function 2 of the dispersion unit 304, and the details are not repeated here.

[0091] Function 4: the dispersion unit 304 has the function of focusing each combined light beam along the port direction.

[0092] Since the dispersion unit 304 shown in this embodiment has a curvature along the port direction, the dispersion unit 304 shown in this embodiment can focus each combined light beam. For specific instructions on focusing along the dispersion direction, please refer to the instructions on focusing along the port direction by the second lens 306, and the details are not repeated here.

[0093] The first region and the second region of the dispersion unit shown in this embodiment are to achieve the above-mentioned functions 3 and 4. Therefore, the nanostructure included in the first region shown in this embodiment is different from the nanostructure included in the second region. The nanostructure included in the first region is different from the nanostructure included in the second region in at least one of the following:

[0094] The number of nanostructures included in the first region is different from the number of nanostructures included in the second region, the size of the nanostructures included in the first region is different from the size of the nanostructures included in the second region, the arrangement of the nanostructures included in the first region is different from the arrangement of the nanostructures included in the second region, and the shape of the nanostructures included in the first region is different from the shape of the nanostructures included in the second region. For a description of the number, size, arrangement, and shape of the nanostructures, please refer to the description of the number, size, arrangement, and shape of the first nanostructures included in the first unit shown above, and the details are not repeated here.

[0095] The first combined light beam 371 and the second combined light beam 372 emitted from the dispersion unit 304 are transmitted to the first lens 303. The first lens 303 is used to focus the first combined light beam 371 along the dispersion direction onto the first output fiber. The first lens 303 is also used to focus the second combined light beam 372 along the dispersion direction onto the second output fiber. For a description of the focusing along the dispersion direction by the first lens 303, please refer to the description of the focusing along the port direction by the dispersion unit 304, and the details are not repeated here. This embodiment uses the example of the first output fiber being different from the second output fiber. In other examples, the first output fiber and the second output fiber can be the same output fiber.

[0096] By adopting the WSS shown in this embodiment, the WSS can dispatch any wavelength input by the input optical fiber to any output optical fiber included in the output optical fiber array, thereby achieving the purpose of independently dispatching any wavelength to any output port. Moreover, the dispersion unit is a single device that has the functions of splitting along the dispersion direction and collimating along the port direction. Moreover, the dispersion unit also has the functions of combining along the dispersion direction and focusing along the port direction. Therefore, the WSS shown in this embodiment does not need to be configured with a lens group with curvature along the port direction, which reduces the number of components included in the WSS, reduces the difficulty of assembling the WSS, and improves the assembly efficiency of the WSS and the integration of the WSS. Because the WSS shown in this embodiment does not need to be configured with a lens group with curvature along the port direction, the complexity of the optical path in the process of WSS scheduling the light beam is simplified, and the accuracy of scheduling the light beam transmission direction is improved. The optical metasurface structure of the dispersion unit shown in this embodiment is made of nanostructure, which improves the diffraction efficiency and reduces the insertion loss of the WSS.

[0097] FIG3 shows an example in which the optical metasurface structure included in the dispersion unit is a reflective optical metasurface structure, and FIG8 shows an example in which the optical metasurface structure included in the dispersion unit is a transmissive optical metasurface structure. FIG8 is an overall structural example diagram of the second embodiment of the WSS provided in this application.

[0098] The WSS shown in this embodiment includes FA 801, a beam shaping and polarization splitting component 802, a dispersion direction lens group 803, a dispersion unit 804, and an optical switching engine 805. For a description of FA 801, beam shaping and polarization splitting component 802, dispersion direction lens group 803, and optical switching engine 805 shown in this embodiment, please refer to the corresponding description of Figure 3, and the details are not repeated here.

[0099] The input optical fiber included in FA801 transmits the input light beam 811 to the dispersion direction lens group 803. The dispersion direction lens group 803 collimates the input light beam 811 along the dispersion direction to obtain the collimated first light beam 812. The dispersion direction lens group 803 is used to transmit the first light beam 812 to the dispersion unit 804. For a description of the specific process, please refer to the description of the process of the dispersion unit receiving the first light beam corresponding to Figures 3 to 5, and the details are not repeated here. The dispersion unit 804 shown in this embodiment is used to decompose the first light beam 812 irradiated on the dispersion unit 804 into multiple second light beams with different wavelengths, and collimate each second light beam along the port direction. For a description of the specific decomposition and collimation process, please refer to the description of the dispersion unit decomposing the first light beam to obtain multiple second light beams and performing the collimation process corresponding to Figures 3 to 5, and the details are not repeated here.

