Compact matrix optical switch and optical communication device based on two-dimensional prism group

Abstract

The present application belongs to the field of optical fiber communication, and specifically discloses a compact matrix optical switch and optical communication equipment based on a two-dimensional prism group. Through the present application, a two-dimensional prism group is set in front of each of the two LCOS chips, and the two-dimensional prism has a wedge angle in both directions, which can produce two-dimensional refraction of the light beam, folding the matrix optical switch from a planar W-shaped optical path to a three-dimensional optical path, and making the structure of the optical switch more compact; the incident angle of the light beam on the LCOS chip is reduced, and the diffraction efficiency is increased, thereby reducing the loss of the matrix optical switch.

Description

Technical Field

[0001] The present application belongs to the field of optical fiber communication, and more specifically, to a compact matrix optical switch and optical communication equipment based on a two-dimensional prism group. Background Art

[0002] With the promotion and application of 5G communications and the development of mobile Internet, network traffic has grown rapidly. As one of the Internet infrastructures, data centers are becoming larger and larger and their business is becoming busier. After introducing fiber optic interconnection technology, data centers are introducing large-scale matrix optical switches (>100×100 ports) to improve access efficiency.

[0003] In the past two years, in order to support the development of artificial intelligence, people are building a large number of computing centers. Between the various computing units in the computing centers, data needs to be exchanged in real time through large-scale matrix optical switches to improve the efficiency of parallel computing.

[0004] Large-scale matrix optical switches have a wide range of application needs in data centers and computing centers. There are many technical solutions to achieve large-scale matrix optical switches, but there are only three technical solutions with practical prospects: 1) DirectLight technology, which drives the optical fiber behind two microlens arrays through piezoelectric materials to achieve optical path switching; 2) 3D MEMS technology, which achieves large-scale optical path switching through two MEMS micromirror arrays; 3) Liquid crystal on silicon (LCOS) technology, which achieves beam deflection and optical path switching through two pure phase-modulated LCOS chips. The first solution can realize a matrix optical switch with a large number of ports, but the drive is complex and the drive voltage is high; the second solution has the advantages of simple optical path and low loss, but the MEMS chip is expensive and the yield is low.

[0005] The third solution is the LCOS chip that controls the beam deflection. It is a fully solid-state component. There is no mechanical moving part in the entire matrix optical switch, so it has the advantage of high reliability. In addition, the LCOS chip is much cheaper than the piezoelectric driver in the first solution and the MEMS chip in the second solution, and the driving voltage is lower, and the driving design is simpler.

[0006] like Figure 1 As shown in the figure, the LCOS matrix optical switch is usually composed of five parts: an optical front end, an LCOS chip, a concave reflector, an LCOS chip, and an optical back end, forming a W-shaped optical path in a plane. In order to avoid mutual interference between the optical front end, the concave reflector, and the optical back end, it is necessary to increase the incident angle of the light beam on the two LCOS chips, resulting in an oversized optical switch. In addition, the light beam obliquely incident on the LCOS chip at a large angle will reduce the diffraction efficiency and increase the loss of the optical switch. Summary of the invention

[0007] In view of the defects of the prior art, the purpose of this application is to provide a compact matrix optical switch and optical communication equipment based on a two-dimensional prism group, aiming to solve the problems that the existing matrix optical switch has a planar W-shaped optical path, resulting in excessive size of the optical switch and low diffraction efficiency, resulting in large optical switch losses.

[0008] To achieve the above-mentioned purpose, in a first aspect, the present application provides a compact matrix optical switch based on a two-dimensional prism group, comprising an optical front end, a first two-dimensional prism group, a first LCOS chip, a concave reflector, a second two-dimensional prism group, a second LCOS chip and an optical back end arranged in sequence along a three-dimensional W-shaped optical path;

[0009] The first LCOS chip and the second LCOS chip are both arranged on the focal plane of the concave reflector, and the three together constitute a 2F optical system;

