Optical device and optical switching device

Abstract

An optical device and an optical switching device. The optical device comprises: an electrode module (30), first liquid crystal layers (31), a polarization adjustment layer (32) and a second liquid crystal layer (33), wherein the electrode module (30) is configured to apply different electric fields to two opposite edge regions (Q1, Q2) in the liquid crystal layers (31, 33); the first liquid crystal layers (31) perform first phase adjustment on first polarized light in a light beam under the action of the electric fields; the light beam further comprises second polarized light, the polarization direction of the first polarized light being perpendicular to the polarization direction of the second polarized light; the polarization adjustment layer (32) adjusts the polarization direction of the polarized light in the light beam that passes through the first liquid crystal layers (31), such that the first polarized light and the second polarized light exchange polarization directions; and the second liquid crystal layer (33) performs, under the action of the electric field, a second phase adjustment on the second polarized light in the light beam that has undergone polarization direction adjustment by passing through at least one of the first liquid crystal layers (31) and the polarization adjustment layer (32), thereby improving the performance of the optical switching device.

Description

Optical devices, optical switching equipment

[0001] This application claims priority to Chinese patent application filed on November 4, 2024, with application number 202411562231.1 and entitled "Optical Devices, Optical Switching Equipment", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of optical technology, and in particular to an optical device and an optical switching device. Background Technology

[0003] With the development of technology, optical communication networks are gradually replacing electrical communication networks due to their advantages such as low latency and low power consumption. Optical communication networks utilize optical switching equipment to exchange light beams between multiple communication devices. Examples of optical switching equipment include wavelength selective switches (WSS) and data center optical cross-connect (DC-OXC) equipment.

[0004] Optical switching equipment includes multiple optical ports and optical devices. The optical ports connect to communication equipment. The optical switching equipment uses optical devices to adjust the phase of light beams received from some optical ports, changing the beam's transmission direction and thus switching the beam to other optical ports, and ultimately to the communication equipment connected to those ports. However, optical devices often only adjust the phase of polarized light with a specific polarization direction within the beam, and cannot adjust the phase of polarized light with other polarization directions. To adjust the phase of all polarized light in the beam, the optical switching equipment typically first separates the polarized light with different polarization directions, then converts the polarization direction of other polarized light to the aforementioned specific polarization direction, and finally uses optical devices to adjust the phase of the light with the specific polarization direction.

[0005] However, because light with different polarization directions undergoes different processing in optical switching equipment, the polarization dependent loss (PDL) of optical switching equipment is relatively large. The PDL of optical switching equipment is negatively correlated with its performance; therefore, a large PDL indicates poor performance of the optical switching equipment. Summary of the Invention

[0006] This application provides an optical device and an optical switching equipment, which can solve the problem of poor performance of optical switching equipment in related technologies. The solution provided by this application is as follows.

[0007] In a first aspect, this application provides an optical device comprising: an electrode module, at least one first liquid crystal layer, a polarization adjustment layer, and at least one second liquid crystal layer.

[0008] The electrode module is used to apply different electric fields to two opposite edge regions in each of the at least one first liquid crystal layer and the at least one second liquid crystal layer, the two edge regions being arranged parallel to the polarization adjustment layer. Each of the at least one first liquid crystal layer in the optical device is used to: receive a light beam incident from the side of the first liquid crystal layer away from the polarization adjustment layer, and to perform a first phase adjustment on the first polarized light in the light beam under the action of the electric field applied by the electrode module.

[0009] A light beam incident from the side of the first liquid crystal layer away from the polarization adjustment layer includes first polarized light and second polarized light with polarization directions perpendicular to each other. The first liquid crystal layer can change the phase of the first polarized light, but cannot change the phase of the second polarized light. Therefore, the first liquid crystal layer can perform a first phase adjustment on the first polarized light in the beam, but cannot perform a phase adjustment on the second polarized light in the beam.

[0010] The polarization adjustment layer is used to adjust the polarization direction of the polarized light in the beam that has passed through at least one first liquid crystal layer, and the polarization direction adjustment causes the first polarized light and the second polarized light to interchange polarization directions.

[0011] The second liquid crystal layer is used to perform a second phase adjustment on the second polarized light in the beam whose polarization direction has been adjusted by at least one first liquid crystal layer and polarization adjustment layer under the action of the electric field applied by the electrode module.

[0012] As described above, the light beam sequentially passes through the first liquid crystal layer, the polarization adjustment layer, and the second liquid crystal layer in the optical device provided in this embodiment. When the light beam passes through the first liquid crystal layer, the first liquid crystal layer performs a first phase adjustment on the first polarized light, but cannot adjust the phase of the second polarized light. Under the action of the polarization adjustment layer, the first and second polarized lights exchange polarization directions. Therefore, when the light beam passes through the second liquid crystal layer, the second liquid crystal layer performs a second phase adjustment on the second polarized light, but cannot adjust the phase of the first polarized light. In summary, the first polarized light in the light beam undergoes phase adjustment in the first liquid crystal layer, and the second polarized light in the light beam undergoes phase adjustment in the second liquid crystal layer. In this way, the optical device can perform phase adjustment on both the first and second polarized lights in the light beam, avoiding the problem caused by the optical device only being able to perform phase adjustment on one type of polarized light in the light beam.

[0013] Furthermore, the aforementioned polarization adjustment layer can be implemented in various ways; this application uses a half-wave plate as an example. Optionally, the polarization adjustment layer can also be implemented without a half-wave plate; for example, it can be implemented using a metasurface structure. With these implementation methods, the cost of the polarization adjustment layer is relatively low, therefore, the cost of the optical device is not high.

[0014] Optionally, the total phase adjustment amount of the first phase adjustment of each first liquid crystal layer in the optical device is the same as the total phase adjustment amount of the second phase adjustment of each second liquid crystal layer. Therefore, the phase adjustment amount of the optical device for the first polarized light in the beam is the same as the phase adjustment amount of the optical device for the second polarized light in the beam. Of course, the total phase adjustment amount of the first phase adjustment of each first liquid crystal layer in the optical device can also be approximately the same as the total phase adjustment amount of the second phase adjustment of each second liquid crystal layer, for example, the difference between the two total phase adjustment amounts is 1%, 1.5%, etc.

[0015] In the above embodiments, the optical device includes at least one first liquid crystal layer and at least one second liquid crystal layer. When the optical device includes multiple first liquid crystal layers and multiple second liquid crystal layers, the multiple first liquid crystal layers and multiple second liquid crystal layers correspond one-to-one. The phase adjustment amount of the first phase adjustment of the first liquid crystal layer is the same as the phase adjustment amount of the second phase adjustment of the corresponding second liquid crystal layer.