[0100] The multiple second light beams shown in this embodiment specifically include a first target light beam 813 and a second target light beam 814. The optical metasurface structure included in the dispersion unit 804 is a transmissive optical metasurface structure. Therefore, the first target light beam 813 and the second target light beam 814 decomposed by the dispersion unit 804 are transmitted through the dispersion unit 804 and transmitted to the optical switching engine 805. If the dispersion unit 804 is transmissive, when the first light beam passes through nanostructures with different propagation modes or resonance modes, the second light beams transmitted from the optical metasurface structure will have different transmission phases, effectively improving the transmittance. The dispersion unit 804 shown in this embodiment can, through at least one of the size, distribution, or shape of each nanostructure, cause different nanostructures to produce different propagation modes or resonance modes. When the first light beam passes through nanostructures with different propagation modes or resonance modes, the second light beams transmitted from the optical metasurface structure will have different phases. At least one of the optical metasurface structure and the substrate shown in this embodiment is used to transmit the second light beam. For example, the optical metasurface structure can be made transmissive by adjusting the material, arrangement, or shape of the nanostructures included in the optical metasurface structure. Another example is that the optical metasurface structure can be made transmissive by adjusting the substrate material. For a description of the structure of the dispersion unit 804 shown in this embodiment, please refer to the description of the dispersion unit structure corresponding to FIG3 , and the details are not repeated here.

[0101] The first target light beam 813 and the second target light beam 814 emitted from the dispersion unit 804 are collimated and then transmitted to the optical switching engine 805. The optical switching engine 805 is configured to deflect the transmission direction of each second light beam, so that the optical switching engine 805 emits multiple output light beams with deflected transmission directions. The optical switching engine 805 deflects the transmission direction of the second light beam 813 by a first deflection angle to emit the deflected first output light beam 815. The optical switching engine 805 deflects the transmission direction of the second target light beam 814 by a second deflection angle to emit the deflected second output light beam 816. The first deflection angle corresponds to the position of the first output optical fiber, and the second deflection angle corresponds to the position of the second output optical fiber. For a description of the first deflection angle and the second deflection angle, please refer to the corresponding descriptions of Figures 3 to 5, and the details are not repeated here. The first output beam 815 and the second output beam 816 emitted from the optical switching engine 805 are transmitted to the dispersion unit 804. The dispersion unit 804 is used to combine the first output beam 815 to obtain a first combined beam 817. The dispersion unit 804 is also used to combine the second output beam 816 to obtain a second combined beam 818. The description of the combination of the dispersion unit 804 is shown in Figures 3 to 5, and the details are not repeated here. The first combined beam 817 is transmitted to the first output optical fiber to be emitted from the WSS, and the second combined beam 818 is transmitted to the second output optical fiber to be emitted from the WSS. For the specific process, please refer to the process of the combined beam being output from the output optical fiber corresponding to Figures 3 to 5, and the details are not repeated here.

[0102] By adopting the WSS shown in this embodiment, the WSS can dispatch any wavelength input by the input optical fiber to any output optical fiber included in the output optical fiber array, thereby achieving the purpose of independently dispatching any wavelength to any output port. Moreover, the dispersion unit is a device that has the functions of splitting light and collimating each second light beam along the port direction, and the dispersion unit also has the functions of combining beams and focusing each light beam along the port direction. Therefore, the WSS shown in this embodiment does not need to be configured with a lens group with curvature along the port direction, which reduces the number of components included in the WSS, reduces the difficulty of assembling the WSS, and improves the assembly efficiency of the WSS and the integration of the WSS. Because the WSS shown in this embodiment does not need to be configured with a lens group with curvature along the port direction, the complexity of the optical path in the process of WSS dispatching the light beam is simplified, and the accuracy of dispatching the light beam transmission direction is improved. Because the optical metasurface structure is made of nanostructures, the diffraction efficiency is improved and the insertion loss of the WSS is reduced.

[0103] The embodiment of the present application further provides an optical switching node. For the description of the optical switching node, please refer to the corresponding description of Figure 1 and the details will not be repeated here.

[0104] An embodiment of the present application further provides an optical network, the structure of which can be seen in FIG9 , which is an example diagram of the structure of an embodiment of the optical network provided by the present application.

