Wavelength selection switch and node device

Abstract

The embodiment of the invention provides a wavelength selection switch and a node device, relates to the field of optical communication, and aims to solve the problem that the number expansion of ports is affected by crosstalk and insertion loss between ports. The wavelength selective switch comprises an optical fiber array, and the optical fiber array comprises a first port and a plurality of second ports. The first port is arranged on the first reference line; the plurality of second ports are divided into a first part and a second part which are located on the two sides of the first reference line, and at least one of the first port, the first part and the second part is located on one side of the second reference line; and under the condition that the first port is arranged at the center of the optical path, the first part and the second part are asymmetrically arranged relative to the first port. The distance between the first port and the second reference line and the maximum distance between the second port in the first part and the second part and the second reference line are both smaller than or equal to two times of the port size. The wavelength selective switch can be a node device in an optical network.

Description

Technical Field

[0001] The present application relates to the field of optical communication technology, and in particular to a wavelength selective switch and a node device. Background Art

[0002] Optical networks are continuously developing and evolving towards large capacity, low latency, and intelligence. Optical switching technologies such as Reconfigurable Optical Add-Drop Multiplexer (ROADM) and Optical Cross-Connect (OXC) are key technologies for realizing optical networks with the above characteristics.

[0003] Wavelength Selective Switch (WSS) is the core device of ROADM and OXC. With the development of optical network, the number of ports of WSS is higher. However, the crosstalk between ports and port insertion loss in WSS affect the expansion of port number. Therefore, how to improve the influence of crosstalk between ports and port insertion loss on the expansion of port number has become an urgent problem to be solved. Summary of the invention

[0004] The embodiments of the present application provide a wavelength selective switch and a node device, which are used to improve the problem that crosstalk between ports and port insertion loss affect the expansion of the number of ports.

[0005] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides a wavelength selective switch, the wavelength selective switch comprising an optical fiber array and a spatial light modulator. The optical fiber array comprises a first port and a plurality of second ports.

[0007] The multiple second ports are divided into a first part and a second part located on both sides of a first reference line, and at least one of the first port, the first part and the second part is located on one side of the second reference line; when the first port is set at the center of the optical path, the first part and the second part are arranged asymmetrically relative to the first port.

[0008] In the optical fiber array, the distance of the first port relative to the second reference line is the first distance, the maximum distance of the second port in the first part relative to the second reference line is the second distance; the maximum distance of the second port in the second part relative to the second reference line is the third distance; the first distance, the second distance and the third distance are all less than or equal to 2 times the port size.

[0009] Among them, the center of the optical path is the position where the input light spot and the output light spot in the optical fiber array coincide when the spatial light modulator is used as a reflecting mirror; the first reference line is parallel to the dispersion direction, the second reference line is parallel to the port direction, and the intersection of the first reference line and the second reference line is the center of the optical path; the port size is the size of the first port in the dispersion direction.

[0010] In the wavelength selective switch provided in the embodiment of the present application, the multiple second ports of the optical fiber array include a first part and a second part respectively disposed on both sides of the first reference line, and the first part, the second part and the first port are arranged in an offset and asymmetric manner.

[0011] With such a design, on the one hand, by adopting a design in which the second port is provided on both sides of the first reference line, the bilateral deflection of the spatial light modulator can be used to switch the ports, so that more optical fiber ports can be supported when the diffraction deflection angle range supported by the spatial light modulator is the same, and the application scenarios of large ports, such as 64D, 128D, etc., can be met. Or, when the number of optical fiber ports is the same, it is beneficial to reduce the port insertion loss.

[0012] On the other hand, the biased, asymmetric arrangement of the optical fiber array helps to improve the situation where the diffracted light beams of the crosstalk order enter the optical fiber port in the wavelength selective switch in which the spatial light modulator adopts bilateral deflection for port switching, thereby improving the problem of crosstalk between optical fiber ports and helping to improve the isolation and directivity of the wavelength selective switch.

[0013] Furthermore, by limiting the first distance, the second distance and the third distance to be less than or equal to 2 times the port size, the diffraction deflection angle of the spatial light modulator in the dispersion direction can be limited; thereby, while ensuring the compactness of the port arrangement in the optical fiber array, the requirements for the diffraction deflection angle range of the spatial light modulator in the dispersion direction can be reduced, which is beneficial to reducing port insertion loss and improving the performance of the wavelength selective switch.

[0014] The first port may be located at one side of the first reference line or on the first reference line; further, the first port may be arranged at the center of the optical path.

[0015] In some embodiments, the first part and the second part each include at least two second ports, wherein the second ports in the first part are arranged along a straight line parallel to the second reference line, and the second ports in the second part are arranged along a straight line parallel to the second reference line.

[0016] In the wavelength selective switch provided in the embodiment of the present application, the second ports in the first part and the second part are arranged in a straight line, and the arrangement straight line is parallel to the second reference line. With such a design, on the one hand, the optical fiber ports arranged in a straight line are easier to manufacture and ensure position accuracy, thereby reducing the difficulty of manufacturing the optical fiber array; on the other hand, the parallel arrangement with the second reference line is more conducive to port switching, which can reduce the complexity of the port switching process, so that the port switching can be realized more quickly and accurately, which is conducive to improving the performance of the wavelength selective switch.

[0017] In some embodiments, the first port, the first part and the second part are located on the same side of the second reference line, and the orthographic projection positions on the first reference line are the same. Such a design can reduce the complexity of the port switching process while achieving bilateral deflection, avoiding crosstalk levels from entering the optical fiber port and reducing port insertion loss, so that port switching can be achieved more quickly and accurately, which is conducive to improving the performance of the wavelength selective switch.

[0018] In some embodiments, the first port, the second port in the first part, and the second port in the second part are at equal distances from the second reference line, and are all equal to 0.5 times the port size. This design can reduce the requirements for the diffraction deflection angle range of the spatial light modulator in the dispersion direction while ensuring the compactness of the port arrangement in the optical fiber array, which is beneficial to reducing port insertion loss and improving the performance of the wavelength selective switch.

[0019] In some embodiments, the first part and the second part have the same orthographic projection position on the first reference line, and the first port and the first part have different orthographic projection positions on the first reference line. With such a design, in some scenarios, while achieving bilateral deflection and improving crosstalk problems, a one-dimensional diffraction grating can be used for port switching, thereby facilitating the reduction of port insertion loss.

[0020] In some embodiments, the distance between the first port and the first portion at the orthographic projection position on the first reference line is greater than or equal to This design can improve the compactness of the port arrangement in the optical fiber array while avoiding the distance between the ports being too close, so as to improve the problems of increased processing difficulty, reduced control accuracy, high control precision requirements and increased crosstalk caused by the close distance between the ports.

[0021] In some embodiments, the first port is located on the second reference line;

[0022] Alternatively, the first portion and the second portion are both located on the second reference line;

[0023] Alternatively, the first port and the first portion are located on both sides of the second reference line, respectively.

[0024] In the wavelength selective switch provided in the embodiment of the present application, the optical fiber array can adopt a variety of different arrangements, with flexible design and strong adaptability; it can be applicable to a variety of different application scenarios.

[0025] In some embodiments, the first port and the first part are respectively located on both sides of the second reference line, and the first port and the second port in the first part are at equal distances relative to the second reference line. In the wavelength selective switch provided in the embodiment of the present application, the first port and the aligned first part and the second part in the optical fiber array are symmetrically arranged relative to the second reference line. Such a design can reduce the complexity of the port switching process, so that the port switching can be realized more quickly and accurately, which is conducive to improving the performance of the wavelength selective switch. Moreover, it can be realized by a one-dimensional diffraction grating in both the wave-adding scenario and the wave-dropping scenario, which is conducive to reducing the port insertion loss.

[0026] In some embodiments, the distances of the first port and the second port in the first portion relative to the second reference line are both equal to the port size. Or 0.5 times. This design makes it easy to reduce the deflection angle in the dispersion direction during port switching, thereby reducing the requirements for the diffraction deflection angle range of the spatial light modulator in the dispersion direction while ensuring the compactness of the port arrangement in the optical fiber array, which is beneficial to reducing port insertion loss and improving the performance of the wavelength selective switch.

[0027] In some embodiments, the first part and the second part have different orthographic projection positions on the first reference line; the first port is connected to the first part or the second part. With such a design, while achieving bilateral deflection and improving crosstalk problems, a one-dimensional diffraction grating can be used for port switching in some scenarios, which is beneficial to reducing port insertion loss.

[0028] In some embodiments, the first portion is located on the second reference line; or, the second portion is located on the second reference line; or, the first portion and the second portion are located on both sides of the second reference line, respectively.

[0029] In the wavelength selective switch provided in the embodiment of the present application, the optical fiber array can adopt a variety of different arrangements, with flexible design and strong adaptability, and can be applied to a variety of different application scenarios.

[0030] In some embodiments, the spacing between the first part and the second part at the orthographic projection position on the first reference line is equal to the port size. Such a design facilitates reducing the deflection angle in the dispersion direction during port switching, thereby reducing the requirements for the diffraction deflection angle range of the spatial light modulator in the dispersion direction while ensuring the compactness of the port arrangement in the optical fiber array, which is beneficial to reducing port insertion loss and improving the performance of the wavelength selective switch.

[0031] In some embodiments, the first port, the first part, and the second part have different orthographic projection positions on the first reference line. This design can further avoid the possibility of crosstalk-order diffracted light beams entering the optical fiber port, which helps to improve the isolation and directivity of the wavelength selective switch.

[0032] In some embodiments, the first port is located at the center of the optical path; the first portion and the second portion are located on the same side of the second reference line; or, the first portion and the second portion are located on both sides of the second reference line. In the wavelength selective switch provided in the embodiment of the present application, the optical fiber array can adopt a variety of different arrangements, with flexible design and strong adaptability, and can be applied to different application scenarios.

[0033] In some embodiments, the number of second ports in the first part and the second part is equal; in the port direction, the second ports in the first part and the second ports in the second part are arranged at the same spacing; the minimum distance between the second port in the first part and the first reference line is equal to the minimum distance between the second port in the second part and the first reference line. With such a design, the diffraction deflection angles on both sides of the spatial light modulator during bilateral deflection can be fully utilized, thereby facilitating the reduction of port insertion loss.

[0034] In some embodiments, the wavelength selective switch further comprises an intermediate optical component located between the optical fiber array and the spatial light modulator; the intermediate optical component is used to optically adjust the light beam transmitted between the optical fiber array and the spatial light modulator. Optically adjusting the light beam transmitted between the optical fiber array and the spatial light modulator through the optical component is beneficial to the accurate and efficient transmission of the light beam between the spatial light modulator and the optical fiber array on the one hand; and is beneficial to adjusting the optical path layout of the wavelength selective switch, thereby facilitating the reduction of the size of the wavelength selective switch.

[0035] In some embodiments, the spatial light modulator is liquid crystal on silicon, which has the characteristics of a flexible grid and supports flexible adjustment of the channel bandwidth of the wavelength selective switch.

[0036] In a second aspect, an embodiment of the present application provides a node device, which includes at least one wavelength selective switch as described in any one of the embodiments of the first aspect.

[0037] The technical effect that can be achieved by the node device provided in the embodiment of the present application is the same as the technical effect that can be achieved by the wavelength selective switch in any of the above embodiments, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic diagram of the structure of an optical network provided in an embodiment of the present application;

[0039] Figure 2A schematic diagram of the structure of a wavelength selective switch provided in an embodiment of the present application;

[0040] Figure 3 A front view of a silicon-based liquid crystal provided in an embodiment of the present application;

[0041] Figure 4 for Figure 3 Cross-sectional view of liquid crystal on silicon;

[0042] Figure 5 for Figure 3 Schematic diagram of the principle of liquid crystal on silicon forming a one-dimensional diffraction grating;

[0043] Figure 6 for Figure 3 Schematic diagram of the principle of liquid crystal on silicon forming a two-dimensional diffraction grating;

[0044] Figure 7 A schematic diagram of a dispersion spot and a pixel area provided in an embodiment of the present application;

[0045] Figure 8 A schematic diagram of the arrangement of an optical fiber array in a wavelength selective switch provided for related technologies;

[0046] Fig. 9 for Figure 8 The working principle diagram of the optical fiber array;

[0047] Fig.10 A schematic diagram of the arrangement of an optical fiber array in a wavelength selective switch provided in an embodiment of the present application;

[0048] Fig.11A A schematic diagram of a port plane optical path of a wavelength selective switch provided in an embodiment of the present application in a wave-drop scenario;

[0049] Fig. 11B A schematic diagram of a dispersion plane optical path of a wavelength selective switch in a wave-drop scenario provided by an embodiment of the present application;

[0050] Fig.12 A diagram showing the relationship between the positions of the diffracted light beam and the optical fiber array of the wavelength selective switch provided in an embodiment of the present application in a wave-down scenario;

[0051] Fig.13A A schematic diagram of a port plane optical path of a wavelength selective switch provided in an embodiment of the present application in a wavelength loading scenario;

[0052] Fig. 13B A schematic diagram of a dispersion plane optical path of a wavelength selective switch in a wave loading scenario provided by an embodiment of the present application;