[0016] When an optical device includes multiple first liquid crystal layers and multiple second liquid crystal layers, the number of first liquid crystal layers and the number of second liquid crystal layers can be different; when the number of first liquid crystal layers and the number of second liquid crystal layers are the same, the multiple first liquid crystal layers and the multiple second liquid crystal layers correspond one-to-one, but the phase adjustment amount of the first phase adjustment of the first liquid crystal layer and the phase adjustment amount of the corresponding second phase adjustment of the second liquid crystal layer can also be different.

[0017] In addition, the electrode module may include a transparent electrode layer superimposed on the aforementioned first liquid crystal layer, polarization conversion layer, and second liquid crystal layer. For example, the electrode module may include: at least two first transparent electrode layers and at least two second transparent electrode layers; a first liquid crystal layer is arranged between every two adjacent first transparent electrode layers, and a second liquid crystal layer is arranged between every two adjacent second transparent electrode layers; the electric field on the first liquid crystal layer is applied by the adjacent first transparent electrode layer, and the electric field on the second liquid crystal layer is applied by the adjacent second transparent electrode layer.

[0018] It is understood that the electrode module may not include the aforementioned transparent electrode layer. For example, the electrode module may include some electrodes that are attached to both sides of the film structure composed of the first liquid crystal layer, the polarization conversion layer, and the second liquid crystal layer in the direction parallel to the polarization conversion layer.

[0019] When the electrode module includes a transparent electrode layer, the polarization adjustment layer can be positioned in various ways. For example, the polarization adjustment layer 32 can be located between the at least two first transparent electrode layers and the at least two second transparent electrode layers; or, for example, the polarization adjustment layer can be located between the at least one first liquid crystal layer and the target conductive layer. The target conductive layer can be either the first transparent electrode layer closest to the second liquid crystal layer among the at least two first transparent electrode layers, or the target conductive layer can be the second transparent electrode layer closest to the first liquid crystal layer among the at least two second transparent electrode layers.

[0020] Secondly, this application provides another optical device, which includes: an electrode module, and at least one liquid crystal layer, a polarization adjustment layer and a reflective layer, wherein the polarization adjustment layer is located between the at least one liquid crystal layer and the reflective layer.

[0021] The electrode module is used to apply different electric fields to two opposite edge regions of each liquid crystal layer in at least one liquid crystal layer, the two edge regions being arranged parallel to the polarization adjustment layer.

[0022] Each of the at least one liquid crystal layer is used to: receive a light beam incident from the side of the liquid crystal layer away from the polarization adjustment layer, and perform a first phase adjustment on the first polarized light in the light beam under the action of the electric field applied by the electrode module; the light beam also includes a second polarized light, the polarization direction of the first polarized light being perpendicular to the polarization direction of the second polarized light.

[0023] The polarization adjustment layer is used to adjust the polarization direction of the polarized light in the beam that has passed through at least one liquid crystal layer.

[0024] The reflective layer is used to reflect the light beam that has passed through at least one liquid crystal layer and the polarization adjustment layer in sequence to the polarization adjustment layer;

[0025] The polarization adjustment layer is also used to perform a second polarization direction adjustment on the polarized light in the light beam that has passed through at least one liquid crystal layer, the polarization adjustment layer, and the reflective layer in sequence. The combined effect of the first and second polarization direction adjustments allows the first and second polarized light to interchange their polarization directions. Therefore, the sum of the adjustment amount for each polarized light in the first and second polarization directions in the first and second polarization directions is 90 degrees. In this way, after the first and second polarization direction adjustments, the first and second polarized light can interchange their polarization directions.

[0026] The liquid crystal layer is also used to perform a second phase adjustment on the second polarized light in the beam that has passed through at least one liquid crystal layer, a polarization adjustment layer, a reflective layer and a polarization adjustment layer in sequence, and has undergone the first polarization direction adjustment and the second polarization direction adjustment, under the action of the electric field applied by the electrode module.

[0027] As described above, the light beam sequentially passes through the liquid crystal layer, polarization adjustment layer, reflective layer, and liquid crystal layer in the optical device provided in this application embodiment. When the light beam first passes through the liquid crystal layer, the liquid crystal layer performs a first phase adjustment on the first polarized light but cannot adjust the phase of the second polarized light. Under the action of the polarization adjustment layer, both the first and second polarized lights change their polarization directions. After the reflective layer reflects these polarized lights back to the polarization adjustment layer, under the action of the polarization adjustment layer, both the first and second polarized lights change their polarization directions again, achieving an interchange of polarization directions. Therefore, when the light beam passes through the liquid crystal layer for the second time, the liquid crystal layer can perform a second phase adjustment on the second polarized light but cannot adjust the phase of the first polarized light.

[0028] In summary, the first polarized light in the beam undergoes phase adjustment within the liquid crystal layer upon its first pass, and the second polarized light undergoes phase adjustment within the same layer upon its second pass. This allows the optical device to adjust the phase of both the first and second polarized light in the beam, avoiding the problem of optical devices only being able to adjust the phase of one type of polarized light.

[0029] Optionally, the total phase adjustment amount of the first phase adjustment of each liquid crystal layer in the optical device is the same as the total phase adjustment amount of the second phase adjustment of each liquid crystal layer. Therefore, the phase adjustment amount of the optical device for the first polarized light in the beam is the same as the phase adjustment amount of the optical device for the second polarized light in the beam. Of course, the total phase adjustment amount of the first phase adjustment of each liquid crystal layer in the optical device can also be approximately the same as the total phase adjustment amount of the second phase adjustment of each liquid crystal layer, for example, the difference between the two total phase adjustment amounts is 1%, 1.5%, etc.

[0030] Furthermore, the aforementioned polarization adjustment layer can be implemented in various ways. In this embodiment, a quarter-wave plate is used as an example. Optionally, the polarization adjustment layer can also be implemented without a quarter-wave plate; for example, it can be implemented using a metasurface structure. With these implementation methods, the cost of the polarization adjustment layer is relatively low; additionally, the cost of the reflective layer is also low; therefore, the cost of the optical device is not high.

[0031] The electrode module can refer to the electrode module in the foregoing embodiments. For example, the electrode module may include transparent electrode layers. For instance, the electrode module may include: at least two transparent electrode layers; a liquid crystal layer arranged between every two adjacent transparent electrode layers; and an electric field on the liquid crystal layer is applied by the adjacent transparent electrode layers.