[0105] The optical network 900 provided in this application specifically includes a first communication system 901 and a second communication system 902, and the first communication system 901 and the second communication system 902 are connected by an optical fiber. This example does not limit the number of communication systems included in the optical network 900. For example, the first communication system 901 can be connected to multiple second communication systems 902 through an optical splitter. This example does not limit the networking type of the optical network. For example, the optical network can adopt a ring network or a star network, etc. This example does not limit the network type applied by the optical network 900. For example, if the optical network 900 shown in this example is applied to a passive optical network (PON), then one of the communication systems in the first communication system 901 and the second communication system 902 can be an optical network unit (ONU) or an optical network terminal (ONT), and the other communication system in the first communication system 901 and the second communication system 902 can be an optical line terminal (OLT). If optical network 900 is applied to an optical transport network (OTN), both first communication system 901 and second communication system 902 can be OTN devices. The optical network 900 shown in this example can also be applied to a data center network (DCN) or a metropolitan area network, without specific limitations. Taking first communication system 901 as an example, this example does not limit the device type of first communication system 901. For example, first communication system 901 can be optical transmission equipment, optical access equipment, a router, a switch, a wireless base station, a wireless remote access device, a wireless baseband signal processing device, etc. It can also be a computing server (often referred to as a server), a high-performance computer (HPC), a storage server, or a memory resource pool. This example does not limit the type of first communication system 901; as long as first communication system 901 has electrical-to-optical conversion capabilities and an optical interface capable of connecting to optical fibers, it can be used. For a description of the type of second communication system 902, please refer to the description of first communication system 901; details are not repeated here.

[0106] Taking the first communication system 901 as an example, the first communication system 901 includes an outer shell, which fixes the device and one or more optoelectronic conversion modules. The outer shell also fixes one or more WSSs connected to the optoelectronic conversion module. Among them, the optoelectronic conversion module can also be referred to as an optical transceiver module or an optical module, etc. This example does not limit the number of devices included in the first communication system 901. The device and the first communication system 901 are integrated devices, or the device is an independent pluggable single board. This example does not limit the number of optoelectronic conversion modules included in the first communication system 901. The optoelectronic conversion module can be integrated with the device or pluggable on the single board of the device, etc., and there is no specific limitation. Specifically, the device has packaged a processing chip and a connector. Among them, the processing chip can be one or more chips, or one or more integrated circuits. For example, the processing chip can be one or more optical digital signal processors (oDSP), field-programmable gate arrays (FPGA), application specific integrated circuits (ASIC), system on chip (SoC), central processor unit (CPU), network processor (NP), microcontroller unit (MCU), programmable logic device (PLD), network card chip, storage interface chip or other integrated chips, or any combination of the above chips, or processing modules, etc., and the specific details are not repeated. The processing chip is connected to the optoelectronic conversion module through a connector, and the optical port of the optoelectronic conversion module is connected to the input optical fiber or output optical fiber of the WSS. For the description of the structure of the second communication system 902, please refer to the description of the structure of the first communication system 901, and the specific details are not repeated.

[0107] The optoelectronic conversion module described in this embodiment can be connected to one or more WSSs. For the description of the WSS structure, please refer to the above embodiment, and the details will not be repeated. The WSS and the optoelectronic conversion module can be an integrally formed structure. For example, the WSS can be plugged into the optoelectronic conversion module, etc., and the specific details are not limited. In the first communication system 901, the processing chip is used to send a first business electrical signal to the optoelectronic conversion module. The optoelectronic conversion module is used to convert the first business electrical signal into a first input light beam and transmit the first input light beam to the input optical fiber of the WSS. The WSS is used to schedule the transmission direction of the first input light beam to emit the output light beam. For a description of the specific process, please refer to the above description of the WSS scheduling the transmission direction of the input light beam, and the details will not be repeated. Continuing with the first communication system 901 as an example, the output optical fiber of the WSS receives a second input light beam from another communication system (for example, the second communication system 902), and the WSS schedules the transmission direction of the second input light beam to transmit it to the input optical fiber of the WSS. For a description of the specific process, please refer to the description of the WSS scheduling the transmission direction of the first input light beam of the first communication system 901, and the details will not be repeated.

[0108] An embodiment of the present application further provides a communication system. For the structure of the communication system, please refer to the description of the first communication system or the second communication system shown in Figure 9, and the details are not repeated here.

[0109] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A wavelength selective switch, characterized in that: include: An input optical fiber, a lens group, a dispersion unit, an optical switching engine, and an output optical fiber array, wherein the dispersion unit includes an optical metasurface structure, and the optical metasurface structure includes a plurality of nanostructures arranged along a first plane; The input optical fiber is used to transmit an input light beam to the lens group, and a transmission direction of the input light beam intersects with the first plane; The lens group is used to collimate the input light beam to obtain a first light beam, and transmit the first light beam to the dispersion unit; The optical metasurface structure is used to decompose the first light beam to obtain multiple second light beams, and the optical metasurface structure is also used to collimate the multiple second light beams to transmit the collimated multiple second light beams to the optical switching engine; The optical switching engine is used to deflect the transmission direction of each of the multiple second light beams to obtain multiple output light beams, and the multiple output light beams are used to be output through the output optical fiber array.