[0053] Fig.14 A diagram showing the relationship between the positions of the diffracted light beam and the optical fiber array of the wavelength selective switch provided in an embodiment of the present application in a wave-adding scenario;

[0054] Fig.15 A schematic diagram of the arrangement of an optical fiber array in another wavelength selective switch provided in an embodiment of the present application;

[0055] Fig.16A A schematic diagram of a port plane optical path of a wavelength selective switch provided in an embodiment of the present application in a wave-drop scenario;

[0056] Fig. 16B A schematic diagram of a dispersion plane optical path of a wavelength selective switch in a wave-drop scenario provided by an embodiment of the present application;

[0057] Fig.17 A diagram showing the relationship between the positions of the diffracted light beam and the optical fiber array of the wavelength selective switch provided in an embodiment of the present application in a wave-down scenario;

[0058] Fig.18A A schematic diagram of a port plane optical path of a wavelength selective switch provided in an embodiment of the present application in a wavelength loading scenario;

[0059] Fig.18B A schematic diagram of a dispersion plane optical path of a wavelength selective switch in a wave loading scenario provided by an embodiment of the present application;

[0060] Fig.19 A diagram showing the relationship between the positions of the diffracted light beam and the optical fiber array of the wavelength selective switch provided in an embodiment of the present application in a wave-adding scenario;

[0061] Fig. 20 A schematic diagram of the arrangement of an optical fiber array in another wavelength selective switch provided in an embodiment of the present application;

[0062] Fig.21A A schematic diagram of a port plane optical path of a wavelength selective switch provided in an embodiment of the present application in a wave-drop scenario;

[0063] Fig. 21B A schematic diagram of a dispersion plane optical path of a wavelength selective switch in a wave-drop scenario provided by an embodiment of the present application;

[0064] Fig. 22 A diagram showing the relationship between the positions of the diffracted light beam and the optical fiber array of the wavelength selective switch provided in an embodiment of the present application in a wave-down scenario;

[0065] Fig.23A A schematic diagram of a port plane optical path of a wavelength selective switch provided in an embodiment of the present application in a wavelength loading scenario;

[0066] Fig. 23B A schematic diagram of a dispersion plane optical path of a wavelength selective switch in a wave loading scenario provided by an embodiment of the present application;

[0067] Fig.24A diagram showing the relationship between the positions of the diffracted light beam and the optical fiber array of the wavelength selective switch provided in an embodiment of the present application in a wave-adding scenario;

[0068] Fig.25 A schematic diagram of the arrangement of an optical fiber array in another wavelength selective switch provided in an embodiment of the present application;

[0069] Fig.26A A schematic diagram of a port plane optical path of a wavelength selective switch provided in an embodiment of the present application in a wave-drop scenario;

[0070] Fig.26B A schematic diagram of a dispersion plane optical path of a wavelength selective switch in a wave-drop scenario provided by an embodiment of the present application;

[0071] Fig. 27 A diagram showing the relationship between the positions of the diffracted light beam and the optical fiber array of the wavelength selective switch provided in an embodiment of the present application in a wave-down scenario;

[0072] Fig.28A A schematic diagram of a port plane optical path of a wavelength selective switch provided in an embodiment of the present application in a wavelength loading scenario;

[0073] Fig.28B A schematic diagram of a dispersion plane optical path of a wavelength selective switch in a wave loading scenario provided by an embodiment of the present application;

[0074] Fig.29 A diagram showing the position relationship between the diffracted light beam and the optical fiber array of the wavelength selective switch provided in an embodiment of the present application in a wave-adding scenario. DETAILED DESCRIPTION

[0075] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0076] In the following, in the embodiments of the present application, the terms "first", "second", etc. are only used for convenience of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, "plurality" means two or more.

[0077] In the embodiments of the present application, "up", "down", "left" and "right" are not limited to being defined relative to the orientation of the components schematically placed in the drawings. It should be understood that these directional terms may be relative concepts. They are used for relative description and clarification, and may change accordingly according to changes in the orientation of the components placed in the drawings.

[0078] In the embodiments of the present application, unless the context requires otherwise, throughout the specification and claims, the term "including" is interpreted as an open, inclusive meaning, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "exemplarily" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present application. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics described may be included in any one or more embodiments or examples in any appropriate manner.

[0079] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of variation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0080] As used herein, "parallel", "perpendicular", and "equal" include the situations described and situations similar to the situations described, and the range of the similar situations is within the acceptable deviation range, wherein the acceptable deviation range is determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism may be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity may also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality may be, for example, the difference between the two equalities is less than or equal to 5% of either one.

[0081] It will be understood that when a layer or an element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present between the layer or element and the other layer or substrate.

[0082] In the embodiments of the present application, exemplary embodiments are described with reference to cross-sectional views and / or plan views and / or equivalent circuit diagrams as idealized exemplary drawings. In the drawings, the thickness of the layers and regions is magnified for clarity. Therefore, it is conceivable that the shape changes relative to the drawings are caused by, for example, manufacturing technology and / or tolerances. Therefore, the exemplary embodiments should not be interpreted as being limited to the shapes of the regions shown herein, but include shape deviations caused by, for example, manufacturing. For example, an etched region shown as a rectangle will generally have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shapes of the regions of the device, and are not intended to limit the scope of the exemplary embodiments.

[0083] The present application embodiment provides a node device, which can be applied to Figure 1 The optical network 1000 can be applied to various communication scenarios, such as local telephone trunk lines, long-distance trunk communications, global communication networks, and public telecommunication networks of various countries. The optical network can also be used for the transmission of television signals, industrial production site monitoring and dispatching, traffic monitoring and control command, urban cable television networks, community antenna television systems (CATV), and optical fiber local area networks.

[0084] The optical network 1000 may include a plurality of node devices, which are interconnected through optical channels. One of the node devices may be connected to any number of other node devices 100. The node device 100 may be a reconfigurable optical add-drop multiplexer (ROADM) or an optical cross-connect (OXC). In some embodiments of the present application, the node device 100 may include a plurality of optical wavelength selective switches (WSS) to implement wavelength scheduling functions between different dimensions.

[0085] The embodiment of the present application also provides a wavelength selection switch, which can be applied to the node device 100 in the above embodiment. Figure 2 As shown, the wavelength selective switch 1 includes a silicon-based liquid crystal 4, an optical fiber array 2, and an intermediate optical component 3 arranged between the silicon-based liquid crystal 4 and the optical fiber array 2.

[0086] The silicon-based liquid crystal 4 is a reflective diffraction grating that can be programmed to achieve a specific phase distribution, and its main function is to deflect the incident light beam to the corresponding emission direction. Figure 3 The front view of a silicon-based liquid crystal 4 provided in the embodiment of the present application is as follows Figure 3 As shown, the silicon-based liquid crystal 4 includes a pixel array, and the pixel array includes a plurality of pixels (Pixel) 41 arranged in a plurality of rows and columns along a first direction and a second direction, and the first direction and the second direction are perpendicular to each other. Figure 3 Taking the orientation shown in as an example, the first direction is the horizontal direction, the second direction is the vertical direction, the row direction in the pixel array can be parallel to the first direction, and the column direction can be parallel to the second direction.

[0087] Figure 4 for Figure 3 A cross-sectional view of a silicon-based liquid crystal 4, such as Figure 4 As shown, the silicon-based liquid crystal 4 includes a silicon substrate 403, a transparent cover plate 401 and a liquid crystal layer 402. The silicon substrate 403 and the transparent cover plate 401 are arranged opposite to each other, and the liquid crystal layer 402 is arranged between the silicon substrate 403 and the transparent cover plate 401. The silicon substrate 403 has a reflective layer that can reflect the incident light beam, and is also provided with an array-arranged pixel circuit, wherein the pixel circuit includes a first electrode 405 corresponding to the pixel 41; and a second electrode 404 is provided on a side of the transparent cover plate 401 close to the silicon substrate 403.

[0088] In this case, by applying a voltage to the second electrode 404 and adjusting the voltage applied to different first electrodes 405 in the pixel circuit, the deflection angle of the liquid crystal molecules in the liquid crystal layer 402 corresponding to the position of the first electrode 405, that is, the deflection angle of the liquid crystal molecules in the pixel can be controlled. Due to the birefringence effect of the liquid crystal molecules, different voltages applied between the first electrode 405 and the second electrode 404 will correspond to different phase delays, thereby forming a structure similar to a blazed grating. Because the diffraction deflection angle of the blazed grating depends on the grating period of the blazed grating, it is only necessary to change the grating period corresponding to different positions on the silicon-based liquid crystal 4 to control the diffraction deflection angle of the incident light beam and achieve diffraction and deflection of the incident light beam.

[0089] In addition, since the port insertion loss in the wavelength selective switch 1 is positively correlated with the diffraction deflection angle of the silicon-based liquid crystal 4, that is, the larger the diffraction deflection angle, the larger the port insertion loss. Therefore, once the port insertion loss baseline is determined, the diffraction deflection angle range that the silicon-based liquid crystal 4 can support is also determined.

[0090] The silicon-based liquid crystal 4 may be a one-dimensional diffraction grating that forms a blazed grating only in the second direction, such as Figure 5 As shown, the grating direction of the blazed grating 5 formed in the second direction is parallel to the second direction, and the blazed grating 5 can diffract and deflect the incident light beam in the second direction; the one-dimensional diffraction grating can only reflect the incident light beam in the first direction, which is equivalent to the role of a reflecting mirror.

[0091] The silicon-based liquid crystal 4 can also be a two-dimensional diffraction grating that forms a blazed grating 5 in both the first direction and the second direction, such as Figure 6 As shown, the silicon-based liquid crystal 4 can form a first blazed grating and a second blazed grating in the first direction and the second direction respectively. The grating direction of the first blazed grating is parallel to the first direction, and the incident light beam can be diffracted and deflected in the first direction; the grating direction of the second blazed grating is parallel to the second direction, and the incident light beam can be diffracted and deflected in the second direction. Through the joint action of the first blazed grating and the second blazed grating, the incident light beam can be diffracted and deflected in any direction.

[0092] In the embodiment of the present application, whether the silicon-based liquid crystal 4 adopts a one-dimensional diffraction grating or a two-dimensional diffraction grating can be determined according to the arrangement of the optical fiber array 2 and the application scenario, and the details can be referred to the following description.

[0093] Please continue to refer to Figure 2 The wavelength selective switch 1 further comprises an optical fiber array 2, wherein the optical fiber array 2 comprises a plurality of optical fiber ports, wherein the plurality of optical fiber ports comprises a first port D0 and a plurality of second ports (D1 to D N ); wherein the first port D0 is a COM port, i.e. a public port; the second port is (D1 to D N ) is not a COM port. That is, the wavelength selective switch 1 provided in the embodiment of the present application adopts a 1×N architecture.

[0094] The first port and the second port in the optical fiber array 2 have different functions in different working scenarios of the wavelength selective switch 1. The working scenarios of the wavelength selective switch 1 can be divided into a wavelength adding scenario and a wavelength dropping scenario. In the wavelength dropping scenario, Figure 2 As shown by the solid arrow, the first port D0 is used to receive the incident light beam, and the wavelength selective switch 1 processes the incident light beam to form an outgoing light beam, which passes through the second port (D1 to D N ) output, that is, the target port for outputting the outgoing beam in the next wave scenario is a second port (D1 to D N ). In the previous scenario, Figure 2 As shown by the dashed arrow, the second port (D1 to D N ) is used to receive an incident light beam, and the wavelength selective switch 1 processes the incident light beam to form an outgoing light beam, and the outgoing light beam is output through the first port D0, that is, the target port for outputting the outgoing light beam in the wave loading scenario is the first port D0.

[0095] The first port D0 receives the incident beam in the down-wave scenario, and the second ports (D1 to D N) In the wave-up scenario, the incident light beams received can be optical signals of different wavelengths mixed together to form a multi-wavelength mixed signal, and the multi-wavelength mixed signal is transmitted in the same optical fiber port; thereby, wavelength division multiplexing (WDM) technology can be realized to achieve the purpose of high-speed data transmission.

[0096] In the case where the incident light beam is a multi-wavelength mixed signal, the multi-wavelength mixed signal is irradiated onto the silicon-based liquid crystal 4 through the intermediate optical component 3. Figure 7 As shown, the intermediate optical component 3 can spatially separate the optical signals of each wavelength in the multi-wavelength mixed signal, and project the optical signals of different wavelengths to different positions of the silicon-based liquid crystal 4, forming a plurality of dispersion light spots (λ1 to λ2) arranged along the same straight line on the silicon-based liquid crystal 4. M ). Multiple dispersion spots (λ1 to λ M ) can be arranged in a direction parallel to the first direction or the second direction. M ) is taken as an example that the direction of the arrangement straight line is parallel to the first direction. Those skilled in the art can adapt the solution to the situation where it is parallel to the second direction based on the description in this article.