[0032] When the electrode module includes a transparent electrode layer, the position of the polarization adjustment layer can be varied. For example, the polarization adjustment layer 32 may be located between the electrode module and the reflective layer; or the polarization adjustment layer may be located between at least one liquid crystal layer and the target conductive layer, where the target conductive layer is the transparent electrode layer closest to the reflective layer among the at least two transparent electrode layers.

[0033] Thirdly, this application also provides an optical switching device, which includes: an optical device and a plurality of optical ports; the optical device here can be an optical device provided by any design in the first or second aspect. The optical switching device is used to perform phase adjustment of the light between the plurality of optical ports using the optical device. The optical switching device can be a wavelength selective switch (WSS) or an optical cross connect (OXC) device, etc.

[0034] The effects of the second and third aspects mentioned above can be referred to the effects of the corresponding designs in the first aspect, and will not be elaborated here. Attached Figure Description

[0035] Figure 1 is a schematic diagram of a ROADM node provided in an embodiment of this application;

[0036] Figure 2 is a schematic diagram of a short-range optical communication interconnection network for a data center provided in an embodiment of this application;

[0037] Figure 3 is a schematic diagram of the first type of optical device provided in the embodiments of this application;

[0038] Figure 4 is a schematic diagram of a WSS provided in an embodiment of this application;

[0039] Figure 5 is a schematic diagram of the effect of a wedge-shaped glass on a light beam according to an embodiment of this application;

[0040] Figure 6 is a schematic diagram of the effect of another wedge-shaped glass on a light beam according to an embodiment of this application;

[0041] Figure 7 is a schematic diagram of the second type of optical device provided in the embodiments of this application;

[0042] Figure 8 is a schematic diagram of two edge regions in a liquid crystal layer provided in an embodiment of this application;

[0043] Figure 9 is a schematic diagram of the transmission of a first polarized light in a light beam in an optical device according to an embodiment of this application;

[0044] Figure 10 is a schematic diagram of the transmission of a second polarized light in a light beam in an optical device according to an embodiment of this application;

[0045] Figure 11 is a schematic diagram of the third type of optical device provided in the embodiments of this application;

[0046] Figure 12 is a schematic diagram of a transparent electrode layer provided in an embodiment of this application;

[0047] Figure 13 is a schematic diagram of the fourth type of optical device provided in the embodiments of this application;

[0048] Figure 14 is a schematic diagram of the fifth type of optical device provided in the embodiments of this application;

[0049] Figure 15 is a schematic diagram of the sixth optical device provided in the embodiments of this application;

[0050] Figure 16 is a schematic diagram of the seventh optical device provided in the embodiments of this application;

[0051] Figure 17 is a schematic diagram of the transmission of the first polarized light in another beam provided in an embodiment of this application in an optical device;

[0052] Figure 18 is a schematic diagram of the transmission of a second polarized light in an optical device in another light beam provided in an embodiment of this application;

[0053] Figure 19 is a schematic diagram of the eighth optical device provided in the embodiments of this application. Detailed Implementation

[0054] This application provides an optical switching device, which is an important component of optical communication networks. Optical communication networks utilize optical switching devices to exchange light beams between communication devices to achieve communication between them. For example, the optical switching device provided in this application can be a WSS or OXC device (such as a data center optical cross connect (DC-OXC) device).

[0055] Currently, with the rapid growth of network traffic and bandwidth, higher demands are being placed on the performance of optical switching equipment. The following two examples will illustrate this in detail.

[0056] Example 1: In traditional long-distance optical communication networks (such as metropolitan area optical communication networks), optical switching nodes are evolving from fixed optical add / drop multiplexer (FOADM) nodes centered on arrayed waveguide gratings (AWGs) and coated filters to reconfigurable optical add-drop multiplexer (ROADM) nodes centered on WSSs. As shown in Figure 1, ROADM node 01 includes multiple interconnected WSSs 011. Each WSS 011 is connected not only to its corresponding line-side device 02 (a type of communication device), but also to its corresponding client-side device 03 (a type of communication device), as well as other WSSs 011. WSSs 011 can exchange light beams between line-side device 02, client-side device 03, and other WSSs 011.

[0057] ROADM nodes enable the network to quickly and flexibly configure wavelength-level services, improve the utilization of optical spectrum resources, and support automatic wavelength routing planning, scheduling, and maintenance. Therefore, ROADM nodes are key devices for realizing autonomous driving networks (ADN).

[0058] For ROADM nodes, higher demands are being placed on the performance and cost of the WSS (Wireless Shielding System). For example, as optical transceiver rates evolve from 100 gigabits per second (Gbps) and 200 Gbps to 400 Gbps and even higher, core performance indicators of the WSS, such as insertion loss and PDL (Programmable Logic Length), are expected to decrease by more than 50%. Furthermore, if the requirement is that ROADM nodes do not increase costs compared to FOADM nodes, this necessitates a significant reduction in the cost of the WSS.

[0059] Example 2: In a short-range optical communication interconnection network in a data center, as shown in Figure 2, a DC-OXC device 11 exchanges light beams between multiple computing units 12. The DC-OXC device 11 can adapt to scenarios where the computing power for artificial intelligence (AI) training driven by large models (machine learning models) is rapidly increasing, and the cluster size of computing units 12 is rapidly expanding. The short-range optical communication interconnection network in the data center adopts an optical switching scheme. Compared with traditional electrical switching schemes, optical switching schemes have multiple advantages, such as easier scaling up of switching capacity, low latency, low power consumption, and compatibility with multiple generations of optical module rates. In the short-range optical communication interconnection network of the data center, because the power of the switched light beams is relatively low, the link budget of the beams is low. Therefore, the DC-OXC device must have low insertion loss and low PDL. In addition, high reliability and low cost are also important development directions for DC-OXC devices.

[0060] As can be seen from the two examples above, optical switching equipment needs to have characteristics such as low insertion loss, low PDL, high reliability, and low cost.

[0061] In related technologies, optical switching equipment includes multiple optical ports and optical devices. The optical ports are connected to communication equipment. The optical switching equipment uses optical devices to adjust the phase of the light beams received from some optical ports to change the transmission direction of the light beams, thereby switching the light beams to other optical ports and then to the communication equipment connected to these optical ports.