[0010] The first two-dimensional prism group and the second two-dimensional prism group have the same structure, wherein the first two-dimensional prism group applies an additional deflection in the xz plane to two beams of mutually parallel linear polarized light after polarization diversity at each port of the optical front end through refraction on the xz plane, applies an additional deflection in the yz plane to two beams of mutually parallel linear polarized light after polarization diversity at each port of the optical front end through refraction on the yz plane, and the second two-dimensional prism group applies an additional deflection in the xz plane to the linear polarized light reflected by the concave reflector through refraction on the xz plane, so that the linear polarized light is corrected to be parallel to each other, and applies an additional deflection in the yz plane to the linear polarized light reflected by the concave reflector through refraction on the yz plane, so that the linear polarized light is parallel to the output light of the optical front end;

[0011] Under the premise that no driving voltage is applied to the first LCOS chip and the second LCOS chip, two groups of parallel light beams generated by polarization diversity from each port of the optical front end are successively refracted in two dimensions by the first two-dimensional prism group, reflected by the first LCOS chip, reflected by the concave reflector, and refracted in two dimensions by the second two-dimensional prism group, and then are incident on the center positions of the upper and lower halves of the second LCOS chip respectively.

[0012] Preferably, in the compact matrix optical switch, the first two-dimensional prism group, the first LCOS chip and the concave reflector need to simultaneously meet the following four conditions:

[0013]

[0014]

[0015]

[0016]

[0017] in, is the number of ports in the x direction of the optical front end, is the side length of the pixel area allocated to a single port on the first LCOS chip, is the length of the first LCOS chip, is the focal length of the concave reflector, is the angle between the incident light and the normal line of the incident surface of the first two-dimensional prism group in the x direction, is the angle between the outgoing light and the normal line of the outgoing surface of the first two-dimensional prism group in the x direction, is the refractive index of the first two-dimensional prism group, is the required distance between the concave reflector and the optical front end after folding, is the angle between the incident light and the normal line of the incident surface of the first two-dimensional prism group in the y direction, is the angle between the emitted light and the normal line of the emission surface of the first two-dimensional prism group in the y direction.

[0018] Preferably, the first two-dimensional prism group is an integrated structure, and its side view angle is a roof prism, and its top view angle is a wedge prism; or, its side view angle is two identical triangular prisms with thin ends aligned, and its top view angle is a wedge prism.

[0019] Preferably, the first two-dimensional prism group is composed of two one-dimensional prisms, one of which has a side viewing angle of a roof prism and a top viewing angle of flat glass, and the other has a side viewing angle of flat glass and a top viewing angle of a wedge prism; or, the side viewing angle of one of the prisms is two identical triangular prisms with their thin ends aligned and a top viewing angle of flat glass, and the other has a side viewing angle of flat glass and a top viewing angle of a wedge prism.

[0020] Preferably, the first two-dimensional prism group is an integrated structure, and its top view angle is a wedge-shaped prism, and the side view angle is that the thick ends of two quadrangular prisms with different wedge angles are aligned with the thin ends.

[0021] Preferably, the first two-dimensional prism group is composed of two one-dimensional prisms, one of which has a side viewing angle of a roof prism and a top viewing angle of a flat glass, and the other has a side viewing angle of a wedge prism and a top viewing angle of a wedge prism; or, the side viewing angle of one of the prisms is two identical triangular prisms with their thin ends aligned and a top viewing angle of a flat glass, and the other has a side viewing angle of a wedge prism and a top viewing angle of a wedge prism.

[0022] Preferably, the optical front end and the optical back end are arranged in parallel and merged into one optical front end.

[0023] Preferably, two LCOS chips are arranged in parallel and merged into one LCOS chip.

[0024] Preferably, the maximum diffraction deflection angle in the x direction generated by the corresponding block on the first LCOS chip is , maximum diffraction deflection angle in the y direction ,in, is the focal length of the concave reflector, Indicates the number of ports in the x direction of the optical front end. Indicates the number of ports in the Y direction of the optical front end. is the side length of the pixel area allocated to a single port on the first LCOS chip, is the number of ports of the optical front end, is the size of the pixel area allocated to a single port on the first LCOS chip.

[0025] To achieve the above-mentioned purpose, in a second aspect, the present application provides an optical communication device, comprising a compact matrix optical switch and a circuit control board as described in the first aspect; the circuit control board is used to provide a phase control signal for the first LCOS chip and the second LCOS chip in the compact matrix optical switch.