[0097] Please continue to refer to Figure 7 The pixel array of the silicon-based liquid crystal 4 is divided into a plurality of pixel regions 42 according to the dispersion light spot. The plurality of pixel regions 42 have a corresponding relationship with the dispersion light spots of different wavelengths. One pixel region 42 corresponds to a dispersion light spot of a specific wavelength (λ1 to λ M The silicon-based liquid crystal 4 can control the pixels in the pixel area 42 to form a dispersion spot (λ1 to λ M ) of the blazed grating; the dispersion spot (λ1 to λ M After being diffracted and deflected by the blazed grating, the light beam passes through the intermediate optical component 3 to form an outgoing light beam that can be emitted through the target port.

[0098] Moreover, for the wavelength selective switch 1 using a 1×N architecture, since the dispersion spot projected onto the silicon-based liquid crystal 4 is only a row extending in the first direction, the multiple pixel regions 42 on the silicon-based liquid crystal 4 are also only a row arranged along the first direction. In this case, the length of the pixel region 42 in the first direction (dispersion direction) is much smaller than the length in the second direction, that is, the pixel region 42 is in the shape of a "slim strip". In combination with the above content, it can be seen that the diffraction deflection angle of the silicon-based liquid crystal 4 to the incident light beam is related to the grating period, and the adjustment of the grating period is related to the length of the pixel region 42 in the grating direction. Therefore, when the length of the pixel region 42 in the first direction is much smaller than the length in the second direction, the diffraction deflection angle range that the pixel region 42 can support for the dispersion spot in the first direction is much smaller than the diffraction deflection angle range that can be supported in the second direction.

[0099] Since the working principle of silicon-based liquid crystal 4 is based on the diffraction effect, when silicon-based liquid crystal 4 is used as an optical engine to load the blazed grating, diffraction beams of multiple diffraction orders are generated, such as -2 order, -1 order, 0 order, +1 order and +2 order, etc. The diffraction beams of each diffraction order are arranged on a straight line parallel to the grating direction of the blazed grating, and the diffraction beams of positive and negative orders are symmetrically distributed relative to the 0-order diffraction beam.

[0100] In the wavelength selective switch 1, the +1 order is selected as the target order, and all diffraction orders except the +1 order are crosstalk orders. During the operation of the wavelength selective switch 1, the +1 order diffraction beam is deflected to the target port for emission by controlling the blazed grating formed by the silicon-based liquid crystal 4; in this case, the diffraction beams of other diffraction orders, i.e., the crosstalk orders, may enter other optical fiber ports; when the diffraction beams of the crosstalk orders enter other optical fiber ports, crosstalk problems may occur between the optical fiber ports, affecting the isolation and directivity of the wavelength selective switch 1.

[0101] In order to improve the crosstalk problem caused by the diffracted light beams of the crosstalk order entering other optical fiber ports, a wavelength selective switch 1 is provided in the related art, such as Figure 8 As shown, the optical fiber array 2 in the wavelength selective switch 1 includes a plurality of optical fiber ports arranged along a straight line, and the plurality of optical fiber ports are respectively a first port D0 and a plurality of second ports (D1 to D N ), and a plurality of second ports (D1 to D N ) are arranged on one side of the first port D0. Please refer to Fig. 9 With such a design, when the incident light beam is received at the first port D0 and output at a second port (eg D2), all negative-order diffracted light beams can be prevented from entering the optical fiber ports, thereby improving the crosstalk problem between the optical fiber ports.

[0102] However, in the wavelength selection switch 1 provided by the related technology, in order to improve the crosstalk problem between the optical fiber ports, the silicon-based liquid crystal 4 is unilaterally deflected, and only the diffraction deflection angle on one side of the silicon-based liquid crystal 4 is utilized, which is half of the diffraction deflection angle range that the silicon-based liquid crystal 4 can support; therefore, it is not conducive to the expansion of the number of optical fiber ports in the optical fiber array 2; it is difficult to meet the requirements for the number of ports in large-port application scenarios.

[0103] Based on this, an embodiment of the present application provides a wavelength selective switch 1, in which the arrangement of the optical fiber array 2 in the wavelength selective switch 1 is improved to improve the problem that the crosstalk problem between ports affects the expansion of the number of ports.

[0104] In order to facilitate the description of the optical fiber array 2, the optical path center, dispersion direction, first reference line, port direction and second reference line are defined in this article. Fig.10 , wherein the optical path center O is the position where the input spot of the incident light beam in the optical fiber array 2 and the output spot of the reflected light beam reflected by the silicon-based liquid crystal 4 overlap when the silicon-based liquid crystal 4 does not generate a phase diagram, that is, when it is equivalent to a reflecting mirror.

[0105] Dispersion direction X: When the silicon-based liquid crystal 4 forms a blazed grating in the first direction, the spot centers of the diffracted light beams of each diffraction order are collinear, and the direction parallel to the straight line where the spot centers of the diffracted light beams of each diffraction order are located is the dispersion direction X. When the silicon-based liquid crystal 4 generates blazed gratings with different grating periods in the first direction, the spot center trajectory of the output +1-order diffracted light beam is also parallel to the dispersion direction X; that is, the dispersion direction X is the direction corresponding to the first direction in the silicon-based liquid crystal 4; that is, the direction corresponding to the arrangement direction of the dispersion spots of different wavelengths.

[0106] The first reference line L1: a straight line passing through the center O of the optical path and parallel to the dispersion direction X; from another perspective, when the first port D0 is located at the center O of the optical path and receives the incident light beam, and the silicon-based liquid crystal 4 generates a blazed grating with different grating periods in the first direction, the center trajectory of the light spot of the output +1-order diffraction light beam is the first reference line L1.

[0107] Port direction Y: When the silicon-based liquid crystal 4 forms a blazed grating in the second direction, the spot centers of the diffracted light beams of each diffraction order are collinear, and the direction parallel to the straight line where the spot centers of the diffracted light beams of each diffraction order are located is the port direction Y. When the silicon-based liquid crystal 4 generates blazed gratings with different grating periods in the second direction, the spot center trajectory of the output +1 order diffracted light beam is also parallel to the port direction Y; that is, the port direction Y is the direction corresponding to the second direction in the silicon-based liquid crystal 4; the port direction Y and the dispersion direction X are perpendicular to each other.

[0108] Second reference line L2: a straight line passing through the center O of the optical path and parallel to the port direction Y; from another perspective, the first port D0 is located at the center O of the optical path and receives the incident light beam; when the silicon-based liquid crystal 4 generates a blazed grating with different grating periods in the second direction, the center trajectory of the light spot of the output +1-order diffraction light beam is the second reference line L2; the first reference line L1 and the second reference line L2 are perpendicular to each other.

[0109] In the wavelength selective switch 1 provided in the embodiment of the present application, the optical fiber array 2 includes a plurality of optical fiber ports, and the plurality of optical fiber ports include a first port D0 and a plurality of second ports (D1 to D2). N ); wherein the first port D0 is located on the first reference line L1; a plurality of second ports (D1 to D N ) includes a first part 21 and a second part 22 respectively located on both sides of a first reference line L1; the second ports in the first part 21 are arranged along a direction parallel to the second reference line L2; the second ports in the second part 22 are arranged along a direction parallel to the second reference line L2.

[0110] Herein, the distances of the first port D0, the first portion 21, and the second portion 22 relative to the second reference line L2 are defined as the first distance, the second distance, and the third distance, respectively. In the optical fiber array 2 using the above design, at least one of the first distance, the second distance, and the third distance is not equal to 0; when the first distance is equal to 0, and the second distance and the third distance are both greater than 0, the first portion 21 and the second portion 22 are asymmetrically arranged relative to the first port D0.

[0111] That is to say, at least one of the first port D0, the first part 21 and the second part 22 is located on one side of the second reference line L2; when the first port D0 is located on the second reference line L2 and the first part 21 and the second part 22 are respectively located on both sides of the second reference line L2, the first part 21 and the second part 22 are asymmetrically arranged relative to the first port D0.

[0112] It should be noted that, in this article, the first part 21 and the second part 22 are arranged asymmetrically with respect to the first port D0, which means that the first part 21 and the second part 22 are arranged non-"point symmetrically" with respect to the first port D0. The first part 21 and the second part 22 are arranged "point symmetrically" with respect to the first port D0, which means that after the first part 21 and the second part 22 rotate 180 degrees around the first port D0, the new position coincides with the original position. The non-"point symmetrical" arrangement refers to an arrangement other than "point symmetrical".

[0113] Furthermore, in the optical fiber array 2 provided in the embodiment of the present application, the first distance, the second distance, and the third distance are all less than or equal to 2 times the port size, wherein the port size is the size of the optical fiber port, and the size of the size is related to the adapted optical fiber specification. Exemplarily, the size range of the port size can be 60 μm to 300 μm. N ) are circular ports of the same size. Therefore, the port size can be the size of the first port D0 in the dispersion direction X or the port direction Y, or the size of the second port (D1 to D N ) in the dispersion direction X or the port direction Y.

[0114] It should be noted that the optical fiber ports (first port D0 and second port (D1 to D N )) All the related distances are measured with the center of the optical fiber port as the reference. For example, the distance of the first port D0 relative to the second reference line L2 refers to the distance of the port center of the first port D0 relative to the second reference line L2, and the distance of the first portion 21 relative to the second reference line L2 refers to the distance of the port center of the second port in the first portion 21 relative to the second reference line L2.

[0115] It can be seen from the above description that in the optical fiber array 2 provided in the embodiment of the present application, the plurality of second ports (D1 to D N ) includes a first part 21 and a second part 22 disposed on both sides of a first reference line L1, at least one of the first part 21, the second part 22 and the first port D0 is located on one side of the second reference line L2, and the three are arranged asymmetrically relative to the optical path center O, that is, an offset, asymmetric arrangement is adopted.

[0116] With such a design, on the one hand, by adopting a design in which the second ports are arranged on both sides of the first reference line L1, the bilateral deflection of the silicon-based liquid crystal 4 can be used to switch the ports, so that more optical fiber ports can be supported when the diffraction deflection angle range supported by the silicon-based liquid crystal 4 is the same, and the application scenarios of large ports, such as 64D, 128D, etc., can be met. Or, when the number of optical fiber ports is the same, it is beneficial to reduce the port insertion loss.

[0117] On the other hand, the optical fiber array 2 adopts an offset, asymmetric arrangement, which helps to improve the situation where the diffracted light beams of the crosstalk order enter the optical fiber port, thereby improving the problem of crosstalk between optical fiber ports, which is beneficial to improving the isolation and directivity of the wavelength selective switch 1.

[0118] On the other hand, by limiting the first distance, the second distance and the third distance to be less than or equal to 2 times the port size, the distribution range of the first port D0, the first part 21 and the second part 22 in the dispersion direction X is limited.

[0119] According to the above description of the silicon-based liquid crystal 4 and the pixel area 42, the diffraction deflection angle range that the pixel area 42 can support in the first direction is much smaller than the diffraction deflection angle range that can be supported in the second direction. Therefore, in the wavelength selective switch 1 provided in the embodiment of the present application, by limiting the first distance, the second distance and the third distance to be less than or equal to 2 times the port size, the diffraction deflection angle of the silicon-based liquid crystal 4 in the dispersion direction X can be limited; thereby, while ensuring the compactness of the port arrangement in the optical fiber array 2, the requirements for the diffraction deflection angle range of the silicon-based liquid crystal 4 in the dispersion direction X can be reduced, which is conducive to reducing the port insertion loss and improving the performance of the wavelength selective switch 1.

[0120] The following will exemplarily illustrate different arrangements of the optical fiber array 2 in conjunction with the accompanying drawings, and explain the advantages and principles that the optical fiber array 2 can bring in conjunction with the wavelength selective switch 1 using the optical fiber array 2.

[0121] Please refer to Fig.10 , in order to facilitate the description of the first port D0 and the second port (D1 to D N ) and set the port size to p. A coordinate system is established with the optical path center O as the origin, the first reference line L1 as the X-axis, and the second reference line L2 as the Y-axis; the X-axis is negative to the right and positive to the left, and the Y-axis is positive upward and negative downward.

[0122] In order to facilitate understanding of the diffraction and deflection of the incident light beam by the silicon-based liquid crystal 4, in the following description of the working principle of the wavelength selective switch 1 in the wave-down scenario and the wave-down scenario, the incident light beam only includes an optical signal of one wavelength. And it will be explained from two aspects: the port plane optical path and the dispersion plane optical path. Among them, the port plane optical path refers to the optical path used by the wavelength selective switch 1 to control the deflection of the incident light beam in the port direction Y of the optical fiber array 2; the dispersion plane optical path refers to the optical path used by the wavelength selective switch 1 to control the deflection of the incident light beam in the dispersion direction X of the optical fiber array 2.

[0123] It should be noted that, since some devices or apparatuses of the wavelength selective switch 1 play a role in controlling the deflection of the incident light beam in the port direction Y of the optical fiber array 2, but do not play a role in controlling the deflection of the incident light beam in the dispersion direction X of the optical fiber array 2; some devices or apparatuses do not play a role in controlling the deflection of the incident light beam in the port direction Y of the optical fiber array 2, but play a role in controlling the deflection of the incident light beam in the dispersion direction X of the optical fiber array 2. In order to better understand the principle of light beam deflection, some ineffective devices or apparatuses are omitted in the port plane optical path and the dispersion plane optical path of the wavelength selective switch 1 provided in the embodiment of the present application.