[0062] The optical device can be a liquid crystal tunable wedge, as shown in Figure 3. This optical device includes a first indium tin oxide (ITO) conductive glass 21, a second ITO conductive glass 22, and a liquid crystal layer 23. The first ITO conductive glass 21 and the second ITO conductive glass 22 are disposed opposite each other, and the liquid crystal layer 23 is located between the first ITO conductive glass 21 and the second ITO conductive glass 22. Referring to Figure 3, each of the first ITO conductive glass 21 and the second ITO conductive glass 22 includes a glass layer 201 and two ITO electrodes 202 disposed on the side of the glass layer 201 near the liquid crystal layer 23. These two ITO electrodes 202 are located near two opposite edge regions in the liquid crystal layer 23 (the left and right edge regions in Figure 3) and are used to apply an electric field to these two edge regions. When both the first ITO conductive glass 21 and the second ITO conductive glass 22 apply an electric field to the liquid crystal layer 23, the electric fields in these two edge regions of the liquid crystal layer 23 are different, causing the liquid crystal in the liquid crystal layer 23 to deflect under the influence of these different electric fields. The deflected liquid crystal can adjust the phase of the light beam, thereby changing the direction of the beam's transmission.

[0063] For example, when both the first ITO conductive glass 21 and the second ITO conductive glass 22 apply an electric field to the liquid crystal layer 23, the electric field and voltage in the two edge regions of the liquid crystal layer 23 are different. Assume that the voltage between the ITO electrodes 202 of the first ITO conductive glass 21 and the second ITO conductive glass 22 in the left edge region of Figure 3 is denoted as V1, and the voltage between the ITO electrodes 202 of the first ITO conductive glass 21 and the second ITO conductive glass 22 in the right edge region of Figure 3 is denoted as V2. Then, when V1 is less than V2, the effect of the liquid crystal layer 23 on the light beam is equivalent to the effect of the wedge-shaped glass on the light beam shown in Figure 4. In this case, the liquid crystal layer 23 can deflect the vertically incident light beam from above to the left by a certain angle and output it from below. When V1 is greater than V2, the effect of the liquid crystal layer 23 on the light beam is equivalent to the effect of the wedge-shaped glass on the light beam shown in Figure 5. In this case, the liquid crystal layer 23 can deflect the vertically incident light beam from above to the right by a certain angle and output it from below. Furthermore, the angle at which the light beam deflects in the liquid crystal layer 23 is related to both V1 and V2. This angle can be adjusted by adjusting V1 and V2 (this angle can be adjusted continuously), thereby adjusting the transmission direction of the light beam output from the liquid crystal layer 23.

[0064] However, the liquid crystal acts on polarized light with a specific polarization direction, allowing the phase of the light beam incident on the liquid crystal layer 23 to be changed, thus enabling it to be transmitted in that specific direction. Meanwhile, the liquid crystal layer cannot change the phase of polarized light with other polarization directions in the beam, preventing the liquid crystal layer 23 from altering the transmission direction of that other polarized light.

[0065] In order to adjust the phase of all polarized light in a beam, optical switching equipment usually first separates the polarized light in the beam with different polarization directions, then converts the polarization direction of the other polarized light to the specific polarization direction mentioned above, and finally uses optical devices to adjust the phase of the light with the specific polarization direction.

[0066] For example, as shown in Figure 6, taking an optical switching device (WSS) as an example, the WSS includes multiple optical ports (not shown in Figure 6) and optical devices (as shown in Figure 3), as well as a Wollaston prism and a half-wave plate (also called a half-wave plate). The Wollaston prism separates the S-beams and P-beams from the light beams originating from the optical ports. The S-beam represents polarized light whose phase can be altered by the liquid crystal layer, while the P-beam represents polarized light whose phase cannot be altered by the liquid crystal layer. The polarization direction of the S-beam is perpendicular to that of the P-beam. After separating the S-beams and P-beams, the Wollaston prism can transmit the S-beam to the optical device shown in Figure 3, allowing the optical device to adjust the phase of the S-beam. The Wollaston prism can also transmit the separated P-beam to the half-wave plate, which alters the polarization direction of the P-beam to convert it into S-beams. The converted S-beams are then transmitted to the optical device shown in Figure 3, allowing the optical device to adjust the phase of the S-beams. In this way, the original P-light in the beam can be phase-adjusted in the liquid crystal layer of the optical device after conversion.

[0067] However, the addition of the Wollaston prism and half-wave plate increases the cost of the WSS. Furthermore, because the S-beam and P-beam have different optical paths in the aforementioned process, they undergo different processing, resulting in a significant difference in insertion loss between the two beams and a larger PDL (Programmable Length Limit) for the WSS.

[0068] In addition, the WSS shown in Figure 6 also includes a grating. Before reaching the optical device, polarized light needs to pass through the grating, which acts on the polarized light. However, due to the addition of the Wollaston prism and half-wave plate, the S-beam and P-beam in the original beam are split into two paths. To ensure that light from both paths can pass through the grating, the area of ​​the grating needs to be increased (e.g., doubled). At this point, the light from the two paths is transmitted to two different regions of the grating, as shown in Figure 6: region 1 is where the S-beam from the original beam is transmitted, and region 2 is where the S-beam converted from the P-beam from the original beam is transmitted. Increasing the area of ​​the grating also increases the cost of the WSS.

[0069] As the above analysis shows, optical devices in related technologies lead to increased costs and PDL of optical switching equipment, making it difficult to meet the requirements of low cost and low PDL for optical devices. Therefore, this application provides a new optical device that supports phase adjustment for both S-beams and P-beams, thereby avoiding the problem of increased costs and PDL of optical switching equipment caused by the inability of optical devices to perform phase adjustment for P-beams, and thus meeting the requirements of low cost and low PDL for optical devices.

[0070] For example, Figure 7 illustrates the structure of an optical device provided in an embodiment of this application. As shown in Figure 7, the optical device includes: an electrode module 30, at least one first liquid crystal layer 31, a polarization adjustment layer 32, and at least one second liquid crystal layer 33. Figure 7 uses one first liquid crystal layer 31 and one second liquid crystal layer 33 as an example. It is understood that the optical device may also include multiple first liquid crystal layers 31 and / or multiple second liquid crystal layers 33, and the number of first liquid crystal layers 31 and the number of second liquid crystal layers 33 may be the same or different.

[0071] Referring to Figure 7, the electrode module 30 is used to apply an electric field to each of at least one first liquid crystal layer 31 and at least one second liquid crystal layer 33. For example, the electrode module is used to apply different electric fields to two opposite edge regions in each liquid crystal layer, the arrangement of which is parallel to the polarization adjustment layer 32. This electric field enables the liquid crystal layer to adjust the phase of light with the target polarization direction in the beam. As shown in Figure 8, taking the first liquid crystal layer 31 as an example, the first liquid crystal layer 31 has two edge regions (regions Q1 and Q2). The electrode module can be used to apply different electric fields to regions Q1 and Q2 of the first liquid crystal layer 31 to form a liquid crystal tunable wedge.