[0026] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the prior art:

[0027] The present application provides a compact matrix optical switch and optical communication device based on a two-dimensional prism group. A two-dimensional prism group is arranged in front of each of the two LCOS chips. The two-dimensional prism has a wedge angle in the x direction and a wedge angle in the y direction at the same time, and can produce two-dimensional refraction on the light beam. The first two-dimensional prism group applies an additional deflection in the xz plane to two mutually parallel linear polarized light beams after polarization diversity at each port of the optical front end through refraction on the xz plane, so as to reduce the deflection angle requirement of the first LCOS chip. The second two-dimensional prism group applies an additional deflection in the xz plane to the linear polarized light reflected by the concave reflector through refraction on the xz plane, so as to correct it to be parallel to each other. The additional deflection imposed by the former is offset to reduce the deflection angle requirement of the second LCOS chip, the incident angle of the light beam on the LCOS chip is reduced, the diffraction efficiency is increased, and thus the loss of the matrix optical switch is reduced; the first two-dimensional prism group applies an additional deflection in the yz plane to the two parallel linear polarized lights after polarization diversity at each port of the optical front end through refraction on the yz plane, and the second two-dimensional prism group applies an additional deflection in the yz plane to the linear polarized light reflected by the concave reflector through refraction on the yz plane, so that it is parallel to the output light of the optical front end. The two cooperate to fold the entire optical route of the matrix switch from a planar structure into a three-dimensional structure, and the structure of the optical switch is more compact. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall structure of a planar W-shaped matrix optical switch provided by the background technology.

[0029] Figure 2 This is a schematic diagram of the overall structure of a compact matrix optical switch based on a two-dimensional prism group provided in Example 1 of the present application.

[0030] Figure 3 It is a schematic diagram of the optical front-end structure provided in this application.

[0031] Figure 4 This is a schematic diagram of the overall structure of a compact matrix optical switch based on a two-dimensional prism group provided in Example 2 of the present application.

[0032] Figure 5 This is a schematic diagram of the overall structure of a compact matrix optical switch based on a two-dimensional prism group provided in Example 3 of the present application.

[0033] Figure 6 This is a schematic diagram of the overall structure of a compact matrix optical switch based on a two-dimensional prism group provided in Example 4 of the present application.

[0034] Figure 7 This is a schematic diagram of light beam deflection by a two-dimensional prism assembly provided in this application.

[0035] Figure 8 It is a schematic diagram of the two-dimensional prism group structure in Example 1 and Example 2 provided in the present application, wherein (a) and (c) are two integrated structures, and (b) and (d) are two combined structures.

[0036] Fig. 9 It is a schematic diagram of the two-dimensional prism group structure in Example 3 and Example 4 provided in the present application, wherein (a) and (c) are two integrated structures, and (b) and (d) are two combined structures.

[0037] Fig.10 is an equivalent optical path diagram of the 2F optical system provided in the present application, wherein (a) corresponds to no two-dimensional prism group, and (b) corresponds to the two-dimensional prism group. Figure 8 The two-dimensional prism group shown in (a) and the corresponding setting in (c) Figure 8 The two-dimensional prism group shown in (c).

[0038] Fig.11 This is a comparison diagram of the light spot position on the second LOCS chip with and without a two-dimensional prism group provided by the present application, wherein (a) corresponds to no two-dimensional prism group, and (b) corresponds to a two-dimensional prism group.

[0039] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0040] 1-optical front end, 2-first two-dimensional prism group, 3-first LCOS chip, 4-concave reflector, 5-second two-dimensional prism group, 6-second LCOS chip, 7-optical back end, 11-two-dimensional collimator array, 12-polarization beam splitter prism, 13-half-wave plate, 201, 202, 203, 204, 205, 206, 207, 208-one-dimensional prism. DETAILED DESCRIPTION

[0041] For ease of understanding, the English abbreviations and related technical terms involved in the embodiments of the present application are explained and described below.

[0042] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0043] like Figure 2 As shown, the present application provides a compact matrix optical switch based on a two-dimensional prism group, which consists of an optical front end 1, a first two-dimensional prism group 2, a first LCOS chip 3, a concave reflector 4, a second two-dimensional prism group 5, a second LCOS chip 6 and an optical back end 7.

