Driving method of silicon-based liquid crystal, silicon-based liquid crystal, and wavelength selective switch

Abstract

This application provides a driving method for a silicon-based liquid crystal, a silicon-based liquid crystal, and a wavelength selective switch, relating to the field of optical switching engine technology. This driving method for the silicon-based liquid crystal can reduce the risk of instantaneous excessive power while shortening the switching time. The driving method includes: dividing the area of ​​the silicon-based liquid crystal that receives a single-wavelength optical signal into M sub-regions, where M is a positive integer greater than or equal to 2, and each sub-region includes at least one row of pixels; sequentially refreshing the M sub-regions to form a first grating pattern, wherein at least two sub-regions have different overshoot power outputs of optical signals based on the first grating pattern; sequentially refreshing the M sub-regions to form a second grating pattern, the second grating pattern being determined by the output angle of the single-wavelength optical signal and the steady-state power of the single-wavelength optical signal; the difference between the overshoot power and the steady-state power of the single-wavelength optical signal output from the area covered by the light spot is less than a preset value.

Description

Technical Field

[0001] This application relates to the field of optical switching engine technology, and in particular to a driving method for a silicon-based liquid crystal, a silicon-based liquid crystal, and a wavelength selective switch. Background Technology

[0002] Optical networks are the mainstream communication networks today. Optical networks are equipped with optical switching equipment to achieve end-to-end optical signal transmission. Commonly used optical switching equipment includes optical cross-connects (OXCs) and optical add-drop multiplexers (OADMs). If a transmission path between the two ends fails, the optical network will adjust the optical switching equipment to switch the optical signals transmitted between the two ends to another transmission path, thus achieving service protection switching functionality.

[0003] To achieve seamless service protection switching for customers, the end-to-end switching time needs to be less than 50 milliseconds (ms). However, optical switching equipment includes wavelength selective switches, whose switching engine is liquid crystal on silicon (LCoS). The switching speed of LCoS is relatively slow, resulting in a switching time of 1 second for the wavelength selective switches, making it difficult to achieve seamless service protection switching for customers. Summary of the Invention

[0004] The embodiments of this application provide a driving method for a silicon-based liquid crystal, a silicon-based liquid crystal, and a wavelength selective switch. The driving method for the silicon-based liquid crystal can reduce the risk of instantaneous excessive power while shortening the switching time.

[0005] In a first aspect, a driving method for a silicon-based liquid crystal is provided, comprising: dividing a light spot coverage area into M sub-regions, wherein the light spot coverage area is a region of the silicon-based liquid crystal receiving a single-wavelength light signal, and the light spot coverage area includes N rows of pixels; M and N are positive integers greater than or equal to 2, each sub-region includes at least 1 row of pixels, and the sum of the number of pixel rows included in the M sub-regions is N; sequentially refreshing the M sub-regions to form a first grating pattern, wherein at least two sub-regions have different overshoot power of the light signal output based on the first grating pattern; sequentially refreshing the M sub-regions to form a second grating pattern, wherein the second grating pattern is determined by the output angle of the single-wavelength light signal and the steady-state light power of the single-wavelength light signal; wherein the difference between the overshoot power of the single-wavelength light signal output by the light spot coverage area and the steady-state light power of the single-wavelength light signal is less than a preset value. In this driving method for a silicon-based liquid crystal, M sub-regions are sequentially refreshed to form a first grating pattern, and at least two sub-regions have different overshoot power of the optical signal output based on the first grating pattern. Then, M sub-regions are sequentially refreshed to form a second grating pattern, which is determined by the output angle and steady-state power of the single-wavelength optical signal. A preset value is determined based on the difference between the maximum acceptable optical power of the optical network containing the silicon-based liquid crystal and the steady-state power of the single-wavelength optical signal. By adjusting the first grating pattern, the overshoot power of the optical signal output by at least two sub-regions based on the first grating pattern is made different, thereby ensuring that the difference between the overshoot power and the steady-state power of the single-wavelength optical signal output from the light spot coverage area is less than the preset value. This shortens the switching time of the silicon-based liquid crystal while also considering the instantaneous maximum optical power of the single-wavelength optical signal output by the silicon-based liquid crystal, reducing the risk of excessively high instantaneous power in the single-wavelength optical signal output by the silicon-based liquid crystal.

[0006] Optionally, before sequentially refreshing the M sub-regions to form the first grating pattern, the method further includes: determining the overshoot power of the optical signals output by the M sub-regions based on the M optical power overshoots corresponding to the M sub-regions, where the optical power overshoot is the difference between the overshoot power of the optical signals output by the sub-regions and the steady-state optical power of the optical signals output by the sub-regions, and at least two of these optical power overshoots are different; and determining the first grating pattern based on the overshoot power of the optical signals output by the M sub-regions. In this optional method, at least two optical power overshoots are different, so that the overshoot power of the optical signals output by at least two sub-regions is different.