[0072] Each first liquid crystal layer 31 in the optical device is used to: receive a light beam incident from the side of the first liquid crystal layer 31 away from the polarization adjustment layer 32, and perform a first phase adjustment on the polarized light in the light beam with a target polarization direction under the action of an electric field applied by the electrode module 30. For example, the light beam incident from the side of the first liquid crystal layer 31 away from the polarization adjustment layer 32 includes a first polarized light and a second polarized light with polarization directions perpendicular to each other. The first polarized light has the aforementioned target polarization direction, therefore, the polarization direction of the first polarized light is the target polarization direction, and the polarization direction of the second polarized light is perpendicular to the target polarization direction. Therefore, each first liquid crystal layer 31 in the optical device is used to: receive a light beam incident from the side of the first liquid crystal layer 31 away from the polarization adjustment layer 32, and perform a first phase adjustment on the first polarized light in the light beam under the action of an electric field applied by the electrode module 30.

[0073] The polarization adjustment layer 32 is used to adjust the polarization direction of polarized light in a beam that has passed through at least one first liquid crystal layer 31, thereby interchanging the polarization directions of the first polarized light and the second polarized light. Assume that before entering the polarization adjustment layer 32, the polarization direction of the first polarized light in the beam is the target polarization direction, and the polarization direction of the second polarized light in the beam is perpendicular to the target polarization direction. Then, after the beam passes through the first liquid crystal layer 31 and undergoes polarization adjustment by the polarization adjustment layer 32, the polarization direction of the first polarized light is adjusted from the target polarization direction to a direction perpendicular to the target polarization direction, and the polarization direction of the second polarized light is adjusted from a direction perpendicular to the target polarization direction to the target polarization direction. After polarization adjustment by the polarization adjustment layer 32, the second polarized light has the target polarization direction, but the first polarized light does not.

[0074] Each second liquid crystal layer 33 is used to perform a second phase adjustment on the polarized light with the target polarization direction in the beam after the polarization direction has been adjusted by at least one first liquid crystal layer 31 and polarization adjustment layer 32, under the action of the electric field applied by the electrode module 30. Since the second polarized light has the target polarization direction after the polarization direction adjustment by the polarization adjustment layer 32, but the first polarized light does not, each second liquid crystal layer 33 is used to perform a second phase adjustment on the second polarized light in the beam after the polarization direction has been adjusted by at least one first liquid crystal layer 31 and polarization adjustment layer 32, but cannot perform a second phase adjustment on the first polarized light.

[0075] As described above, the light beam sequentially passes through the first liquid crystal layer 31, the polarization adjustment layer 32, and the second liquid crystal layer 33 in the optical device. Figure 9 shows the transmission of the first polarized light in the light beam within the optical device, and Figure 10 shows the transmission of the second polarized light in the light beam within the optical device. As shown in Figures 9 and 10, when the light beam passes through the first liquid crystal layer 31, the first liquid crystal layer 31 performs a first phase adjustment on the first polarized light but cannot adjust the phase of the second polarized light. Under the action of the polarization adjustment layer 32, the first and second polarized lights exchange polarization directions. Therefore, when the light beam passes through the second liquid crystal layer 33, the second liquid crystal layer 33 performs a second phase adjustment on the second polarized light but cannot adjust the phase of the first polarized light.

[0076] In summary, the first polarized light in the beam undergoes phase adjustment in the first liquid crystal layer 31, and the second polarized light in the beam undergoes phase adjustment in the second liquid crystal layer 33. This allows the optical device to perform phase adjustment on both the first and second polarized light in the beam, avoiding the problem of an optical device only being able to adjust the phase of one type of polarized light. For example, the optical device provided in this embodiment does not require a Wollaston prism or a half-wave plate, and the grating area does not need to be increased. Therefore, it avoids the increased cost associated with configuring a Wollaston prism and a half-wave plate, as well as increasing the grating area.

[0077] Furthermore, the first and second polarized beams in the beam do not require splitting by a Wollaston prism before entering the optical device, and there is no need to adjust the polarization direction of the second polarized beam using a half-wave plate. Therefore, the first and second polarized beams in the beam follow the same optical path before entering the optical device, undergo the same processing, and have similar insertion losses. This reduces the PDL of the optical switching equipment (e.g., from 1.4 dB to 0.5 dB), thus improving the performance of the optical switching equipment.

[0078] Furthermore, since the beam is not split before entering the optical device, only one beam needs to be calibrated during the beam calibration process before using the optical device, which greatly reduces the time of the beam calibration process.

[0079] Furthermore, the polarization adjustment layer 32 can be implemented in various ways. In this embodiment, a half-wave plate is used as an example. Optionally, the polarization adjustment layer can also be implemented without a half-wave plate; for example, it can be implemented using a metasurface structure. With these implementation methods, the cost of the polarization adjustment layer 32 is relatively low, therefore, the cost of the optical device is not high.

[0080] The liquid crystals in the first liquid crystal layer 31 and the second liquid crystal layer 33 can be the same type of liquid crystal or different types of liquid crystals. However, both the first liquid crystal layer 31 and the second liquid crystal layer 33 can adjust the phase of the polarized light in the target polarization direction under the action of an electric field, so as to change the transmission direction of the polarized light in the target polarization direction.

[0081] Optionally, the total phase adjustment amount of the first phase adjustment of each first liquid crystal layer in the optical device is the same as the total phase adjustment amount of the second phase adjustment of each second liquid crystal layer. Therefore, the phase adjustment amount of the optical device for the first polarized light in the beam is the same as the phase adjustment amount of the optical device for the second polarized light in the beam. Of course, the total phase adjustment amount of the first phase adjustment of each first liquid crystal layer in the optical device can also be approximately the same as the total phase adjustment amount of the second phase adjustment of each second liquid crystal layer, for example, the difference between the two total phase adjustment amounts is 1%, 1.5%, etc.

[0082] In the above embodiments, the optical device includes at least one first liquid crystal layer 31 and at least one second liquid crystal layer 33. When the optical device includes multiple first liquid crystal layers and multiple second liquid crystal layers, the multiple first liquid crystal layers 31 and multiple second liquid crystal layers 33 can be in one-to-one correspondence. The phase adjustment amount of the first phase adjustment of the first liquid crystal layer 31 is the same as the phase adjustment amount of the second phase adjustment of the corresponding second liquid crystal layer 33. For example, as shown in Figure 11, suppose the optical device includes two first liquid crystal layers 31 and two second liquid crystal layers 33, wherein, in the direction from the first liquid crystal layer 31 to the second liquid crystal layer 33, the phase adjustment amount of the first phase adjustment of the first first liquid crystal layer 31 is A1, and the phase adjustment amount of the first phase adjustment of the second first liquid crystal layer 31 is A2; then, the first first liquid crystal layer 31 can correspond to the first second liquid crystal layer 33, and the second first liquid crystal layer 31 can correspond to the second second liquid crystal layer 33; the phase adjustment amount of the second phase adjustment of the first second liquid crystal layer 33 is A1, and the phase adjustment amount of the second phase adjustment of the second second liquid crystal layer 33 is A2 (or, the phase adjustment amount of the second phase adjustment of the first second liquid crystal layer 33 is A2, and the phase adjustment amount of the second phase adjustment of the second second liquid crystal layer 33 is A1).