[0124] The present application embodiment provides a wavelength selective switch 1, such as Fig.10 As shown, in the optical fiber array 2 of the wavelength selective switch 1, all optical fiber ports, namely the first port D0, the first part 21 and the second part 22 are located on the same side of the second reference line L2, for example, they are all located on the side corresponding to the negative direction of the X-coordinate axis, and for example, they are all located on the side corresponding to the positive direction of the X-coordinate axis. The first port D0, the first part 21 and the second part 22 are aligned in the dispersion direction X. It should be noted that in this article, alignment in the dispersion direction X means that the orthographic projection positions on the first reference line L1 are the same, that is, the X coordinates are the same; for example, the alignment of the first port D0, the first part 21 and the second part 22 in the dispersion direction X means that the orthographic projection positions of the first port D0, the first part 21 and the second part 22 on the first reference line L1 are the same; the X coordinates of the three are the same. When the orthographic projection positions on the first reference line L1 are different, it can be considered that they are staggered in the dispersion direction X.

[0125] When the first port D0, the first portion 21 and the second portion 22 are all located on the same side of the second reference line L2 and aligned in the dispersion direction X, the first distance, the second distance and the third distance are all greater than 0 and are equal. In addition, the first distance, the second distance and the third distance are all less than or equal to 2 times the port size.

[0126] For example, Fig.10 As shown, the first port D0, the first portion 21 and the second portion 22 are offset by 0.5p in the negative direction of the X-coordinate axis relative to the second reference line L2 (Y-coordinate axis). In this case, the X-coordinate of the first port D0 is -0.5p and the Y-coordinate is 0; all the second ports (D1 to D N ) are all -0.5p. The first distance, the second distance, and the third distance are all 0.5p.

[0127] The working principle of the wavelength selective switch 1 using the above optical fiber array 2 in the wavelength drop scenario is:

[0128] In the wavelet scene, the first port D0 is an incident port for receiving an incident light beam, and any second port is a target port for outputting an outgoing light beam. After the incident light beam is incident from the first port D0, it passes through the intermediate optical component 3 and irradiates the target pixel area on the silicon-based liquid crystal 4. Here, the target pixel area is a pixel area 42 corresponding to the optical signal of the wavelength among the multiple pixel areas 42 in the silicon-based liquid crystal 4.

[0129] Fig.11A A schematic diagram of the plane optical path of the port of the wavelength selective switch provided in the embodiment of the present application in the wave-down scenario, Fig.12 The relationship diagram of the position of the diffracted light beam and the optical fiber array in the wavelength selective switch provided in the embodiment of the present application in the wave-down scenario; Fig.11A and Fig.12 As shown, the silicon-based liquid crystal 4 controls the target pixel area to form a blazed grating in the second direction, and the blazed grating can diffract and deflect the incident light beam in the second direction (corresponding to the port direction Y), and will generate multiple diffraction order diffraction light beams arranged in the second direction, such as -2 order, -1 order, 0 order, +1 order and +2 order, etc. Among them, +1 order is the target order, and other diffraction orders except +1 order are crosstalk orders. At the same time, the blazed grating formed by the silicon-based liquid crystal 4 deflects the +1 order (target order) diffraction light beam in the port plane (the deflection angle is θ y ), the deflected +1st order diffraction beam passes through the intermediate optical component 3 and irradiates the optical fiber array 2. The Y coordinate Y of the exit position of the +1st order diffraction beam in the optical fiber array 2 is +1 The Y coordinate Y of the target port (a second port) t Same, that is, Y +1 =Y t .

[0130] Please continue to refer to Fig.11A and Fig.12 The blazed grating formed by the silicon-based liquid crystal 4 will also deflect the crosstalk-order diffracted light beam in the port plane; wherein the Y coordinate Y0 of the 0th order diffracted light beam at the exit position in the optical fiber array 2 is the same as the Y coordinate Y of the first port D0. com Same, that is, Y0=Y com , the Y coordinate Y of the -1st order diffraction beam at the exit position in the optical fiber array 2 -1 The Y coordinate of the second port c The same; and Y +1 and Y -1 Symmetrical about the X coordinate axis, that is, Y t =-Y c .

[0131] If the silicon-based liquid crystal 4 adopts a one-dimensional diffraction grating that can only form a blazed grating in the second direction, it is equivalent to a reflecting mirror in the first direction, thereby reflecting the diffracted light beam formed by the blazed grating in the second direction in the dispersion plane. The X coordinate of the diffracted light beam of each diffraction order is +0.5p, so it cannot reach the target port (X coordinate is -0.5p) for emission.

[0132] Based on this, in the present embodiment, the LCOS 4 adopts a two-dimensional diffraction grating that can form a blazed grating in both the first direction and the second direction.

[0133] Fig. 11B A schematic diagram of a dispersion plane optical path of a wavelength selective switch provided in an embodiment of the present application in a wavelet drop scenario, such as Fig. 11B and Fig.12As shown, the silicon-based liquid crystal 4 controls the target pixel area to also form a blazed grating in the first direction, and the blazed grating can diffract and deflect the incident light beam in the first direction (corresponding to the dispersion direction X), and will generate multiple diffraction order diffraction light beams arranged in the first direction, such as -2 order, -1 order, 0 order, +1 order and +2 order, etc. Among them, +1 order is the target order, and other diffraction orders except +1 order are crosstalk orders. At the same time, the blazed grating formed by the silicon-based liquid crystal 4 deflects the +1 order (target order) diffraction light beam in the dispersion plane (the deflection angle is θ x ), the deflected +1st order diffraction beam passes through the intermediate optical component 3 and irradiates the optical fiber array 2. The X coordinate X of the exit position of the +1st order diffraction beam in the optical fiber array 2 is +1 The X coordinate of the target port (a second port) t Same; that is, X +1 =X t =-0.5p.

[0134] Please continue to refer to Fig. 11B and Fig.12 The blazed grating formed by the silicon-based liquid crystal 4 will also deflect the diffracted light beams of the crosstalk order in the dispersion plane; in this embodiment, the diffracted light beams of the crosstalk order are all projected to the position outside the port in the optical fiber array 2. For example, Fig.12 As shown, the X coordinate X0 of the position where the 0th order diffraction beam is emitted from the optical fiber array 2 is +0.5p; the X coordinate X of the position where the -1st order diffraction beam is emitted from the optical fiber array 2 is -1 is +1.5p; the X coordinate X of the exit position of the +2nd order diffraction beam in the optical fiber array 2 +2 It is -1.5p.

[0135] It can be seen from this that in the wavelength selective switch 1 provided in this embodiment, only the diffracted light beam of the target order (+1 order) can be emitted through the target port in the wave drop scenario, and the diffracted light beam of the crosstalk order cannot enter the optical fiber port in the optical fiber array 2, thereby improving the port isolation and reducing the signal crosstalk between ports.

[0136] The working principle of the wavelength selective switch 1 using the above optical fiber array 2 in the wavelength adding scenario is:

[0137] In the wave loading scenario, any second port is used as an incident port for receiving an incident light beam, and the second port can be called a source port; the first port D0 is a target port for outputting an outgoing light beam.

[0138] Fig.13A A schematic diagram of a port plane optical path of a wavelength selective switch provided in an embodiment of the present application in a wavelength loading scenario, Fig.14The relationship diagram of the position of the diffracted light beam and the optical fiber array in the wavelength selective switch provided in the embodiment of the present application in the wave-up scenario; Fig.13A and Fig.14 As shown, the silicon-based liquid crystal 4 controls the target pixel area to form a blazed grating in the second direction, and the blazed grating can diffract and deflect the incident light beam in the second direction (corresponding to the port direction Y), and will generate multiple diffraction order diffraction light beams arranged in the second direction, such as -2 order, -1 order, 0 order, +1 order and +2 order, etc. Among them, +1 order is the target order, and other diffraction orders except +1 order are crosstalk orders. At the same time, the blazed grating formed by the silicon-based liquid crystal 4 deflects the +1 order diffraction light beam in the port plane (the deflection angle is θ y ), the deflected +1st order diffraction beam passes through the intermediate optical component 3 and irradiates the optical fiber array 2. The Y coordinate Y of the exit position of the +1st order diffraction beam in the optical fiber array 2 is +1 The Y coordinate Y of the target port (first port D0) com Same, that is, Y +1 =Y com .

[0139] Please continue to refer to Fig.13A and Fig.14 The blazed grating formed by the silicon-based liquid crystal 4 will also deflect the crosstalk-order diffracted light beam in the port plane; wherein the Y coordinate Y0 of the 0th order diffracted light beam at the exit position in the optical fiber array 2 is the same as the Y coordinate Y of a second port. c Same, and Y0=-Y c ; -Y coordinate Y of the exit position of the first-order diffracted beam in the optical fiber array 2 -1 Same as the Y coordinate of the other second port, or outside the port.

[0140] If the silicon-based liquid crystal 4 adopts a one-dimensional diffraction grating that can only form a blazed grating in the second direction, it is equivalent to a reflecting mirror in the first direction, thereby reflecting the diffracted light beam formed by the blazed grating in the second direction in the dispersion plane. The X coordinate of the diffracted light beam of each diffraction order is +0.5p, so it cannot reach the target port (X coordinate is -0.5p) for emission.

[0141] Based on this, in the present embodiment, the LCOS 4 adopts a two-dimensional diffraction grating that can form a blazed grating in both the first direction and the second direction. Fig. 13B A schematic diagram of a dispersion plane optical path of a wavelength selective switch in a wave loading scenario provided in an embodiment of the present application, such as Fig. 13B and Fig.14As shown, the silicon-based liquid crystal 4 also forms a blazed grating in the first direction by controlling the pixel area 42. The blazed grating can diffract and deflect the incident light beam in the first direction (corresponding to the dispersion direction X), and will generate a plurality of diffraction order diffraction light beams arranged in the first direction, such as -2 order, -1 order, 0 order, +1 order and +2 order, etc. Among them, +1 order is the target order, and other diffraction orders except +1 order are crosstalk orders. At the same time, the blazed grating formed by the silicon-based liquid crystal 4 deflects the +1 order diffraction light beam in the dispersion plane (the deflection angle is θ x ), the deflected +1st order diffraction beam passes through the intermediate optical component 3 and irradiates the optical fiber array 2. The X coordinate X of the exit position of the +1st order diffraction beam in the optical fiber array 2 is +1 The X coordinate X of the target port (second port) com Same; X +1 =X com =-0.5p.

[0142] Please continue to refer to Fig. 13B and Fig.14 The blazed grating formed by the silicon-based liquid crystal 4 will also deflect the diffracted light beams of the crosstalk order in the dispersion plane; in this embodiment, the diffracted light beams of the crosstalk order are all projected at the position outside the port, for example, the X coordinate X0 of the 0th order diffracted light beam at the exit position in the optical fiber array 2 is +0.5p; the X coordinate X0 of the -1st order diffracted light beam at the exit position in the optical fiber array 2 is -1 is +1.5p; the X coordinate X of the exit position of the +2nd order diffraction beam in the optical fiber array 2 +2 It is -1.5p.

[0143] It can be seen from this that in the wavelength selective switch 1 provided in this embodiment, in the wave adding scenario, only the diffracted light beam of the target order (+1 order) can be emitted through the target port, and the diffracted light beam of the crosstalk order cannot enter the optical fiber port in the optical fiber array 2, thereby achieving an improvement in port isolation and reducing signal crosstalk between ports.

[0144] Based on the above content, it can be seen that in the wavelength selective switch 1 provided in this embodiment, the optical fiber array 2 includes a first port D0 and a plurality of second ports (D1 to D N ), the plurality of second ports include a first portion 21 and a second portion 22 located on both sides of the first reference line L1. The first portion 21, the second portion 22 and the first port D0 are arranged in a "biased, asymmetric" manner, are located on the same side of the second reference line L2, and are aligned in the dispersion direction X. The silicon-based liquid crystal 4 adopts a bilateral deflection and two-dimensional grating working mode in both the up-wave scenario and the down-wave scenario.

[0145] With such a design, on the one hand, the bilateral deflection adopted by the silicon-based liquid crystal 4 can reduce the diffraction deflection angle required by the silicon-based liquid crystal 4, and for the same number of ports, the port insertion loss can be reduced, or for the same port insertion loss, the number of ports can be doubled. On the other hand, the optical fiber array 2 adopts a "biased, asymmetric" arrangement, and combined with the two-dimensional deflection realized by the two-dimensional grating of the silicon-based liquid crystal 4, it can effectively avoid the diffraction beams of non-+1 crosstalk order from entering the ports in the optical fiber array 2 to generate signal crosstalk, and effectively suppress the signal crosstalk between ports, which is beneficial to improve the isolation of the down-wave scene and the directionality of the up-wave scene.

[0146] In addition, by setting the first distance, the second distance and the third distance to be equal to 0.5p, the compactness of the port arrangement in the optical fiber array 2 can be ensured while reducing the requirements for the diffraction deflection angle range of the silicon-based liquid crystal 4 in the dispersion direction X, which is beneficial to reducing the port insertion loss and improving the performance of the wavelength selection switch 1.