[0007] Optionally, the overshoot power of the optical signal output from at least one sub-region is greater than the steady-state power of the optical signal output from the sub-region. In this optional configuration, the overshoot power of the optical signal output from at least one sub-region being greater than the steady-state power of the optical signal output from that sub-region indicates that the optical power overshoot corresponding to that sub-region is positive, which can shorten the switching time of the silicon-based liquid crystal.

[0008] Optionally, the overshoot power of the optical signal output from at least one sub-region is less than the steady-state power of the optical signal output from the sub-region. In this optional configuration, the overshoot power of the optical signal output from at least one sub-region being less than the steady-state power of the optical signal output from the sub-region indicates that the optical power overshoot corresponding to that sub-region is negative. This can reduce the difference between the overshoot power and the steady-state power of the single-wavelength optical signal output from the area covered by the light spot.

[0009] Optionally, the overshoot power of the optical signals output from the M sub-regions gradually decreases; or, the variation of the overshoot power of the optical signals output from the M sub-regions conforms to a Gaussian distribution.

[0010] Optionally, the overshoot power of the optical signal output from the first sub-region in the M sub-regions is greater than the steady-state power of the optical signal output from the first sub-region.

[0011] Optionally, the overshoot power of the optical signal output from the Mth sub-region is less than the steady-state power of the optical signal output from the Mth sub-region.

[0012] Optionally, the driving method of silicon-based liquid crystal is applied to silicon-based liquid crystal in a wavelength selective switch; before dividing the light spot coverage area into M sub-regions, it also includes: receiving a switching command, the switching command including a single-wavelength optical signal, a target output port in the wavelength selective switch and an optical power attenuation amount, the target output port being used to indicate the output angle of the single-wavelength optical signal, and the optical power attenuation amount being used to indicate the steady-state optical power of the single-wavelength optical signal.

[0013] Secondly, a driving method for a silicon-based liquid crystal is provided, comprising: dividing a light spot coverage area into M sub-regions, wherein the light spot coverage area is the region where the silicon-based liquid crystal receives a single-wavelength light signal, and the light spot coverage area includes N rows of pixels; M and N are positive integers greater than or equal to 2, each sub-region includes at least one row of pixels, and the sum of the number of pixel rows in the M sub-regions is N; outputting M grating patterns to the M sub-regions respectively; wherein the output angles of the light signals output by the M sub-regions are different. In this driving method for a silicon-based liquid crystal, since the output angles of the light signals output by the M sub-regions are different, the M sub-regions can divide the single-wavelength light signal O11 incident on the light spot coverage area into M parts, and output the M parts to different positions respectively. When this driving method for a silicon-based liquid crystal is applied to a silicon-based liquid crystal in a wavelength selective switch, the wavelength selective switch can realize a beam splitting monitoring function or a multi-port broadcast function.

[0014] Optionally, the driving method for silicon-based liquid crystals is applied to silicon-based liquid crystals in wavelength selective switches; before dividing the light spot coverage area into M sub-regions, it further includes: receiving a beam splitting command, the beam splitting command including a single-wavelength optical signal, transmitting the single-wavelength optical signal to M output ports respectively, and the optical power attenuation amount corresponding to each of the M output ports; one of the M grating patterns is determined by the grating period corresponding to an output port and the optical power attenuation amount corresponding to that output port.

[0015] Thirdly, a silicon-based liquid crystal is provided, the silicon-based liquid crystal including a driving circuit and a liquid crystal layer stacked together; the driving circuit is used to execute the driving method of the silicon-based liquid crystal according to any one of the first aspects, so that a first grating pattern and a second grating pattern are formed in the liquid crystal layer in the area covered by the light spot.

[0016] The technical effects of any possible implementation in the third aspect can be seen in the technical effects of different implementations in the first aspect mentioned above, and will not be repeated here.

[0017] Fourthly, a silicon-based liquid crystal is provided, the silicon-based liquid crystal including a driving circuit and a liquid crystal layer stacked together; the driving circuit is used to execute the driving method of the silicon-based liquid crystal according to any one of the second aspects above, so that M sub-regions in the light spot coverage area of ​​the liquid crystal layer form M grating patterns.

[0018] The technical effects of any possible implementation in the fourth aspect can be seen in the technical effects of different implementations in the second aspect above, and will not be repeated here.