[0044] The optical front end 1 transforms the small spot divergent beam at the output end of the optical fiber into a collimated beam with a large spot, and performs polarization diversity to obtain two parallel linear polarized beams with the same polarization state. The optical back end has the same structure as the optical front end, except that the beams are transmitted in the reverse direction; each port in the optical back end combines two parallel linear polarized beams with the same polarization state into one beam, which is then coupled to the output optical fiber through the fiber collimator.

[0045] like Figure 3 As shown, the optical front end 1 includes a two-dimensional collimator array 11, a polarization beam splitter prism 12 and a half-wave plate 13. The two-dimensional collimator array 11 has M×N ports, each of which transforms the small spot divergent light beam at the output end of the optical fiber into a collimated light beam with a large spot. The polarization beam splitter prism 12 is a glued prism composed of a triangular prism and an rhombus prism. A polarization beam splitter film is coated on the glued surface of the two prisms. It can transmit p-waves (polarized light with the light vector parallel to the paper surface) and reflect s-waves (polarized light with the light vector perpendicular to the paper surface). After a beam of randomly polarized light passes through the polarization beam splitter prism 12, two parallel linear polarized light beams with orthogonal polarization states are obtained. After one of the light beams passes through the half-wave plate 13, the polarization state of the two light beams is rotated 90°. Finally, the two light beams are parallel to each other and have the same polarization state, realizing polarization diversity. Therefore, in the optical front end 1, a group of ( After polarization diversity, two groups (each ) parallel beams with the same polarization state.

[0046] The pure phase-modulated LCOS chip is a pixelated element that can control the refractive index of the liquid crystal layer in each pixel through the electrically controlled birefringence effect, thereby controlling the phase delay of the reflected light beam of each pixel. LCOS can form a dynamic phase grating by controlling the phase of each pixel, control the (reflective) diffraction direction of the light beam, and can be adjusted dynamically. The LCOS chip consists of multiple blocks, each of which corresponds to a port of the optical front end of the matrix optical switch, and controls the diffraction direction of a beam of polarized light separated by polarization diversity, and guides it to the target output port.

[0047] The first LCOS chip 3 and the second LCOS chip 6 are both arranged on the focal plane of the concave reflector 4, forming a 2F optical system, and the light spots on the first LCOS chip 3 and the second LCOS chip 6 are of the same size. The first LCOS chip 3 and the second LCOS chip 6 are each divided into two upper and lower half areas, respectively processing a beam of polarized light separated by polarization diversity.

[0048] A first two-dimensional prism group 2 and a second two-dimensional prism group 5 are respectively arranged in front of the first LCOS chip 3 and the second LCOS chip 6. The first two-dimensional prism group 2 and the second two-dimensional prism group 5 have the same structure. A conventional one-dimensional prism has a wedge angle in only one direction, which can produce a one-dimensional deflection on the light beam; a two-dimensional prism has a wedge angle in both the x direction and the y direction, which can produce a two-dimensional deflection on the light beam.

[0049] The first two-dimensional prism group 2 arranged in front of the first LCOS chip 3 folds the plane optical path into a 3D optical path, and adjusts the incident position of the light spot on the second LCOS chip 6 and the direction of the diffracted light beam of the second LCOS chip 6. Specifically, 1) in the static state where no driving voltage is applied to the first LCOS chip 3, the light beams from all input ports can be sequentially passed through the first two-dimensional prism group 2 (x direction), the first LCOS chip 3 and the concave reflector 4, and the two beams of polarization diversity are respectively incident on the center position of the upper and lower halves of the second LCOS chip 6; 2) the entire optical path of the matrix optical switch is folded from a planar structure into a three-dimensional optical path, making the structure of the optical switch more compact; the incident angle of the light beam on the LCOS chip is reduced, and the diffraction efficiency is increased, thereby reducing the loss of the matrix optical switch.

[0050] The second two-dimensional prism group 5 arranged in front of the second LCOS chip 6, on the one hand, corrects the reflected light beams of the upper and lower halves of the second LCOS chip 6 to be parallel to each other to facilitate reception by the optical back end; on the other hand, it cooperates with the first two-dimensional prism group 2 (y direction) to realize folding of the optical path from a planar structure into a three-dimensional optical path.