[0147] In the above embodiment, the first distance, the second distance and the third distance are all 0.5p, but the optical fiber array 2 designed with the first port D0, the first part 21 and the second part 22 aligned in the dispersion direction X, and both located on one side of the second reference line L2 is not limited to this, and the first distance, the second distance and the third distance can be any value less than or equal to 2p, for example, 0.2p, 0.4p, 0.6p, 0.8, 1p, 1.2p, 1.4p, 1.6p, 1.8p, 2p.

[0148] From the above description of the working principle, it can be seen that the smaller the first distance, the second distance and the third distance are, the lower the requirement for the diffraction deflection angle of the silicon-based liquid crystal 4 in the dispersion direction X is. Therefore, under the condition of meeting other requirements, the smaller first distance, second distance and third distance should be selected as much as possible, so as to reduce the port insertion loss and improve the diffraction efficiency.

[0149] The present application embodiment provides another wavelength selective switch 1, such as Fig.15 As shown, in the optical fiber array 2 of the wavelength selective switch 1, the first port D0 is located at the intersection of the second reference line L2 and the first reference line L1, that is, the optical path center O; the first part 21 and the second part 22 are both located on the same side of the second reference line L2, for example, both are located on the side corresponding to the negative direction of the X-coordinate axis, and for example, both are located on the side corresponding to the positive direction of the X-coordinate axis. In addition, the first part 21 and the second part 22 are aligned in the dispersion direction X. In this case, the first distance is equal to 0, and the second distance and the third distance are both greater than 0 and equal. In addition, the first distance, the second distance, and the third distance are all less than or equal to 2 times the port size.

[0150] For example, Fig.15As shown, the first port D0 is located at the center O of the optical path, and the first portion 21 and the second portion 22 are offset as a whole toward the negative direction of the X-coordinate axis. In this case, the X coordinate of the first port D0 is 0, and the Y coordinate is 0; all the second ports (D1 to D N ) are both The distance between the first port D0 and the orthographic projection position of the first portion 21 on the first reference line L1 is The first distance is 0, the second distance and the third distance are

[0151] It should be noted that It is the minimum distance between one fiber port and the straight line where the other two fiber ports are located when three circular fiber ports of the same size are arranged in an equilateral triangle.

[0152] The working principle of the wavelength selective switch 1 using the above optical fiber array 2 in the wavelength drop scenario is:

[0153] In the down-wave scenario, the first port D0 is an incident port for receiving an incident light beam, and any second port is a target port for outputting an outgoing light beam.

[0154] Fig.16A A schematic diagram of the plane optical path of the port of the wavelength selective switch provided in the embodiment of the present application in the wave-down scenario, Fig.17 The relationship diagram of the position of the diffracted light beam and the optical fiber array in the wavelength selective switch provided in the embodiment of the present application in the wave-down scenario; Fig.16A and Fig.17 As shown, after the incident light beam is incident from the first port D0, it passes through the intermediate optical component 3 and irradiates the target pixel area on the silicon-based liquid crystal 4. The silicon-based liquid crystal 4 controls the target pixel area to form a blazed grating in the second direction, and the blazed grating can diffract and deflect the incident light beam, and deflect the +1 order (target order) diffracted light beam in the port plane (the deflection angle is θ y ), the deflected +1st order diffraction beam passes through the intermediate optical component 3 and irradiates the optical fiber array 2. The Y coordinate Y of the exit position of the +1st order diffraction beam in the optical fiber array 2 is +1 The Y coordinate Y of the target port (a second port) t Same, that is, Y +1 =Y t .

[0155] The blazed grating formed by the silicon-based liquid crystal 4 will also deflect the crosstalk order diffracted light beam in the port plane; wherein the Y coordinate Y0 of the 0th order diffracted light beam at the exit position in the optical fiber array 2 is the same as the Y coordinate Y of the first port D0. com Same, that is, Y0=Y com, the Y coordinate Y of the -1st order diffraction beam at the exit position in the optical fiber array 2 -1 The Y coordinate of the second port c The same; and Y +1 and Y -1 Symmetrical about the X coordinate axis, that is, Y t =-Y c .

[0156] If the silicon-based liquid crystal 4 uses a one-dimensional diffraction grating that can only form a blazed grating in the second direction, it is equivalent to a reflective mirror in the first direction, so that the diffracted light beam formed by the blazed grating in the second direction is reflected in the dispersion plane, and the X coordinates of the diffracted light beams of each diffraction order are all 0, so they cannot reach the target port (X coordinate is ) emission.

[0157] Based on this, in the present embodiment, the LCOS 4 adopts a two-dimensional diffraction grating that can form a blazed grating in both the first direction and the second direction.

[0158] Fig. 16B A schematic diagram of a dispersion plane optical path of a wavelength selective switch provided in an embodiment of the present application in a wavelet drop scenario, such as Fig. 16B and Fig.17 As shown, the silicon-based liquid crystal 4 controls the target pixel area to also form a blazed grating in the first direction, and the blazed grating can diffract and deflect the incident light beam, and deflect the +1 order (target order) diffracted light beam in the dispersion plane (the deflection angle is θ x ), the deflected +1st order diffraction beam is irradiated onto the optical fiber array 2 through the intermediate optical component 3, and the X coordinate X of the exit position of the +1st order diffraction beam in the optical fiber array 2 is +1 The X coordinate of the target port (a second port) t the same; that is

[0159] The blazed grating formed by the silicon-based liquid crystal 4 will also deflect the crosstalk order diffracted light beam in the dispersion plane; wherein the X coordinate X0 of the 0th order diffracted light beam at the exit position in the optical fiber array 2 is the same as the X coordinate X0 of the first port D0. com Same, X0=X com = 0; the exit positions of the diffracted beams of other crosstalk orders in the optical fiber array 2 are all located outside the port. For example, the exit position X coordinate of the -1 order diffracted beam in the optical fiber array 2 is -1 for Located outside the port.

[0160] It can be seen from this that in the wavelength selective switch 1 provided in this embodiment, only the diffracted light beam of the target order (+1 order) can be emitted through the target port in the wave drop scenario, and the diffracted light beam of the crosstalk order cannot enter the optical fiber port in the optical fiber array 2, thereby improving the port isolation and reducing the signal crosstalk between ports.

[0161] The working principle of the wavelength selective switch 1 using the above optical fiber array 2 in the wavelength adding scenario is:

[0162] In the wave loading scenario, any second port is used as an incident port for receiving an incident light beam, and the second port can be called a source port; the first port D0 is a target port for outputting an outgoing light beam.

[0163] Fig.18A A schematic diagram of a port plane optical path of a wavelength selective switch provided in an embodiment of the present application in a wavelength loading scenario; Fig.19 The relationship diagram of the position of the diffracted light beam and the optical fiber array in the wavelength selective switch provided in the embodiment of the present application in the wave-up scenario; Fig.18A and Fig.19 As shown, after the incident light beam is incident from the source port, it passes through the intermediate optical component 3 and irradiates the target pixel area on the silicon-based liquid crystal 4. The silicon-based liquid crystal 4 controls the target pixel area to form a blazed grating in the second direction, and the blazed grating can diffract and deflect the incident light beam, and deflect the +1 order (target order) diffracted light beam in the port plane (the deflection angle is θ y ), the deflected +1st order diffraction beam passes through the intermediate optical component 3 and irradiates the optical fiber array 2. The Y coordinate Y of the exit position of the +1st order diffraction beam in the optical fiber array 2 is +1 The Y coordinate Y of the target port (first port D0) com Same, that is, Y +1 =Y com .

[0164] The blazed grating formed by the silicon-based liquid crystal 4 will also deflect the crosstalk order diffracted light beam in the port plane; wherein the Y coordinate Y0 of the 0th order diffracted light beam at the exit position in the optical fiber array 2 is the same as the Y coordinate Y of a second port. c Same, and Y0=-Y c ; -Y coordinate Y of the exit position of the first-order diffracted beam in the optical fiber array 2 -1 Same as the Y coordinate of the other second port, or outside the port.

[0165] If the silicon-based liquid crystal 4 uses a one-dimensional diffraction grating that can only form a blazed grating in the second direction, it is equivalent to a reflective mirror in the first direction, so that the diffracted light beam formed by the blazed grating in the second direction is reflected in the dispersion plane, and the X coordinates of the diffracted light beams of each diffraction order are Therefore, it cannot reach the target port (X coordinate is 0).

[0166] Based on this, in the present embodiment, the LCOS 4 adopts a two-dimensional diffraction grating that can form a blazed grating in both the first direction and the second direction.

[0167] Fig.18B A schematic diagram of a dispersion plane optical path of a wavelength selective switch in a wave loading scenario provided in an embodiment of the present application, such as Fig.18B and Fig.19 As shown, the silicon-based liquid crystal 4 controls the target pixel area to also form a blazed grating in the first direction, and the blazed grating can diffract and deflect the incident light beam, and deflect the +1 order (target order) diffracted light beam in the dispersion plane (the deflection angle is θ x ), the deflected +1st order diffraction beam is irradiated onto the optical fiber array 2 through the intermediate optical component 3, and the X coordinate X of the exit position of the +1st order diffraction beam in the optical fiber array 2 is +1 The X coordinate X of the target port (second port) com Same; X +1 =X com =0.

[0168] The blazed grating formed by the silicon-based liquid crystal 4 will also deflect the diffracted light beams of the crosstalk order in the dispersion plane. In this embodiment, the diffracted light beams of the crosstalk order are all projected at the position outside the port in the optical fiber array 2. For example, the X coordinate X0 of the exit position of the 0th order diffracted light beam in the optical fiber array 2 is -X coordinate X of the position where the first-order diffracted beam emerges from the optical fiber array 2 -1 for

[0169] It can be seen from this that in the wavelength selective switch 1 provided in this embodiment, in the wave adding scenario, only the diffracted light beam of the target order (+1 order) can be emitted through the target port, and the diffracted light beam of the crosstalk order cannot enter the optical fiber port in the optical fiber array 2, thereby improving the port isolation and reducing the signal crosstalk between ports.

[0170] Based on the above content, it can be known that in the wavelength selective switch 1 provided in this embodiment, the optical fiber array 2 includes a first port D0 and multiple second ports, and the multiple second ports include a first part 21 and a second part 22 located on both sides of the first reference line L1. The first part 21, the second part 22 and the first port D0 are arranged in a "biased, asymmetric" manner, the first port D0 is located at the center of the optical path O, the first part 21 and the second part 22 are located on the same side of the second reference line L2, and are aligned in the dispersion direction X. The silicon-based liquid crystal 4 adopts the working mode of bilateral deflection and two-dimensional grating in both the upper wave scene and the lower wave scene.

[0171] With such a design, on the one hand, the bilateral deflection adopted by the silicon-based liquid crystal 4 can reduce the diffraction deflection angle required by the silicon-based liquid crystal 4, and for the same number of ports, the port insertion loss can be reduced, or for the same port insertion loss, the number of ports can be doubled. On the other hand, the optical fiber array 2 adopts a "biased, asymmetric" arrangement, and combined with the two-dimensional deflection realized by the two-dimensional grating of the silicon-based liquid crystal 4, it can effectively avoid the diffraction beams of non-+1 crosstalk order from entering the ports in the optical fiber array 2 to generate signal crosstalk, and effectively suppress the signal crosstalk between ports, which is beneficial to improve the isolation of the down-wave scene and the directionality of the up-wave scene.

[0172] In addition, by setting the first distance to 0, the second and third distances are both set to While ensuring the compactness of the port arrangement in the optical fiber array 2 , the requirement on the diffraction deflection angle range of the silicon-based liquid crystal 4 in the dispersion direction X can be reduced, which is beneficial to reducing the port insertion loss and improving the performance of the wavelength selective switch 1 .

[0173] In the above embodiment, the first distance is 0, and the second distance and the third distance are both However, the optical fiber array 2 designed in which the first port D0 is located at the optical path center O; the first portion 21 and the second portion 22 are located on the same side of the second reference line L2, and the first portion 21 and the second portion 22 are aligned in the dispersion direction X is not limited thereto, and the spacing between the orthographic projection positions of the first port D0 and the first portion 21 on the first reference line L1 is greater than or equal to For example, the first distance is 0, the second distance and the third distance are equal, and the second distance and the third distance are greater than or equal to And any value less than or equal to 2p, such as 1p, 1.2p, 1.4p, 1.6p, 1.8p, 2p.

[0174] From the above description of the working principle, it can be seen that the smaller the second distance and the third distance are, the lower the requirement for the diffraction deflection angle of the silicon-based liquid crystal 4 in the dispersion direction X is. Therefore, under the condition of meeting other requirements, the smaller second distance and third distance should be selected as much as possible, so as to reduce the port insertion loss and improve the diffraction efficiency.