[0019] Fifthly, a wavelength selective switch is provided, comprising a multiplexer / demultiplexer and a silicon-based liquid crystal as described in the third or fourth aspect; the multiplexer / demultiplexer is used to receive optical signals and output single-wavelength optical signals to the silicon-based liquid crystal; the silicon-based liquid crystal is used to output the single-wavelength optical signals to any port of the wavelength selective switch.

[0020] In a sixth aspect, an optical switching device is provided, comprising a plurality of wavelength selection switches as described in the fifth aspect above.

[0021] In a seventh aspect, an optical network is provided, which includes a plurality of optical switching devices as described in the sixth aspect above, the plurality of optical switching devices being connected by optical fibers.

[0022] Eighthly, a computer-readable storage medium is provided, which stores a computer program or instructions that, when executed on a computer, cause the computer to perform a driving method for a silicon-based liquid crystal as described in the first or second aspect above.

[0023] Ninthly, a computer program product is provided, which, when run on a computer, enables the computer to execute the driving method of the silicon-based liquid crystal as described in either the first or second aspect.

[0024] The technical effects of any of the possible implementations of aspects five through nine can be found in the technical effects of different implementations of aspects one or two above, and will not be repeated here. Attached Figure Description

[0025] Figure 1 A schematic diagram of the structure of an optical network provided for an embodiment of this application;

[0026] Figure 2 A schematic diagram of the structure of an optical switching device provided in an embodiment of this application;

[0027] Figure 3 A schematic diagram of the structure of a wavelength selective switch provided in an embodiment of this application;

[0028] Figure 4 A schematic diagram of the structure of a silicon-based liquid crystal provided for an embodiment of this application;

[0029] Figure 5 A graph showing the phase change of the pixel row over time, provided in this application;

[0030] Figure 6 A flowchart of the driving method for silicon-based liquid crystal provided in this application;

[0031] Figure 7 A graph showing the change in optical power of the optical signal output by the silicon-based liquid crystal provided in this application over time;

[0032] Figure 8 A flowchart of a silicon-based liquid crystal driving method provided for embodiments of this application;

[0033] Figure 9 A schematic diagram of the light-receiving surface of a silicon-based liquid crystal and a graph showing the change in optical power of the optical signal output by the silicon-based liquid crystal over time, provided for embodiments of this application;

[0034] Figure 10 A flowchart of a silicon-based liquid crystal driving method provided in another embodiment of this application;

[0035] Figure 11 A schematic diagram of the light-receiving surface of a silicon-based liquid crystal provided in another embodiment of this application. Detailed Implementation

[0036] The technical solutions in the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0037] Unless otherwise defined, all technical terms used herein have the same meaning as those known to one of ordinary skill in the art. In the embodiments of this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, a and b, a and c, b and c, or a, b, and c, where a, b, and c can be single or multiple. In addition, in the embodiments of this application, the words "first," "second," etc., do not limit the quantity or order.

[0038] Furthermore, in the embodiments of this application, directional terms such as "upper" and "lower" are defined relative to the orientation in which the components are schematically placed in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation in which the components are placed in the accompanying drawings.

[0039] In the embodiments of this application, the words "exemplary" or "for example" are used to indicate that they are examples, illustrations, or descriptions. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design options. Specifically, the use of the words "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0040] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0041] Optical networks are currently the mainstream communication networks, referencing Figure 1 As shown in the figure, an embodiment of this application provides a schematic diagram of the structure of an optical network 10, which includes a network station 11 and a network station 12, and the network station 11 and the network station 12 are connected by an optical transmission link.

[0042] Network site 11 includes an optical transform unit (OTU) and a wavelength selective switch (WSS). Figure 1 The network station 11 shown includes OTU1, OTU2, wavelength selection switch 1 and wavelength selection switch 2. OUT1 outputs a single-wavelength optical signal O11 that conforms to the transmission standard, and OUT2 outputs a single-wavelength optical signal O12 that conforms to the transmission standard. The wavelengths of the optical signals output by OUT1 and OTU2 are different. Wavelength selection switch 1 combines optical signal O11 and optical signal O12 and outputs optical signal O1 to wavelength selection switch 2. Wavelength selection switch 2 transmits optical signal O1 to network station 12 through an optical transmission link.

[0043] The optical transmission link includes optical fiber, and optical switching equipment 1 and optical switching equipment 2 deployed along the optical fiber. The optical transmission link also includes multiple optical amplifiers (OAs) deployed along the optical fiber, such as... Figure 1 The OA1, OA2, OA3, OA4, OA5 and OA6 shown are multiple OAs deployed along the optical fiber to amplify the optical signal transmitted in the optical fiber in multiple stages. Figure 1 The optical switching equipment shown includes an optical cross-connect (OXC) and an optical add-drop multiplexer (OADM). The optical transmission link between the output of optical switching equipment 1 and the input of optical switching equipment 2 is an optical multiplex section (OMS). The optical signal O1 output from network station 11 typically needs to be transmitted to network station 12 through multiple OMS sections. The optical transmission link between two adjacent OAs in an OMS is an optical transmission section (OTS). Specifically, the section between OA2 and OA3 is the first OTS, and the section between OA4 and OA5 is the second OTS.