[0083] When an optical device includes multiple first liquid crystal layers 31 and multiple second liquid crystal layers 33, the number of first liquid crystal layers 31 and the number of second liquid crystal layers 33 can also be different. When the multiple first liquid crystal layers 31 and the multiple second liquid crystal layers 33 correspond one-to-one, the phase adjustment amount of the first phase adjustment of the first liquid crystal layer 31 and the phase adjustment amount of the corresponding second phase adjustment of the second liquid crystal layer 33 can also be different. For example, in the aforementioned example where the optical device includes two first liquid crystal layers 31 and two second liquid crystal layers 33, the phase adjustment amount of the first phase adjustment of the first liquid crystal layer 31 is A1, and the phase adjustment amount of the first phase adjustment of the second liquid crystal layer 31 is A2; the phase adjustment amount of the second phase adjustment of the first second liquid crystal layer 33 is A3, and the phase adjustment amount of the second phase adjustment of the second second liquid crystal layer 33 is A4. Wherein, A1 + A2 = A3 + A4, and A1, A2, A3, and A4 are all different.

[0084] Additionally, the electrode module 30 may include a transparent electrode layer superimposed on the aforementioned first liquid crystal layer 31, polarization conversion layer 32, and second liquid crystal layer 33. For example, referring to FIG7 above, the electrode module 30 may include: at least two first transparent electrode layers 301 and at least two second transparent electrode layers 302; a first liquid crystal layer 31 is arranged between every two adjacent first transparent electrode layers 301, and a second liquid crystal layer 33 is arranged between every two adjacent second transparent electrode layers 302; the electric field on the first liquid crystal layer 31 is applied by the adjacent first transparent electrode layer 301, and the electric field on the second liquid crystal layer 33 is applied by the adjacent second transparent electrode layer 302. The two adjacent transparent electrode layers of each liquid crystal layer form a liquid crystal cell for accommodating the liquid crystal layer.

[0085] Referring to Figure 12, each of the at least two first transparent electrode layers 301 and at least two second transparent electrode layers 302 includes a transparent substrate D1 (such as glass) and two transparent electrodes D2 located on the side of the transparent substrate closest to each adjacent liquid crystal layer. These two transparent electrodes D2 are respectively distributed in the two edge regions of the liquid crystal layers adjacent to the transparent electrode layers, and each transparent electrode D2 is used to apply an electric field to the adjacent edge regions. The structure and material of the first transparent electrode layers 301 and the second transparent electrode layers 302 can be the same or different; this embodiment does not limit this.

[0086] It is understood that the electrode module 30 may not include the aforementioned transparent electrode layer. For example, the electrode module 30 may include electrodes attached to both sides of the film structure composed of the first liquid crystal layer 31, the polarization conversion layer 32, and the second liquid crystal layer 33 in a direction parallel to the polarization conversion layer 32. For example, the left and right sides of the film structure composed of the first liquid crystal layer 31, the polarization conversion layer 32, and the second liquid crystal layer 33.

[0087] When the electrode module 30 includes the aforementioned transparent electrode layer, the position of the polarization adjustment layer 32 can be varied. For example, as shown in FIG7, the polarization adjustment layer 32 is located between the at least two first transparent electrode layers 301 and the at least two second transparent electrode layers 302; or, for another example, the polarization adjustment layer 32 is located between the at least one first liquid crystal layer and the target conductive layer. The target conductive layer is either the first transparent electrode layer 301 closest to the second liquid crystal layer 33 (as shown in FIG13), or the target conductive layer is either the second transparent electrode layer 302 closest to the first liquid crystal layer 31 (as shown in FIG14).

[0088] The optical device in the foregoing embodiment is a transmissive optical device, in which a light beam passes through the optical device from the side where the first electrode layer is located and is transmitted to the side where the second electrode layer is located. Similar to this transmissive optical device employing the above-described polarization adjustment scheme, this application also provides a reflective optical device employing the aforementioned polarization adjustment scheme.

[0089] For example, as shown in FIG15, the optical device provided in the embodiment of this application includes: an electrode module 30, and at least one liquid crystal layer 34, a polarization adjustment layer 32 and a reflective layer 35, wherein the polarization adjustment layer 32 is located between at least one liquid crystal layer 34 and the reflective layer 35; FIG15 takes the number of liquid crystal layers 34 as one as an example, it can be understood that the number of liquid crystal layers 34 can also be greater than one, such as the number of liquid crystal layers 34 in FIG16 being two.

[0090] The electrode module 30 is used to apply different electric fields to two opposite edge regions of each liquid crystal layer 34 in at least one liquid crystal layer 34, the arrangement direction of the two edge regions being parallel to the polarization adjustment layer 32; this function of the electrode film layer 30 can be referred to: in the foregoing embodiment, the electrode module applies different electric fields to two opposite edge regions of each liquid crystal layer in at least one first liquid crystal layer and at least one second liquid crystal layer, which will not be repeated here in the embodiments of this application.

[0091] Each liquid crystal layer 34 is used to: receive a light beam incident from the side of the liquid crystal layer 34 away from the polarization adjustment layer 32, and perform a first phase adjustment on the polarized light in the target polarization direction of the light beam under the action of the electric field applied by the electrode module 30; the light beam includes a first polarized light and a second polarized light with mutually perpendicular polarization directions, the first polarized light having a target polarization direction. Therefore, each liquid crystal layer 34 is used to: receive a light beam incident from the side of the liquid crystal layer 34 away from the polarization adjustment layer 32, and perform a first phase adjustment on the first polarized light in the light beam under the action of the electric field applied by the electrode module 30. This function of the liquid crystal layer 34 can be referred to the function of the first liquid crystal layer 31 in the foregoing embodiment, and will not be repeated here.