[0175] The present application embodiment provides another wavelength selective switch 1, such as Fig. 20As shown, in the optical fiber array 2 of the wavelength selective switch 1, the first part 21 is located on one side of the second reference line L2, for example, on the side corresponding to the negative direction of the X-coordinate axis, and for example, on the side corresponding to the positive direction of the X-coordinate axis. The first port D0 and the second part 22 are both located on the second reference line L2, that is, the first port D0 is located at the optical path center O, the first port D0 and the second part 22 are aligned in the dispersion direction X, and the first port D0 and the first part 21 are staggered in the dispersion direction X. It can be seen that the X coordinates of the first port D0 and the second part 22 are the same, and the X coordinates of the first port D0 and the first part 21 are different. In this case, the first distance and the third distance are both equal to 0, and the second distance is greater than 0. In addition, the first distance, the second distance and the third distance are all less than or equal to 2 times the port size.

[0176] For example, Fig. 20 As shown, the first port D0 is located at the center O of the optical path, the second part 22 is located on the second reference line L2, and the first part 21 is offset p in the negative direction of the X coordinate axis relative to the second reference line L2. In this case, the X coordinates of the second ports in the first part 21 are all -p; the X coordinate of the first port D0 is 0, and the Y coordinate is 0; the X coordinates of the second ports in the second part 22 are all 0. The distance between the positive projection positions of the first port D0 and the first part 21 on the first reference line L1 is p; the first distance is 0, the second distance is p, and the third distance is 0.

[0177] The working principle of the wavelength selective switch 1 using the above optical fiber array 2 in the wavelength drop scenario is:

[0178] In the down-wave scenario, the first port D0 is an incident port for receiving an incident light beam, and any second port is a target port for outputting an outgoing light beam. Fig.21A A schematic diagram of a port plane optical path of a wavelength selective switch provided in an embodiment of the present application in a wave-drop scenario; Fig. 21B A schematic diagram of the dispersion plane optical path of the wavelength selective switch provided in the embodiment of the present application in the wavelet drop scenario, Fig. 22 A diagram showing the relationship between the position of the diffracted light beam and the optical fiber array in the wavelength selective switch provided in the embodiment of the present application in the wave-drop scenario; wherein: Fig.21A Part (a) of Fig. 21B Part (a) and Fig. 22 Part (a) in FIG. 2 is the case where the target port is the second port in the first part 21. Fig.21A Part (b) of Fig. 21B Part (b) and Fig. 22 Part (b) in FIG. 2 is a case where the target port is the second port in the second part 22 .

[0179] like Fig.21A and Fig. 22As shown, after the incident light beam is incident from the first port D0 , it passes through the intermediate optical component 3 and then irradiates the target pixel area on the silicon-based liquid crystal 4 .

[0180] The silicon-based liquid crystal 4 forms a blazed grating in the second direction by controlling the target pixel area. The blazed grating can diffract and deflect the incident light beam, deflecting the +1 order (target order) diffracted light beam in the port plane (the deflection angle is θ y ), the deflected +1st order diffraction beam passes through the intermediate optical component 3 and irradiates the optical fiber array 2. The Y coordinate Y of the exit position of the +1st order diffraction beam in the optical fiber array 2 is +1 The Y coordinate Y of the target port (a second port) t Same, that is, Y +1 =Y t .

[0181] The blazed grating formed by the silicon-based liquid crystal 4 will also deflect the crosstalk order diffracted light beam in the port plane; wherein the Y coordinate Y0 of the 0th order diffracted light beam at the exit position in the optical fiber array 2 is the same as the Y coordinate Y of the first port D0. com Same, that is, Y0=Y com , the Y coordinate Y of the -1st order diffraction beam at the exit position in the optical fiber array 2 -1 The Y coordinate of the second port c The same; and Y +1 and Y -1 Symmetrical about the X coordinate axis, that is, Y t =-Y c .

[0182] If the silicon-based liquid crystal 4 adopts a one-dimensional diffraction grating that can only form a blazed grating in the second direction, it is equivalent to a reflecting mirror in the first direction, so that the diffraction light beam formed by the blazed grating in the second direction is reflected in the dispersion plane, and the X coordinate of the diffraction light beam of each diffraction order is 0, which is equal to the X coordinate of the second port in the second part 22.

[0183] Therefore, if Fig.21A Part (a) of Fig. 21B Part (a) and Fig. 22 As shown in part (a) of the figure, when the target port is the second port in the second part 22, the silicon-based liquid crystal 4 can use a one-dimensional diffraction grating to deflect the +1-order diffracted light beam to the target port for emission. As for the crosstalk order, since the first part 21 and the second part 22 are staggered in the dispersion direction X, the 0-order and all negative-order diffracted light beams will not enter the port in the optical fiber array 2.

[0184] When the target port is the second port in the first part 21, the one-dimensional diffraction grating of the silicon-based liquid crystal 4 cannot make the +1-order (target order) diffracted light beam reach the target port (X coordinate is -p) for emission. In this case, the silicon-based liquid crystal 4 can use a two-dimensional diffraction grating that can form a blazed grating in both the first direction and the second direction.

[0185] like Fig.21A Part (b) of Fig. 21B Part (b) and Fig. 22 As shown in part (b) of FIG. 1 , the silicon-based liquid crystal 4 controls the target pixel area to also form a blazed grating in the first direction, and the blazed grating can diffract and deflect the incident light beam, and deflect the +1-order diffracted light beam in the dispersion plane (the deflection angle is θ x ), the deflected +1st order diffraction beam passes through the intermediate optical component 3 and irradiates the optical fiber array 2. The X coordinate X of the exit position of the +1st order diffraction beam in the optical fiber array 2 is +1 The X coordinate of the target port (a second port) t Same; X +1 =X t =-p.

[0186] The blazed grating formed by the silicon-based liquid crystal 4 will also deflect the crosstalk order diffracted light beam in the dispersion plane; wherein the X coordinate X0 of the 0th order diffracted light beam at the exit position in the optical fiber array 2 is the same as the X coordinate X0 of the first port D0. com Same, X0=X com = 0; the exit positions of the diffracted beams of other crosstalk orders in the optical fiber array 2 are all located outside the port. For example, the exit position X coordinate of the -1 order diffracted beam in the optical fiber array 2 is -1 It is +p and is located outside the port.

[0187] It can be seen from this that in the wavelength selection switch 1 provided in this embodiment, only the diffracted light beam of the target order (+1 order) can be emitted through the target port in the wave drop scenario; for the case where the target port is the second port in the first part 21, the silicon-based liquid crystal 4 can use a two-dimensional diffraction grating to achieve two-dimensional deflection, which can prevent the diffracted light beam of the crosstalk order from entering the optical fiber port in the optical fiber array 2, which is beneficial to the improvement of port isolation and the reduction of signal crosstalk between ports. For the case where the target port is the second port in the second part 22, the silicon-based liquid crystal 4 can use a one-dimensional diffraction grating, and the diffracted light beams of the 0th order and all negative orders cannot enter the optical fiber port, which can effectively improve the crosstalk problem caused by the diffracted light beam of the crosstalk order entering the optical fiber port in the optical fiber array 2, thereby facilitating the improvement of port isolation and the reduction of signal crosstalk between ports. In addition, the use of a one-dimensional diffraction grating by the silicon-based liquid crystal 4 can further improve the port insertion loss, which is beneficial to improving the performance of the wavelength selection switch 1.

[0188] In some embodiments, when the target port is the second port in the second part 22, the silicon-based liquid crystal 4 can adopt a two-dimensional diffraction grating working mode, which can not only deflect the +1 order (target order) diffraction light beam to the target port for output, but also avoid the diffraction light beam of the crosstalk order from entering the optical fiber port, which is beneficial to improving the port isolation and reducing the signal crosstalk between ports.

[0189] The working principle of the wavelength selective switch 1 using the above optical fiber array 2 in the wavelength adding scenario is:

[0190] In the wave loading scenario, any second port is an incident port for receiving an incident light beam, and the incident port may also be referred to as a source port; the first port D0 is a target port for outputting an outgoing light beam.

[0191] Fig.23A A schematic diagram of a port plane optical path of a wavelength selective switch provided in an embodiment of the present application in a wavelength loading scenario; Fig. 23B A schematic diagram of a dispersion plane optical path of a wavelength selective switch in a wave loading scenario provided by an embodiment of the present application; Fig.24 A diagram showing the position relationship between the diffracted light beam and the optical fiber array of the wavelength selective switch provided in the embodiment of the present application in the wave-adding scenario; wherein: Fig.23A Part (a) of Fig. 23B Part (a) and Fig.24 Part (a) in the example is the case where the source port is the second port in the first part 21. Fig.23A Part (b) of Fig. 23B Part (b) and Fig.24 Part (b) in the figure is the case where the source port is the second port in the second part 22 .

[0192] like Fig.23A and Fig.24 As shown, after the incident light beam is incident from the source port, it passes through the intermediate optical component 3 and then irradiates the target pixel area on the silicon-based liquid crystal 4.

[0193] The silicon-based liquid crystal 4 controls the target pixel area to form a blazed grating in the second direction, which can diffract and deflect the incident light beam, deflecting the +1 order (target order) diffracted light beam in the port plane (the deflection angle is θ y ), the deflected +1-order diffraction beam passes through the intermediate optical component 3 and irradiates the optical fiber array 2; the Y coordinate Y of the exit position of the +1-order diffraction beam in the optical fiber array 2 is +1 The Y coordinate Y of the target port (first port D0) com Same, that is, Y +1 =Y com .

[0194] The blazed grating formed by the silicon-based liquid crystal 4 will also deflect the crosstalk order diffracted light beam in the port plane; wherein the Y coordinate Y0 of the 0th order diffracted light beam at the exit position in the optical fiber array 2 is the same as the Y coordinate Y of a second port. c Same, and Y0=-Y c ; -Y coordinate Y of the exit position of the first-order diffracted beam in the optical fiber array 2 -1 Same as the Y coordinate of the other second port, or outside the port.

[0195] If the silicon-based liquid crystal 4 adopts a one-dimensional diffraction grating that can only form a blazed grating in the second direction, it is equivalent to a reflecting mirror in the first direction, thereby reflecting the diffracted light beam formed by the blazed grating in the second direction in the dispersion plane. When the source port is the second port in the second part 22, the X coordinate of the diffracted light beam of each diffraction order is 0, which is the same as the target port (X coordinate is 0); when the source port is the second port in the first part 21, the X coordinate of the diffracted light beam of each diffraction order is +p, which is different from the target port (X coordinate is 0).

[0196] Therefore, if Fig.23A Part (a) of Fig. 23B Part (a) and Fig.24 As shown in part (a), when the source port is the second port in the second part 22, the silicon-based liquid crystal 4 uses a one-dimensional diffraction grating to deflect the +1-order diffraction beam to the target port for emission; for the crosstalk order, since the first port D0 and the second part 22 are offset in the dispersion direction X, the 0th order and all negative order diffraction beams will not enter the port in the optical fiber array 2.

[0197] When the source port is the second port in the first part 21, the one-dimensional diffraction grating of the silicon-based liquid crystal 4 cannot make the +1-order (target order) diffracted light beam reach the target port (X coordinate is 0) for emission. In this case, the silicon-based liquid crystal 4 can use a two-dimensional diffraction grating that can form a blazed grating in both the first direction and the second direction.

[0198] like Fig.23A Part (b) of Fig. 23B Part (b) and Fig.24 As shown in part (b) of the figure, the silicon-based liquid crystal 4 controls the target pixel area to also form a blazed grating in the first direction, and the blazed grating can diffract and deflect the incident light beam, and deflect the +1 order (target order) diffracted light beam in the dispersion plane (the deflection angle is θ x ), the deflected +1-order diffraction beam passes through the intermediate optical component 3 and irradiates the optical fiber array 2; and the X coordinate X of the exit position of the +1-order diffraction beam in the optical fiber array 2 is +1 The X coordinate X of the target port (first port D0)com Same; X +1 =X com =0.

[0199] The blazed grating formed by the silicon-based liquid crystal 4 will also deflect the diffracted beams of the crosstalk order in the dispersion plane. In this embodiment, the diffracted beams of the crosstalk order are all projected at the position outside the port. For example, the X coordinate X0 of the position where the 0th order diffracted beam is emitted from the optical fiber array 2 is +p; the X coordinate X0 of the position where the -1st order diffracted beam is emitted from the optical fiber array 2 is -1 is +2p.

[0200] It can be seen from this that in the wavelength selection switch 1 provided in this embodiment, only the diffracted light beam of the target order (+1 order) can be emitted through the target port in the wave loading scenario. For the case where the source port is the second port in the first part 21, the silicon-based liquid crystal 4 can use a two-dimensional diffraction grating to achieve two-dimensional deflection, which can prevent the diffracted light beam of the crosstalk order from entering the optical fiber port in the optical fiber array 2, which is beneficial to the improvement of directivity and the reduction of signal crosstalk between ports. For the case where the target port is the second port in the second part 22, the silicon-based liquid crystal 4 can use a one-dimensional diffraction grating, and the diffracted light beams of the 0th order and all negative orders cannot enter the optical fiber port, which can effectively improve the crosstalk problem caused by the diffracted light beam of the crosstalk order entering the optical fiber port in the optical fiber array 2, thereby facilitating the improvement of directivity and the reduction of signal crosstalk between ports. In addition, the use of a one-dimensional diffraction grating by the silicon-based liquid crystal 4 can further improve the port insertion loss, which is beneficial to improving the performance of the wavelength selection switch 1.