2. The wavelength selective switch according to claim 1, characterized in that: The optical paths of the multiple second light beams emitted from the dispersion unit have different projection directions in the second plane; the optical paths of the multiple second light beams emitted from the dispersion unit have different projection directions in the third plane, and the third plane intersects with the first plane and the second plane respectively.

3. The wavelength selective switch according to claim 2, characterized in that: The lens group is used to collimate the input light beam along a dispersion direction, and the dispersion unit is used to collimate the second light beam along a port direction, wherein the dispersion direction intersects with the third plane, and the port direction intersects with the second plane.

4. The wavelength selective switch according to claim 2 or 3, characterized in that: The multi-path second light beam includes a first target light beam and a second target light beam, the first target light beam forms a first light spot on the optical switching engine, the second target light beam forms a second light spot on the optical switching engine, in the second plane, the positions of the first light spot and the second light spot are separated from each other, and in the third plane, the positions of the first light spot and the second light spot at least partially overlap.

5. The wavelength selective switch according to any one of claims 1 to 4, characterized in that: The optical metasurface structure includes a plurality of units, each of the plurality of units includes at least one nanostructure, the plurality of units include a first unit and a second unit, and the nanostructure included in the first unit is different from the nanostructure included in the second unit.

6. The wavelength selective switch according to claim 5, characterized in that: The nanostructure included in the first unit is different from the nanostructure included in the second unit, which refers to at least one of the following: The number of nanostructures included in the first unit is different from the number of nanostructures included in the second unit, the size of the nanostructures included in the first unit is different from the size of the nanostructures included in the second unit, the arrangement of the nanostructures included in the first unit is different from the arrangement of the nanostructures included in the second unit, and the shape of the nanostructures included in the first unit is different from the shape of the nanostructures included in the second unit.

7. The wavelength selective switch according to claim 5 or 6, characterized in that: The optical metasurface structure includes a plurality of regions, each of the plurality of regions includes a plurality of the units, the plurality of regions include a first region and a second region, and the nanostructure included in the first region is different from the nanostructure included in the second region; The first area is used to receive a first output beam from the optical switching engine, the second area is used to receive a second output beam from the optical switching engine, and the multi-path output beam includes the first output beam and the second output beam; The first region is also used to focus the first output light beam along the port direction, and the focused first output light beam is used to be output through a first output optical fiber. The second region is also used to focus the second output light beam along the port direction, and the focused second output light beam is used to be output through a second output optical fiber. The output optical fiber array includes the first output optical fiber and the second output optical fiber.

8. The wavelength selective switch according to claim 7, characterized in that: The nanostructure included in the first region is different from the nanostructure included in the second region, which refers to at least one of the following: The number of nanostructures included in the first region is different from the number of nanostructures included in the second region, the size of the nanostructures included in the first region is different from the size of the nanostructures included in the second region, the arrangement form of the nanostructures included in the first region is different from the arrangement form of the nanostructures included in the second region, and the shape of the nanostructures included in the first region is different from the shape of the nanostructures included in the second region.

9. The wavelength selective switch according to any one of claims 1 to 8, characterized in that: The dispersion unit includes a substrate, and a first surface of the substrate includes the optical metasurface structure.

10. The wavelength selective switch according to claim 9, characterized in that: The second surface of the substrate includes at least one layer of coating, and the material of the substrate is different from that of the coating.

11. The wavelength selective switch according to claim 9 or 10, characterized in that: The dispersion unit further includes a prism, a first surface of the prism faces the lens group, and a second surface of the prism is connected to the second surface of the substrate.

12. The wavelength selective switch according to any one of claims 1 to 11, characterized in that: The dispersion unit is used to transmit the collimated multi-path second light beams to the optical switching engine, comprising: The optical metasurface structure is used to reflect the collimated multi-path second light beams toward the optical switching engine, or the optical metasurface structure is used to transmit the collimated multi-path second light beams toward the optical switching engine.

13. An optical switching node, characterized in that: The optical switching node comprises a plurality of wavelength selective switches, and two different wavelength selective switches are connected via optical fibers. The wavelength selective switches are as described in any one of claims 1 to 12.

14. A communication system, characterized in that: It comprises an outer shell, the outer shell fixes a processing chip, a photoelectric conversion module and a wavelength selection switch, the processing chip, the photoelectric conversion module and the wavelength selection switch are connected in sequence, and the wavelength selection switch is as claimed in any one of claims 1 to 12; The processing chip is used to send a service electrical signal to the photoelectric conversion module; The photoelectric conversion module is used to convert the business electrical signal into the input light beam; The wavelength selective switch is used to adjust the transmission direction of the input light beam to emit the output light beam.

Images