[0051] This application provides four specific implementations of a two-dimensional prism assembly: Figure 2 and Figure 4-6As shown, it is also applicable to the first two-dimensional prism group 2 and the second two-dimensional prism group 5. The present application uses the first two-dimensional prism group 2 and the second two-dimensional prism group 5, Figure 1 The planar W-shaped optical path shown is folded into a 3D optical path, and the structure of the optical switch is more compact; the incident angle of the light beam on the LCOS chip is reduced, and the diffraction efficiency is increased, thereby reducing the loss of the matrix optical switch.

[0052] The first two-dimensional prism group 2 and the second two-dimensional prism group 5 have slopes in two dimensions. When the light beam passes through the first two-dimensional prism group 2 and the second two-dimensional prism group 5, additional deflection angles will be generated in the two dimensions. The deflection angles are related to the slope of the two-dimensional prism group and the refractive index of the material. The principle of the two-dimensional prism group deflecting the light beam in two dimensions is the same. Take the one-dimensional prism group as an example, Figure 7 As shown, let the inclination angle of the inclined surface of the one-dimensional prism group be , the refractive index of the material is The light beam is incident vertically on the surface of the one-dimensional prism group, and the angle between it and the normal line of the inclined surface of the one-dimensional prism group is , the angle between the light beam and the inclined surface after refraction is , then:

[0053] .

[0054] After being reflected by the first LCOS chip 3, the light beam passes through the inclined surface of the one-dimensional prism group again, and the angle between the light beam and the normal line of the inclined surface is , by geometric calculation we can get:

[0055] .

[0056] The light beam is refracted by the inclined plane again and then emerges. The angle between the emergent light and the inclined plane is , then:

[0057] .

[0058] The final angle between the outgoing light and the incident light is .

[0059] After the light beam passes through the one-dimensional prism group, the exit position is laterally offset. Assume that the distance from the midpoint of the inclined surface of the one-dimensional prism group to the first LCOS chip 3 is , then the lateral offset for:

[0060] .

[0061] In order to minimize the lateral offset, the first two-dimensional prism group 2 and the second two-dimensional prism group 5 should be close to the first LCOS chip 3 and the second LCOS chip 6, respectively, and the distance is less than 1 mm. The thickness of the first two-dimensional prism group 2 and the second two-dimensional prism group 5 is As small as possible. But the thickness If the thickness is too small, the processing difficulty will be increased and the prism will be fragile. Generally, the thinnest part of the first two-dimensional prism group 2 and the second two-dimensional prism group 5 is controlled to be larger than 0.3 mm.

[0062] In order to ensure that the first two-dimensional prism group 2 and the second two-dimensional prism group 5 can cover the light beams incident on the first LCOS chip 3 and the second LCOS chip 6, the length of the first two-dimensional prism group 2 in the xy plane is at least 2 mm greater than the length of the first LCOS chip 3, and the width in the xy plane is at least 2 mm greater than the width of the first LCOS chip 3. The length of the second two-dimensional prism group 5 in the xy plane is at least 2 mm greater than the length of the second LCOS chip 6, and the width in the xy plane is at least 2 mm greater than the width of the second LCOS chip 6.

[0063] Figure 1 The first two-dimensional prism group 2 has a slope in the x direction, which can make the two groups of light beams generated by polarization diversity incident on the upper and lower halves of the second LCOS chip 6 respectively. Assuming that the length of the first LCOS chip 3 is , the focal length of the concave reflector 4 is , then in the compact matrix optical switch, the first two-dimensional prism group, the first LCOS chip and the concave reflector must simultaneously meet the following two conditions:

[0064]

[0065]

[0066] in, is the length of the first LCOS chip, is the focal length of the concave reflector, is the angle between the incident light and the normal line of the incident surface of the first two-dimensional prism group in the x direction, is the angle between the outgoing light and the normal line of the outgoing surface of the first two-dimensional prism group in the x direction, is the refractive index of the first prism group.

[0067] The first two-dimensional prism group 2 also has a slope in the y direction, which can fold the light path. Suppose the required distance between the reflector 4 and the optical front end after folding is , then in the compact matrix optical switch, the first two-dimensional prism group, the first LCOS chip and the concave reflector must also meet the following two conditions at the same time:

[0068]

[0069]

[0070] in, is the required distance between the concave reflector and the optical front end after folding, is the angle between the incident light and the normal line of the incident surface of the first two-dimensional prism group in the y direction, is the angle between the emitted light and the normal line of the emission surface of the first two-dimensional prism group in the y direction.