[0201] In some embodiments, when the source grating is the second port in the second part 22, the silicon-based liquid crystal 4 can adopt the working mode of a two-dimensional diffraction grating, which can not only deflect the +1 order (target order) diffraction light beam to the target port for output, but also avoid the diffraction light beam of the crosstalk order from entering the optical fiber port, which is beneficial to improving the directionality and reducing the signal crosstalk between ports.

[0202] Based on the above content, it can be seen that in the wavelength selective switch 1 provided in this embodiment, the optical fiber array 2 includes a first port D0 and a plurality of second ports (D1 to D N ), multiple second ports (D1 to D N ) includes a first portion 21 and a second portion 22 located on both sides of a first reference line L1; the first portion 21, the second portion 22 and the first port D0 are arranged in a "biased, asymmetric" manner, the first port D0 and the second portion 22 are both located on the second reference line L2, and the first portion 21 is located on one side of the second reference line L2. The silicon-based liquid crystal 4 adopts a bilateral deflection and two-dimensional grating working mode, and in some cases, the silicon-based liquid crystal 4 can adopt a one-dimensional diffraction grating working mode.

[0203] With such a design, on the one hand, the bilateral deflection adopted by the silicon-based liquid crystal 4 can reduce the diffraction deflection angle required by the silicon-based liquid crystal 4, and for the same number of ports, the port insertion loss can be reduced, or for the same port insertion loss, the number of ports can be doubled. On the other hand, the optical fiber array 2 adopts a "biased, asymmetric" arrangement mode, and combined with the working mode of the two-dimensional grating or one-dimensional grating of the silicon-based liquid crystal 4, it can improve the situation where the diffracted light beam of the crosstalk order enters the port in the optical fiber array 2 to generate signal crosstalk, and effectively suppress the signal crosstalk between the ports, which is beneficial to improve the isolation of the down-wave scene and the directionality of the up-wave scene.

[0204] In addition, by setting the first distance and the third distance to 0 and the second distance to p, the requirements for the diffraction deflection angle range of the silicon-based liquid crystal 4 in the dispersion direction X can be reduced while ensuring the compactness of the port arrangement in the optical fiber array 2, which is beneficial to reducing the port insertion loss and improving the performance of the wavelength selection switch 1.

[0205] In the above embodiment, the first distance and the third distance are 0, and the second distance is p. However, the optical fiber array 2 designed in which the first port D0 and the second part 22 are both located on the second reference line L2, and the first part 21 is located on one side of the second reference line L2 is not limited to this. It is sufficient that the spacing between the positive projection positions of the first port D0 and the first part 21 on the first reference line L1 is less than or equal to p. Exemplarily, the first distance and the third distance are both 0, and the second distance can be any value less than or equal to 2p, for example, 0.5p, 1.5p, 2p.

[0206] It can be seen from the above description of the working principle that the smaller the second distance is, the lower the requirement for the diffraction deflection angle of the silicon-based liquid crystal 4 in the dispersion direction X is. Therefore, under the condition of meeting other requirements, a smaller second distance should be selected as much as possible.

[0207] The present application embodiment provides another wavelength selective switch 1, such as Fig.25 As shown, in the optical fiber array 2 of the wavelength selective switch 1, the first port D0 is located on one side of the second reference line L2, for example, on the side corresponding to the negative direction of the X-coordinate axis, and for example, on the side corresponding to the positive direction of the X-coordinate axis. The first part 21 and the second part 22 are located on the other side of the second reference line L2; and the first part 21 and the second part 22 are aligned in the dispersion direction X; the distance of the first port D0 relative to the second reference line L2 is equal to the distance of the first part 21 relative to the second reference line L2; in this case, the first distance, the second distance and the third distance are all greater than 0 and equal. In addition, the first distance, the second distance and the third distance are all less than or equal to 2 times the port size.

[0208] For example, Fig.25As shown, the first port D0 is offset by p in the positive direction of the X-coordinate axis, and the first part 21 and the second part 22 are offset by p in the negative direction of the X-coordinate axis as a whole; in this case, the X coordinate of the first port D0 is +p, and the Y coordinate is 0; the X coordinates of all the second ports are -p. The first distance, the second distance, and the third distance are all p.

[0209] The working principle of the wavelength selective switch 1 using the above optical fiber array 2 in the wavelength drop scenario is:

[0210] In the down-wave scenario, the first port D0 is an incident port for receiving an incident light beam, and any second port is a target port for outputting an outgoing light beam. Fig.26A A schematic diagram of the plane optical path of the port of the wavelength selective switch provided in the embodiment of the present application in the wave-down scenario, Fig.26B A schematic diagram of the dispersion plane optical path of the wavelength selective switch provided in the embodiment of the present application in the wavelet drop scenario, Fig. 27 The relationship diagram of the position of the diffracted light beam and the optical fiber array in the wavelength selective switch provided in the embodiment of the present application in the wave-down scenario; Fig.26A , Fig.26B and Fig. 27 As shown, after the incident light beam is incident from the first port D0 , it passes through the intermediate optical component 3 and then irradiates the target pixel area on the silicon-based liquid crystal 4 .

[0211] The silicon-based liquid crystal 4 controls the target pixel area to form a blazed grating in the second direction, which can diffract and deflect the incident light beam, deflecting the +1 order (target order) diffracted light beam in the port plane (the deflection angle is θ y ), the deflected +1st order diffraction beam passes through the intermediate optical component 3 and irradiates the optical fiber array 2. The Y coordinate Y of the exit position of the +1st order diffraction beam in the optical fiber array 2 is +1 The Y coordinate Y of the target port (a second port) t Same, that is, Y +1 =Y t .

[0212] The blazed grating formed by the silicon-based liquid crystal 4 will also deflect the crosstalk order diffracted light beam in the port plane; wherein the Y coordinate Y0 of the 0th order diffracted light beam at the exit position in the optical fiber array 2 is the same as the Y coordinate Y of the first port D0. com Same, that is, Y0=Y com , the Y coordinate Y of the -1st order diffraction beam at the exit position in the optical fiber array 2 -1 The Y coordinate of the second port c The same; and Y +1 and Y -1 Symmetrical about the X coordinate axis, that is, Y t =-Y c .

[0213] If the silicon-based liquid crystal 4 adopts a one-dimensional diffraction grating that can only form a blazed grating in the second direction, it is equivalent to a reflecting mirror in the first direction, thereby reflecting the diffracted light beam formed by the blazed grating in the second direction in the dispersion plane, and the X-coordinate of the diffracted light beam of each diffraction order is -p, which is the same as the X-coordinate of the target port.

[0214] Therefore, in the wavelet reduction scenario, the silicon-based liquid crystal 4 can use a one-dimensional diffraction grating to deflect the +1-order diffracted beam to the target port for emission; however, the crosstalk order will enter the second port, forming a strong signal crosstalk, and there is an isolation problem. This problem can be alleviated by optimizing the phase holographic algorithm of silicon-based liquid crystal 4, or combining other crosstalk reduction methods.

[0215] It can be seen from this that the wavelength selective switch 1 provided in this embodiment can use a one-dimensional diffraction grating on the silicon-based liquid crystal 4 to allow the diffracted light beam of the target order (+1 order) to be emitted through the target port in the wave drop scenario, which can further improve the port insertion loss. The isolation problem can be alleviated by optimizing the holographic algorithm of the silicon-based liquid crystal 4 phase or other crosstalk reduction methods.

[0216] The working principle of the wavelength selective switch 1 using the above optical fiber array 2 in the wavelength adding scenario is:

[0217] In the wave loading scenario, any second port is used as an incident port for receiving an incident light beam, and the second port can be called a source port; the first port D0 is a target port for outputting an outgoing light beam. Fig.28A A schematic diagram of a port plane optical path of a wavelength selective switch provided in an embodiment of the present application in a wavelength loading scenario; Fig.28B A schematic diagram of a dispersion plane optical path of a wavelength selective switch in a wave loading scenario provided by an embodiment of the present application; Fig.29 The relationship diagram of the position of the diffracted light beam and the optical fiber array in the wavelength selective switch provided in the embodiment of the present application in the wave-up scenario; Fig.28A , Fig.28B and Fig.29 As shown, after the incident light beam is incident from the source port, it passes through the intermediate optical component 3 and then irradiates the target pixel area on the silicon-based liquid crystal 4.

[0218] The silicon-based liquid crystal 4 controls the target pixel area to form a blazed grating in the second direction, which can diffract and deflect the incident light beam, deflecting the +1 order (target order) diffracted light beam in the port plane (the deflection angle is θ y ), the deflected +1st order diffraction beam passes through the intermediate optical component 3 and irradiates the optical fiber array 2. The Y coordinate Y of the exit position of the +1st order diffraction beam in the optical fiber array 2 is +1 The Y coordinate Y of the target port (first port D0) com Same, that is, Y+1 =Y com .

[0219] The blazed grating formed by the silicon-based liquid crystal 4 will also deflect the crosstalk order diffracted light beam in the port plane; wherein the Y coordinate Y0 of the 0th order diffracted light beam at the exit position in the optical fiber array 2 is the same as the Y coordinate Y of a second port. c Same, and Y0=-Y c ; -Y coordinate Y of the exit position of the first-order diffracted beam in the optical fiber array 2 -1 Same as the Y coordinate of the other second port, or outside the port.

[0220] If the silicon-based liquid crystal 4 adopts a one-dimensional diffraction grating that can only form a blazed grating in the second direction, it is equivalent to a reflecting mirror in the first direction, thereby reflecting the diffracted light beam formed by the blazed grating in the second direction in the dispersion plane, and the X-coordinate of the diffracted light beam of each diffraction order is p, which is the same as the X-coordinate of the target port (second port).

[0221] Therefore, in the wave-up scenario, the silicon-based liquid crystal 4 can use a one-dimensional diffraction grating to deflect the +1-order diffraction light beam to the target port for output; for the crosstalk order, since the first part 21 and the second part 22 are aligned in the dispersion direction X, they are staggered from the first port D0, and therefore, the diffraction light beam of the crosstalk order cannot enter the port in the optical fiber array 2.

[0222] As can be seen from the above, in the wavelength selective switch 1 provided in this embodiment, in the wave adding scenario, only the diffracted light beam of the target order (+1 order) can be emitted through the target port, and the diffracted light beam of the crosstalk order cannot enter the optical fiber port in the optical fiber array 2, thereby achieving improved directionality and reducing signal crosstalk between ports.

[0223] Based on the above content, it can be seen that in the wavelength selective switch 1 provided in this embodiment, the optical fiber array 2 includes a first port D0 and a plurality of second ports (D1 to D N ), multiple second ports (D1 to D N ) includes a first portion 21 and a second portion 22 located on both sides of a first reference line L1. The first portion 21, the second portion 22 and the first port D0 are arranged in a "biased, asymmetric" manner, the first port D0 is located on one side of the second reference line L2, and the first portion 21 and the second portion 22 are located on the other side of the second reference line L2; the first portion 21 and the second portion 22 are aligned in the dispersion direction X; the distance of the first port D0 relative to the second reference line L2 is equal to the distance of the first portion 21 relative to the second reference line L2. The silicon-based liquid crystal 4 can adopt the working mode of bilateral deflection and one-dimensional grating in both the upper wave scene and the lower wave scene.

[0224] With such a design, on the one hand, the bilateral deflection adopted by the silicon-based liquid crystal 4 can reduce the diffraction deflection angle required by the silicon-based liquid crystal 4, and for the same number of ports, the port insertion loss can be reduced, or for the same port insertion loss, the number of ports can be doubled. On the other hand, the optical fiber array 2 adopts a "biased, asymmetric" arrangement. In the wave-up scenario, the silicon-based liquid crystal 4 adopts a one-dimensional diffraction grating to allow the diffracted light beam of the target order (+1 order) to be emitted through the target port, and can effectively avoid the diffracted light beam of the non-+1 order crosstalk order from entering the port in the optical fiber array 2 to generate signal crosstalk, thereby effectively suppressing the signal crosstalk between ports, which is beneficial to improving the directionality of the wave-up scenario. In addition, the silicon-based liquid crystal 4 adopts a one-dimensional diffraction grating, which can improve the problem of port insertion loss.

[0225] In the wave-adding scenario, the one-dimensional diffraction grating of the silicon-based liquid crystal 4 can make the diffracted beam of the target order (+1 order) be emitted through the target port, which can further improve the port insertion loss. The isolation problem can be alleviated by optimizing the holographic algorithm of the silicon-based liquid crystal 4 phase or other crosstalk reduction methods.

[0226] In some embodiments, in the down-wave scenario, the silicon-based liquid crystal 4 can use a two-dimensional diffraction grating, which can not only deflect the +1 order (target order) diffraction beam to the target port for emission, but also prevent the diffraction beam of the crosstalk order from entering the optical fiber port, which is beneficial to improving isolation and reducing signal crosstalk between ports.