[0092] The polarization adjustment layer 32 is used to perform a first polarization direction adjustment on the polarized light in the light beam that has passed through at least one liquid crystal layer 34; the reflective layer 35 is used to reflect the light beam that has passed through at least one liquid crystal layer 34 and the polarization adjustment layer 32 in sequence to the polarization adjustment layer 32; the polarization adjustment layer 32 is also used to perform a second polarization direction adjustment on the polarized light in the light beam that has passed through at least one liquid crystal layer 34, the polarization adjustment layer 32 and the reflective layer 32 in sequence.

[0093] The function of the polarization adjustment layer 32 can be found in the previous embodiment, which adjusts the polarization direction of the polarized light in the beam that has passed through at least one liquid crystal layer. This embodiment will not be described in detail here.

[0094] The sum of the adjustment amounts in the first and second polarization adjustments for each of the first and second polarization beams is 90 degrees. Thus, after the first and second polarization adjustments, the first and second polarization beams can interchange their polarization directions. It is evident that the combined effect of the first and second polarization adjustments enables the first and second polarization beams to interchange their polarization directions.

[0095] Each liquid crystal layer 34 is also used to perform a second phase adjustment on the polarized light with the target polarization direction in a light beam that has passed through at least one liquid crystal layer 34, polarization adjustment layer 32, reflective layer 35, and polarization adjustment layer 32 in sequence, and has undergone first polarization direction adjustment and second polarization direction adjustment, under the action of the electric field applied by the electrode module 30. Since the first polarized light and the second polarized light interchange polarization directions at this time, each liquid crystal layer 34 is used to perform a second phase adjustment on the second polarized light in a light beam that has passed through at least one liquid crystal layer 34, polarization adjustment layer 32, reflective layer 35, and polarization adjustment layer 32 in sequence, under the action of the electric field applied by the electrode module 30. This function of the liquid crystal layer 34 can be referred to the function of the second liquid crystal layer 33 in the foregoing embodiment, and will not be repeated here.

[0096] As described above, the light beam sequentially passes through the liquid crystal layer 34, polarization adjustment layer 32, reflective layer 35, and liquid crystal layer 34 in the optical device provided in this application embodiment. Taking the optical device shown in Figure 15 as an example, Figure 17 shows the transmission of the first polarized light in the light beam within the optical device, and Figure 18 shows the transmission of the second polarized light in the light beam within the optical device. As shown in Figures 17 and 18, when the light beam passes through the liquid crystal layer 34 for the first time, the liquid crystal layer 34 performs a first phase adjustment on the first polarized light but cannot adjust the phase of the second polarized light. Under the action of the polarization adjustment layer 32, both the first and second polarized lights change their polarization directions. After the reflective layer 35 reflects these polarized lights back to the polarization adjustment layer 32, under the action of the polarization adjustment layer 32, both the first and second polarized lights change their polarization directions again, achieving the interchange of the polarization directions of the first and second polarized lights. Therefore, when the light beam passes through the liquid crystal layer 34 for the second time, the liquid crystal layer 34 performs a second phase adjustment on the second polarized light but cannot adjust the phase of the first polarized light.

[0097] In summary, the first polarized light in the beam undergoes phase adjustment within the liquid crystal layer 34 upon its first pass, and the second polarized light undergoes phase adjustment within the liquid crystal layer 34 upon its second pass. This allows the optical device to perform phase adjustment on both the first and second polarized light in the beam, avoiding the problem of optical devices only being able to adjust the phase of one type of polarized light. For example, the optical device provided in this embodiment does not require a Wollaston prism or a half-wave plate, and the grating area does not need to be increased. Therefore, it avoids the increased cost associated with configuring a Wollaston prism and a half-wave plate, as well as increasing the grating area.

[0098] Furthermore, the first and second polarized beams in the beam do not require splitting by a Wollaston prism before entering the optical device, and there is no need to adjust the polarization direction of the second polarized beam using a half-wave plate. Therefore, the first and second polarized beams in the beam follow the same optical path before entering the optical device, and undergo the same processing, reducing the PDL of the optical switching equipment (e.g., from 1.4 dB to 0.5 dB) and improving the performance of the optical switching equipment. Moreover, since the beam is not split before entering the optical device, only one beam needs to be calibrated during the beam calibration process before using the optical device, significantly reducing the calibration time.

[0099] Optionally, the total phase adjustment amount of the first phase adjustment of each liquid crystal layer in the optical device is the same as the total phase adjustment amount of the second phase adjustment of each liquid crystal layer. Therefore, the phase adjustment amount of the optical device for the first polarized light in the beam is the same as the phase adjustment amount of the optical device for the second polarized light in the beam. Of course, the total phase adjustment amount of the first phase adjustment of each liquid crystal layer in the optical device can also be approximately the same as the total phase adjustment amount of the second phase adjustment of each liquid crystal layer, for example, the difference between the two total phase adjustment amounts is 1%, 1.5%, etc.

[0100] Furthermore, the polarization adjustment layer 32 can be implemented in various ways. In this embodiment, a quarter-wave plate is used as an example. Optionally, the polarization adjustment layer can also be implemented without a quarter-wave plate; for example, it can be implemented using a metasurface structure. With these implementation methods, the cost of the polarization adjustment layer 32 is relatively low; in addition, the cost of the reflective layer 35 is also low; therefore, the cost of the optical device is not high.

[0101] The electrode module 30 can refer to the electrode module in the foregoing embodiments. For example, the electrode module 30 may include a transparent electrode layer superimposed on the aforementioned liquid crystal layer 34, polarization conversion layer 32, and reflective layer 35. Referring to FIG15, the electrode module 30 may include: at least two transparent electrode layers 303; a liquid crystal layer 34 is arranged between every two adjacent transparent electrode layers 303; the electric field on the liquid crystal layer 34 is applied by the adjacent transparent electrode layers 303. Each of the at least two transparent electrode layers 303 can refer to the aforementioned first transparent electrode layer or second transparent electrode layer, which will not be described in detail in the embodiments of this application.

[0102] It is understood that the electrode module 30 may not include the aforementioned transparent electrode layer. For example, the electrode module 30 may include some electrodes that are attached to both sides of the film structure composed of the liquid crystal layer 34, the polarization conversion layer 32 and the reflective layer 35 in a direction parallel to the polarization conversion layer 32.

[0103] When the electrode module 30 includes a transparent electrode layer, the polarization adjustment layer 32 can be positioned in various ways. For example, as shown in FIG15, the polarization adjustment layer 32 is located between the electrode module 30 and the reflective layer 35; or, as shown in FIG19, the polarization adjustment layer 32 is located between at least one liquid crystal layer 34 and the target conductive layer, wherein the target conductive layer is the transparent electrode layer 303 closest to the reflective layer 35 among the at least two transparent electrode layers 303.