[0071] Figure 2 The embodiment 1 and Figure 4 In the second embodiment shown, the two-dimensional prism group used is as follows Figure 8 As shown, the two-dimensional prism group can adopt an integrated structure, such as Figure 8 The two structures shown in (a) and (c) are as follows. In the side view, the two-dimensional prism group (a) is a roof prism, while in the top view, it is a wedge prism; in the side view, the two-dimensional prism group (c) is composed of two prisms with their thin ends aligned, while in the top view, it is a wedge prism. The two-dimensional prism group can also be composed of two one-dimensional prisms, as shown in Figure 8 The two structures shown in (b) and (d) are as follows, wherein (b) the side viewing angle of the one-dimensional prism 201 is a roof prism, and the top viewing angle is a flat glass, and the side viewing angle of the one-dimensional prism 202 is a flat glass, and the top viewing angle is a wedge prism; or (d) the side viewing angle of the one-dimensional prism 203 is two identical triangular prisms with their thin ends aligned, and the top viewing angle is a flat glass, and the side viewing angle of the one-dimensional prism 204 is a flat glass, and the top viewing angle is a wedge prism.

[0072] exist Figure 2 In the embodiment 1 shown, it can be seen that the wedge angle of the two-dimensional prism group in the x direction deflects the light beam in the xz plane, so that the incident light and the outgoing light form an angle, so that the reflector 4 is at a different height from the optical front end 1 and the optical back end 7, and the optical route of the matrix optical switch is Figure 1 The flat W-shaped shown is folded into a 3D shape. After using the two-dimensional prism group, the optical front end 1 and the optical rear end 7 are folded to be parallel to each other and can be combined into an optical front end, becoming Figure 4 In the second embodiment shown, the structure of the matrix optical switch is simpler, which can reduce the difficulty of assembly.

[0073] Figure 5 The third embodiment shown and Figure 6 In the fourth embodiment shown in FIG. 1 , the two-dimensional prism group used is as follows: Fig. 9 As shown, the two-dimensional prism group can adopt an integrated structure, such as Fig. 9 The two structures shown in (a) and (c) are both wedge-shaped prisms in the top view; in the side view, the wedge angle of the left quadrangular prism of the two-dimensional prism group (a) is larger than that of the right quadrangular prism, and the wedge angle of the left quadrangular prism of the two-dimensional prism group (c) is smaller than that of the right quadrangular prism. The two-dimensional prism group can also be composed of two one-dimensional prisms, such as Fig. 9The two structures shown in (b) and (d) are as follows, wherein the side viewing angle of the one-dimensional prism 205 in (b) is a roof prism, and the top viewing angle is a flat glass, the side viewing angle of the one-dimensional prism 206 is a wedge prism, and the top viewing angle is a wedge prism; or, the side viewing angle of the one-dimensional prism 207 is two identical prisms with their thin ends aligned, and the top viewing angle is a flat glass, the side viewing angle of the one-dimensional prism 208 is a wedge prism, and the top viewing angle is a wedge prism.

[0074] exist Figure 5 In the third embodiment shown, it can be seen that the wedge angle of the two-dimensional prism group in the x direction deflects the light beam in the xz plane, so that the incident light and the outgoing light form an angle, so that the concave reflector 4 is at a different height from the optical front end 1 and the optical back end 7, and the optical route of the matrix optical switch is Figure 1 The flat W-shaped shown is folded into a 3D shape. After using the two-dimensional prism group, the optical front end 1 and the optical rear end 7 are folded to be parallel to each other and can be combined into an optical front end, becoming Figure 6 In the fourth embodiment shown, the structure of the matrix optical switch is simpler, which can reduce the difficulty of assembly.

[0075] In the static state without any driving signal, the LCOS chip functions as a plane reflector. The 2F optical system composed of the first LCOS chip 3, the second LCOS chip 6 and the concave reflector 4 has an equivalent optical path in the static state as follows: Fig.10 As shown in the figure, the concave reflector 4 is equivalent to a lens; the spot position of the light beam incident on the second LCOS chip 6 is as shown in Fig.11 Show.