[0227] In the above embodiment, the first distance, the second distance and the third distance are all p, but the optical fiber array 2 designed in which the first port D0 is located on one side of the second reference line L2, the first part 21 and the second part 22 are located on the other side of the second reference line L2; and the first part 21 and the second part 22 are aligned in the dispersion direction X is not limited thereto, and the spacing between the orthographic projection positions of the first port D0 and the first part 21 on the first reference line L1 is greater than or equal to For example, the first distance, the second distance and the third distance are equal, and can be greater than or equal to and any value less than or equal to 2p, for example, 0.5p, p. 1.5p, 2p.

[0228] The above embodiments show several arrangements of the optical fiber array 2 in the wavelength selective switch 1, but the embodiments of the present application are not limited thereto. The arrangement of the optical fiber array 2 may include the following types of arrangements:

[0229] In some embodiments, the optical fiber array 2 may be arranged in such a manner that the orthographic projection positions of the first portion 21 and the second portion 22 on the first reference line L1 are the same, and the orthographic projection positions of the first port D0 and the first portion 21 on the first reference line L1 are different. Fig.17 and Fig.25 The arrangement shown belongs to this arrangement type, and the arrangement type also includes other arrangements. Exemplarily, the first port D0 is located on one side of the second reference line L2, the first part 21 and the second part 22 are located on the other side of the second reference line L2, and the first part 21 and the second part 22 are aligned in the dispersion direction X; the first distance is not equal to the second distance. In another exemplary embodiment, the first port D0, the first part 21 and the second part 22 are located on the same side of the second reference line L2, and the first part 21 and the second part 22 are aligned in the dispersion direction X; the first distance is not equal to the second distance. In another exemplary embodiment, the first port D0 is located on one side of the second reference line L2, and the first part 21 and the second part 22 are located on the second reference line L2;

[0230] For the above arrangement type, in some embodiments, the distance between the first port D0 and the orthographic projection position of the first portion 21 on the first reference line L1 is greater than or equal to times the port size.

[0231] In some embodiments, the optical fiber array 2 can be arranged in such a manner that the orthographic projection positions of the first portion 21 and the second portion 22 on the first reference line L1 are different; the orthographic projection position of the first port D0 and the first portion 21 on the first reference line L1 are the same, or the orthographic projection position of the first port D0 and the second portion 22 on the first reference line L1 are the same. Fig. 20 The arrangement shown belongs to this arrangement type, and this arrangement type also includes other arrangements. Exemplarily, the first part 21 is located on the second reference line L2, the second part 21 is located on one side of the second reference line L2, and the first port D0 is aligned with the first part 21 or the second part 22 in the dispersion direction X. In another exemplary embodiment, the first port D0, the first part 21 or the second part 22 are not on the second reference line L2, the first part 21 and the second part 22 are located on the same side or both sides of the second reference line L2, and the first port D0 is aligned with the first part 21 or the second part 22 in the dispersion direction X.

[0232] In some embodiments, the arrangement of the optical fiber array 2 may be an arrangement type in which the orthographic projection positions of the first port D0, the first portion 21, and the second portion 22 on the first reference line L1 are all different. Exemplarily, one of the first port D0, the first portion 21, and the second portion 22 is located on the second reference line L2; in another exemplary embodiment, the first port D0, the first portion 21, and the second portion 22 are not on the second reference line L2; the three are located on the same side or both sides of the second reference line L2.

[0233] The technical effects and principles that can be achieved by the optical fiber array 2 arranged in the above manner can be referred to the above description and will not be repeated here.

[0234] In some embodiments, the second ports in the first portion 21 and the second ports in the second portion 22 are arranged at the same interval, and the closest distance to the first reference line L1 in the first portion 21 is equal to the closest distance to the first reference line L1 in the second portion 22 .

[0235] In order to better realize the bilateral deflection of the LCOS 4 , the number of the second ports in the first part 21 and the second part 22 is the same and they are symmetrically arranged with respect to the first reference line L1 .

[0236] In some embodiments, the number of second ports in the first portion 21 and the second portion 22 is substantially the same, where substantially the same means that the difference between the two numbers does not exceed 5% of the larger number.

[0237] In the above embodiment, the second ports in the first part 21 and the second part 22 are arranged in a straight line, and the arrangement line is parallel to the second reference line L2. In this way, on the one hand, the optical fiber ports arranged in a straight line are easier to manufacture and ensure position accuracy, thereby reducing the difficulty of manufacturing the optical fiber array 2; on the other hand, the parallel arrangement with the second reference line L2 is more conducive to port switching, which can reduce the complexity of the port switching process, so that the port switching can be realized more quickly and accurately, which is conducive to improving the performance of the wavelength selective switch 1.

[0238] However, the embodiments of the present application are not limited thereto. For example, the embodiments of the present application also provide another wavelength selective switch, in which the optical fiber array includes a first port and a plurality of second ports.

[0239] Wherein, the first port is arranged on the first reference line.

[0240] The multiple second ports are divided into a first part and a second part located on both sides of a first reference line, and at least one of the first port, the first part and the second part is located on one side of the second reference line; when the first port is set at the center of the optical path, the first part and the second part are arranged asymmetrically relative to the first port.

[0241] It can be seen from this that the optical fiber array provided in this embodiment does not limit the arrangement of the first part. The second ports in the first part can be arranged along a straight line parallel to the second reference line, along a straight line not parallel to the second reference line, along a regular or irregular curve, or along a combination line; wherein the combination line can be formed by connecting a plurality of different straight lines, connecting a plurality of different curves, or connecting a straight line and a curve.

[0242] The optical fiber array provided in this embodiment does not limit the arrangement of the second part. The second ports in the second part can be arranged along a straight line parallel to the second reference line, along a straight line not parallel to the second reference line, along a regular or irregular curve, or along a combination line; wherein the combination line can be formed by connecting a plurality of different straight lines, connecting a plurality of different curves, or connecting a straight line and a curve.

[0243] In this case, the second distance is the maximum distance of the second port in the first part relative to the second reference line; the third distance is the maximum distance of the second port in the second part relative to the second reference line; and the first distance, the second distance and the third distance are all less than or equal to 2 times the port size.

[0244] The wavelength selective switch using the above-mentioned optical fiber array can also improve the problem of crosstalk between ports and port insertion loss affecting the expansion of the number of ports. Its working principle and technical effects that can be achieved can be referred to the above description and will not be repeated here.

[0245] In the wavelength selective switch 1 provided in the embodiment of the present application, the intermediate optical component 3 is used to optically adjust the light beam transmitted between the silicon-based liquid crystal 4 and the optical fiber array 2. The optical adjustment here may include wave splitting and wave combining; it may also include at least one of polarization state conversion, collimation, light spot transformation and changing the direction of the light path.

[0246] In this embodiment, the intermediate optical component 3 includes a switching lens, three dispersion lenses and a diffraction grating. Fig.11A As shown, in the optical path corresponding to the wavelength selective switch 1 and the port plane, the switching lens 31 forms the basic structure of the 2f optical system; wherein the focal length of the switching lens 31 is f sw , the optical fiber array 2 and the silicon-based liquid crystal 4 are respectively located at the front and rear focal planes of the switching lens 31. Through the switching lens 31, the optical path converts the deflection of the silicon-based liquid crystal 4 on the light beam into a translation relative to the optical fiber port in the optical fiber array 2.

[0247] like Fig. 11BAs shown, in the optical path corresponding to the wavelength selective switch 1 and the dispersion plane, three dispersion lenses constitute the basic structure of a 6f optical system; the first lens 32 constitutes the basic structure of a 2f optical system, and the second lens 33 and the third lens 35 constitute a 4f optical system; wherein the optical fiber array 2 is located at the front focal plane of the first lens 32, the diffraction grating 34 and the silicon-based liquid crystal 4 are respectively located at the front focal plane and the back focal plane of the third lens 35, and the focal length of the third lens 35 is f d .

[0248] Through the first lens 32, the optical path converts the deflection of the silicon-based liquid crystal 4 on the light beam into a translation relative to the optical fiber port in the optical fiber array 2; through the second lens 33 and the third lens 35, the optical path splits the different wavelengths in the incident light beam and disperses them to different positions of the silicon-based liquid crystal 4 according to the wavelength, or combines the light beams of different wavelengths reflected from different positions of the silicon-based liquid crystal 4 and reconstructs them into an outgoing light beam.

[0249] In the above embodiment, the wavelength selective switch 1 uses silicon-based liquid crystal 4 as a spatial light modulator. Silicon-based liquid crystal 4 has the characteristics of a flexible grid (Flex-Grid), which supports the flexible allocation of the wavelength selective switch channel bandwidth. However, the embodiment of the present application is not limited to this. The wavelength selective switch provided in the embodiment of the present application can also use a liquid crystal (LC) device, a micro-electro-mechanical system (MEMS) device or other devices made based on adjustable electro-optical media as a spatial light modulator.

[0250] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A wavelength selective switch, characterized in that: It includes an optical fiber array and a spatial light modulator; the optical fiber array includes a first port and a plurality of second ports; The plurality of second ports are divided into a first part and a second part located on both sides of the first reference line, and at least one of the first port, the first part and the second part is located on one side of the second reference line; when the first port is arranged at the center of the optical path, the first part and the second part are arranged asymmetrically relative to the first port; In the optical fiber array, the distance between the first port and the second reference line is a first distance, the maximum distance between the second port in the first part and the second reference line is a second distance; the maximum distance between the second port in the second part and the second reference line is a third distance; the first distance, the second distance and the third distance are all less than or equal to 2 times the port size; Among them, the center of the optical path is the position where the input light spot and the output light spot in the optical fiber array overlap when the spatial light modulator is used as a reflecting mirror; the first reference line is parallel to the dispersion direction, the second reference line is parallel to the port direction, and the intersection of the first reference line and the second reference line is the center of the optical path; the port size is the size of the first port in the dispersion direction.

2. The wavelength selective switch according to claim 1, characterized in that: The first part and the second part each include at least two second ports, wherein the second ports in the first part are arranged along a straight line parallel to the second reference line, and the second ports in the second part are arranged along a straight line parallel to the second reference line.

3. The wavelength selective switch according to claim 1 or 2, characterized in that: The first port is arranged on a first reference line.

4. The wavelength selective switch according to any one of claims 1 to 3, characterized in that: The first port, the first portion, and the second portion are located on the same side of the second reference line, and have the same orthographic projection position on the first reference line.

5. The wavelength selective switch according to claim 4, characterized in that: The first port, the second port in the first part, and the second port in the second part are at equal distances from the second reference line, and are all equal to 0.5 times the size of the port.

6. The wavelength selective switch according to claim 2, characterized in that: The orthographic projection positions of the first portion and the second portion on the first reference line are the same, and the orthographic projection positions of the first port and the first portion on the first reference line are different.

7. The wavelength selective switch according to claim 6, characterized in that: The distance between the first port and the first portion of the positive projection position on the first reference line is greater than or equal to times the port size.

8. The wavelength selective switch according to claim 6 or 7, characterized in that: The first port is located on the second reference line; or The first portion and the second portion are both located on the second reference line; or The first port and the first portion are respectively located on two sides of the second reference line.

9. The wavelength selective switch according to claim 6 or 7, characterized in that: The first port and the first portion are respectively located on both sides of the second reference line, and the first port and a second port in the first portion are equidistant from the second reference line.

10. The wavelength selective switch according to claim 9, characterized in that: The distances of the first port and the second port in the first part relative to the second reference line are both equal to the port size. or 0.5 times.

11. The wavelength selective switch according to claim 2, characterized in that: The orthographic projection positions of the first part and the second part on the first reference line are different; The first port is located at the same position as an orthographic projection of the first portion or the second portion on the first reference line.

12. The wavelength selective switch according to claim 11, characterized in that: The first portion is located on the second reference line; or the second portion is located on the second reference line; or The first portion and the second portion are respectively located on two sides of the second reference line.

13. The wavelength selective switch according to claim 11 or 12, characterized in that: The distance between the orthographic projection positions of the first portion and the second portion on the first reference line is equal to the port size.

14. The wavelength selective switch according to claim 2, characterized in that: The orthographic projection positions of the first port, the first portion, and the second portion on the first reference line are all different.

15. The wavelength selective switch according to claim 14, characterized in that: The first port is located at the center of the optical path; The first portion and the second portion are located on the same side of the second reference line; or, the first portion and the second portion are located on two sides of the second reference line respectively.

16. The wavelength selective switch according to any one of claims 1 to 15, characterized in that: The number of second ports in the first part and the second part is equal; In the port direction, the second ports in the first part and the second ports in the second part are arranged at the same interval; The minimum distance between the second port in the first portion and the first reference line is equal to the minimum distance between the second port in the second portion and the first reference line.

17. The wavelength selective switch according to any one of claims 1 to 16, characterized in that: The wavelength selective switch further comprises an intermediate optical component located between the optical fiber array and the spatial light modulator; the intermediate optical component is used for optically adjusting the light beam transmitted between the optical fiber array and the spatial light modulator.

18. The wavelength selective switch according to any one of claims 1 to 17, characterized in that: The spatial light modulator is liquid crystal on silicon.

19. A node device, characterized in that: Comprising at least one wavelength selective switch according to any one of claims 1 to 18.

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