[0104] This application also provides an optical switching device, which includes an optical device and multiple optical ports. The optical device can be any type of optical device provided in this application, such as the one shown in Figure 7 or Figure 15. The optical switching device is used to perform phase adjustment of the light between the multiple optical ports using the optical device. The optical switching device can be a WSS or OXC device, etc.

[0105] In this application, the terms "first" and "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "at least one" refers to one or more, and "multiple" refers to two or more, unless otherwise expressly defined. The term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Furthermore, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0106] The different embodiments provided in this application can be referenced to each other, and this application does not limit them.

[0107] The above description is merely an embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An optical device, characterized in that, include: An electrode module, at least one first liquid crystal layer, a polarization adjustment layer, and at least one second liquid crystal layer, wherein the polarization adjustment layer is located between the at least one first liquid crystal layer and the at least one second liquid crystal layer; The electrode module is used to apply different electric fields to two opposite edge regions in each of the at least one first liquid crystal layer and the at least one second liquid crystal layer, wherein the arrangement direction of the two edge regions is parallel to the polarization adjustment layer. Each of the first liquid crystal layers is used to receive a light beam incident from the side of the first liquid crystal layer away from the polarization adjustment layer, and to perform a first phase adjustment on the first polarized light in the light beam under the action of the electric field applied by the electrode module; the light beam also includes a second polarized light, wherein the polarization direction of the first polarized light is perpendicular to the polarization direction of the second polarized light; The polarization adjustment layer is used to adjust the polarization direction of the polarized light in the light beam that has passed through the at least one first liquid crystal layer, and the polarization direction adjustment causes the first polarized light and the second polarized light to interchange polarization directions. The second liquid crystal layer is used to perform a second phase adjustment on the second polarized light in the beam after the polarization direction has been adjusted by the at least one first liquid crystal layer and the polarization adjustment layer, under the action of the electric field applied by the electrode module.

2. The optical device according to claim 1, characterized in that, The polarization adjustment layer is a half-wave plate.

3. The optical device according to claim 1 or 2, characterized in that, The total phase adjustment amount of the first phase adjustment of the at least one first liquid crystal layer is the same as the total phase adjustment amount of the second phase adjustment of the at least one second liquid crystal layer.

4. The optical device according to claim 3, characterized in that, The optical device includes: a plurality of first liquid crystal layers and a plurality of second liquid crystal layers; Each of the first liquid crystal layers corresponds one-to-one with a plurality of second liquid crystal layers, and the phase adjustment amount of the first phase adjustment of the first liquid crystal layer is the same as the phase adjustment amount of the second phase adjustment of the corresponding second liquid crystal layer.

5. The optical device according to any one of claims 1 to 4, characterized in that, The electrode module includes: at least two first transparent electrode layers and at least two second transparent electrode layers; A first liquid crystal layer is arranged between every two adjacent first transparent electrode layers, and a second liquid crystal layer is arranged between every two adjacent second transparent electrode layers. The electric field on the first liquid crystal layer is applied by the adjacent first transparent electrode layer, and the electric field on the second liquid crystal layer is applied by the adjacent second transparent electrode layer.

6. The optical device according to claim 5, characterized in that, The polarization adjustment layer is located between the at least two first transparent electrode layers and the at least two second transparent electrode layers; or, the polarization adjustment layer is located between the at least one first liquid crystal layer and the target conductive layer. The target conductive layer is either the first transparent electrode layer closest to the second liquid crystal layer among the at least two first transparent electrode layers, or the target conductive layer is the second transparent electrode layer closest to the first liquid crystal layer among the at least two second transparent electrode layers.

7. An optical device, characterized in that, include: An electrode module, and at least one liquid crystal layer, a polarization adjustment layer and a reflective layer, wherein the polarization adjustment layer is located between the at least one liquid crystal layer and the reflective layer; The electrode module is used to apply different electric fields to two opposite edge regions of each liquid crystal layer in the at least one liquid crystal layer, and the arrangement direction of the two edge regions is parallel to the polarization adjustment layer. The liquid crystal layer is used to receive a light beam incident from the side of the liquid crystal layer away from the polarization adjustment layer, and to perform a first phase adjustment on the first polarized light in the light beam under the action of the electric field applied by the electrode module; the light beam also includes a second polarized light, wherein the polarization direction of the first polarized light is perpendicular to the polarization direction of the second polarized light; The polarization adjustment layer is used to adjust the polarization direction of the polarized light in the light beam that has passed through the at least one liquid crystal layer; The reflective layer is used to reflect the light beam that passes sequentially through the at least one liquid crystal layer and the polarization adjustment layer back to the polarization adjustment layer; The polarization adjustment layer is also used to perform a second polarization direction adjustment on the polarized light in the light beam that passes through the at least one liquid crystal layer, the polarization adjustment layer and the reflective layer in sequence; the combined effect of the first polarization direction adjustment and the second polarization direction adjustment causes the first polarized light and the second polarized light to interchange polarization directions; The liquid crystal layer is also used to perform a second phase adjustment on the second polarized light in the beam that has passed through the at least one liquid crystal layer, the polarization adjustment layer, the reflection layer and the polarization adjustment layer in sequence, and has undergone the first polarization direction adjustment and the second polarization direction adjustment, under the action of the electric field applied by the electrode module.

8. The optical device according to claim 7, characterized in that, The polarization adjustment layer is a quarter-wave plate.

9. The optical device according to claim 7 or 8, characterized in that, The total phase adjustment amount of the first phase adjustment of the at least one liquid crystal layer is the same as the total phase adjustment amount of the second phase adjustment of the at least one liquid crystal layer.

10. The optical device according to any one of claims 7 to 9, characterized in that, The electrode module includes at least two transparent electrode layers; A liquid crystal layer is arranged between every two adjacent transparent electrode layers, and the electric field on the liquid crystal layer is applied by the adjacent transparent electrode layers.

11. The optical device according to claim 10, characterized in that, The polarization adjustment layer is located between the electrode module and the reflective layer, or the polarization adjustment layer is located between the at least one liquid crystal layer and the target conductive layer; The target conductive layer is the transparent electrode layer closest to the reflective layer among the at least two transparent electrode layers.

12. An optical switching device, characterized in that, The optical switching equipment includes: optical devices and multiple optical ports; The optical device is the optical device according to any one of claims 1 to 6, or the optical device is the optical device according to any one of claims 7 to 11; The optical switching device is used to perform phase adjustment of the light between the plurality of optical ports using the optical devices.

13. The optical switching device according to claim 12, characterized in that, The optical switching device is a wavelength selective switch (WSS) or an optical interconnect (OXC) device.

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