[0076] When no two-dimensional prism group is set in front of the LCOS chip, the static optical path is as follows Fig.10 As shown in (a), the light beams from all input ports are incident on the center position of the second LCOS chip 6 after being reflected by the first LCOS chip 3 and focused by the lens. Fig.11 In order to switch the beam to the edge port (upper left or upper right port), the width of the spot swept in the x direction is , the width swept in the y direction is , the maximum diffraction deflection angle in the x direction generated by the corresponding block on the first LCOS chip 3 is required to be , the maximum diffraction deflection angle in the y direction is , is the focal length of the concave reflector.

[0077] When a two-dimensional prism group is set in front of the LCOS chip ( Figure 8 In (a) or (c), due to the wedge angle function in the y direction of the two-dimensional prism group, the static optical path is as follows Fig.10As shown in (b) or (c), the two groups of light beams generated by polarization diversity are incident on the center positions of the upper and lower halves of the second LCOS chip 6 respectively after being reflected by the first LCOS chip 3 and focused by the lens. Fig.11 In order to switch the beam to the edge port, the width of the spot in the x direction is , the width swept in the y direction is , the maximum diffraction deflection angle in the x direction generated by the corresponding block on the first LCOS chip 3 is required to be , the maximum diffraction deflection angle in the y direction is .

[0078] It can be seen that after the two-dimensional prism group is set in front of the LCOS chip, the diffraction angle of the LCOS chip is The requirement is reduced, thereby increasing the diffraction efficiency and reducing the loss of the matrix optical switch. In other words, when the diffraction deflection angle of the LCOS chip is constant, this optical design can realize a matrix optical switch with more ports. When the maximum deflection angle of the LCOS is constant, Fig.10 The number of ports corresponding to the structure shown in (a) is 5×11, then Fig.10 Middle (b), Fig.10 The number of ports corresponding to the structure shown in (c) is 10×11. Fig.10 The number of ports in structure (a) has increased by 100%.

[0079] Preferably, the optical front end and the optical back end are parallel to each other and can be combined into one optical front end, thereby further reducing the size of the matrix optical switch.

[0080] Preferably, the two LCOS chips are arranged in parallel, or they can be combined into one LCOS chip to further simplify the device structure of the matrix optical switch.

[0081] Based on the above, the present application provides an optical communication device, comprising the compact matrix optical switch and a circuit control board as described above; the circuit control board is used to provide a phase control signal for the first LCOS chip and the second LCOS chip in the compact matrix optical switch.

[0082] It should be understood that expressions such as "including" and "may include" that may be used in the present application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In the present application, terms such as "including" and / or "having" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0083] In addition, in the present application, the expression "and / or" includes any and all combinations of the associated listed words. For example, the expression "A and / or B" may include A, may include B, or may include both A and B.

[0084] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Among them, "fixed connection" means that the relative position relationship after connection remains unchanged. "Rotational connection" means that the two are connected to each other and can rotate relative to each other after connection. "Sliding connection" means that the two are connected to each other and can slide relative to each other after connection. The directional terms mentioned in the embodiments of the present application, such as "top", "bottom", "inside", "outside", "left", "right", etc., are only reference directions of the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0085] In addition, in the embodiments of the present application, the mathematical concepts mentioned are symmetry, equality, parallelism, verticality, etc. These limitations are all for the current state of the art, rather than being absolutely strict definitions in a mathematical sense, and allow a small amount of deviation, approximation to symmetry, approximation to equality, approximation to parallelism, approximation to verticality, etc. are all possible. For example, A and B are parallel, which means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 and 10 degrees. A and B are perpendicular, which means that A and B are perpendicular or approximately perpendicular, and the angle between A and B can be between 80 and 100 degrees.

[0086] 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 compact matrix optical switch based on a two-dimensional prism group, characterized in that: It includes an optical front end, a first two-dimensional prism group, a first LCOS chip, a concave reflector, a second two-dimensional prism group, a second LCOS chip and an optical back end which are sequentially arranged along a three-dimensional W-shaped optical path; The first LCOS chip and the second LCOS chip are both arranged on the focal plane of the concave reflector, and the three together constitute a 2F optical system; The first two-dimensional prism group and the second two-dimensional prism group have the same structure, wherein the first two-dimensional prism group applies an additional deflection in the xz plane to two beams of mutually parallel linear polarized light after polarization diversity at each port of the optical front end through refraction on the xz plane, applies an additional deflection in the yz plane to two beams of mutually parallel linear polarized light after polarization diversity at each port of the optical front end through refraction on the yz plane, and the second two-dimensional prism group applies an additional deflection in the xz plane to the linear polarized light reflected by the concave reflector through refraction on the xz plane, so that the linear polarized light is corrected to be parallel to each other, and applies an additional deflection in the yz plane to the linear polarized light reflected by the concave reflector through refraction on the yz plane, so that the linear polarized light is parallel to the output light of the optical front end; Under the premise that no driving voltage is applied to the first LCOS chip and the second LCOS chip, two groups of parallel light beams generated by polarization diversity from each port of the optical front end are successively refracted in two dimensions by the first two-dimensional prism group, reflected by the first LCOS chip, reflected by the concave reflector, and refracted in two dimensions by the second two-dimensional prism group, and then are incident on the center positions of the upper and lower halves of the second LCOS chip respectively.

2. The compact matrix optical switch according to claim 1, characterized in that: In the compact matrix optical switch, the first two-dimensional prism group, the first LCOS chip and the concave reflector must simultaneously meet the following four conditions: in, is the number of ports in the x direction of the optical front end, is the side length of the pixel area allocated to a single port on the first LCOS chip, is the focal length of the concave reflector, is the angle between the incident light and the normal line of the incident surface of the first two-dimensional prism group in the x direction, is the angle between the outgoing light and the normal line of the outgoing surface of the first two-dimensional prism group in the x direction, is the refractive index of the first two-dimensional prism group, is the required distance between the concave reflector and the optical front end after folding, is the angle between the incident light and the normal line of the incident surface of the first two-dimensional prism group in the y direction, is the angle between the emitted light and the normal line of the emission surface of the first two-dimensional prism group in the y direction.

3. The compact matrix optical switch according to claim 2, characterized in that: The first two-dimensional prism group is an integrated structure, and its side view angle is a roof prism, and its top view angle is a wedge prism; or, its side view angle is that the thin ends of two identical triangular prisms are aligned, and its top view angle is a wedge prism.

4. The compact matrix optical switch according to claim 2, characterized in that: The first two-dimensional prism group is composed of two one-dimensional prisms, one of which has a side viewing angle of a roof prism and a top viewing angle of flat glass, and the other has a side viewing angle of flat glass and a top viewing angle of a wedge prism; or, one of which has a side viewing angle of two identical triangular prisms with their thin ends aligned and a top viewing angle of flat glass, and the other has a side viewing angle of flat glass and a top viewing angle of a wedge prism.

5. The compact matrix optical switch according to claim 2, characterized in that: The first two-dimensional prism group is an integrated structure, and its top-view angle is a wedge-shaped prism, and the side-view angle is that the thick ends of two four-prisms with different wedge angles are aligned with the thin ends.

6. The compact matrix optical switch according to claim 2, characterized in that: The first two-dimensional prism group is composed of two one-dimensional prisms, one of which has a side viewing angle of a roof prism and a top viewing angle of a flat glass, and the other has a side viewing angle of a wedge prism and a top viewing angle of a wedge prism; or, one of which has a side viewing angle of two identical triangular prisms with their thin ends aligned and a top viewing angle of a flat glass, and the other has a side viewing angle of a wedge prism and a top viewing angle of a wedge prism.

7. The compact matrix optical switch according to claim 1, characterized in that: The optical front end and the optical back end are arranged in parallel and merged into one optical front end.

8. The compact matrix optical switch according to claim 1, characterized in that: Two LCOS chips are arranged in parallel and merged into one LCOS chip.

9. The compact matrix optical switch according to claim 1, characterized in that: The maximum diffraction deflection angle in the x direction generated by the corresponding block on the first LCOS chip , maximum diffraction deflection angle in the y direction ,in, is the focal length of the concave reflector, Indicates the number of ports in the x direction of the optical front end. Indicates the number of ports in the Y direction of the optical front end. is the side length of the pixel area allocated to a single port on the first LCOS chip.

10. An optical communication device, characterized in that: A compact matrix optical switch and a circuit control board comprising any one of claims 1 to 9; The circuit control board is used to provide a phase control signal for the first LCOS chip and the second LCOS chip in the compact matrix optical switch.

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