[0044] Network station 12 includes OUT3, OTU4, wavelength selection switch 3, and wavelength selection switch 4. Wavelength selection switch 3 transmits optical signal O1 from multiple received optical signals to wavelength selection switch 4. Wavelength selection switch 4 transmits a single-wavelength optical signal O11 from optical signal O1 to OTU3, and a single-wavelength optical signal O12 from optical signal O1 to OTU4. ​​OTU3 demultiplexes the received single-wavelength optical signal O11 and outputs it, while OTU4 demultiplexes the received single-wavelength optical signal O12 and outputs it. The area between the input of OTU2 and the output of OTU4 is the optical channel layer (OCH).

[0045] For example, in the event of a fiber break at the first OTS between OA2 and OA3, the optical network 10 will control the optical switching device 1 to transmit the optical signal O1 to the optical switching device 3, and then transmit the optical signal O1 to the optical switching device 2 through the second OTS between OA4 and OA5 and the optical switching device 4, so as to realize the service protection switching function.

[0046] Before service protection switching, optical switch 1 outputs the optical signal O1 received through port a through port b, and optical switch 2 outputs the optical signal O1 received through port d through port e. After service protection switching, optical switch 1 outputs the optical signal O1 received through port a through port c, and optical switch 2 outputs the optical signal O1 received through port g through port e. Triggering service protection switching requires optical switch 1's output port to switch from port b to port c, optical switches 3 and 4 to their corresponding ports, and optical switch 2's input port to switch from port d to port g.

[0047] For example, refer to Figure 2 As shown in the diagram, an embodiment of this application provides a structural schematic of an optical switching device. The optical switching device includes multiple receiving wavelength selection switches and multiple transmitting wavelength selection switches. One receiving wavelength selection switch and one transmitting wavelength selection switch are provided in each transmission direction. The branch ports of the receiving wavelength selection switches are connected to the branch ports of the transmitting wavelength selection switches. (Refer to...) Figure 2 As shown, the multiple receiving wavelength selection switches include wavelength selection switch 5, and the multiple transmitting wavelength selection switches include wavelength selection switch 6 and wavelength selection switch 7. Among them, Figure 2 Each wavelength selection switch shown includes a common port (com) and multiple branch ports (e.g., ...). Figure 2As shown in the branch ports f1 and f2, the optical signal received by the common port com of the wavelength selection switch can be output from either branch port of the wavelength selection switch, and the optical signal received by either branch port of the wavelength selection switch can be output from the common port com of the wavelength selection switch, so as to realize the function of the optical switching equipment to transmit an optical signal of any wavelength from one transmission direction to another.

[0048] For example, when the optical switching equipment is OADM, the wavelength selection switch at the receiving end and the wavelength selection switch at the transmitting end can be directly connected via optical fiber; when the optical switching equipment 20 is OXC, the wavelength selection switch at the receiving end and the wavelength selection switch at the transmitting end can be connected via an optical backplane (also called an all-optical backplane).

[0049] exist Figure 2 The optical switching equipment shown is Figure 1 In the case of the optical switching device 1 shown, Figure 2 The common port of the wavelength selection switch 5 shown is Figure 1 Port a of optical switching device 1 in the middle, Figure 2 The common port com of the wavelength selection switch 6 shown is... Figure 1 Port b of optical switching device 1 in the middle, Figure 2 The common port com of the wavelength selection switch 7 shown is... Figure 1 Port c of optical switching equipment 1 in the system. To trigger service protection switching, wavelength selection switch 5 needs to switch from branch port f1 to branch port f2, and control wavelength selection switch 7 to connect branch port f1 to the common port com.

[0050] Reference Figure 3 As shown in the diagram, an embodiment of this application provides a structural schematic of a wavelength selective switch 5, wherein, in Figure 3 In the wavelength selection switch 5 shown, the z-axis direction is the transmission direction of the optical signal in the wavelength selection switch 5, the y-axis direction is the port arrangement direction of the wavelength selection switch 5, and the x-axis direction is the dispersion direction of the wavelength selection switch 5. Figure 3 The wavelength selection switch 5 shown includes branch port f1, branch port f2, and common port com. The plane formed by the y-axis and z-axis is the port plane of the wavelength selection switch 5. Figure 3 (a) is a schematic diagram of the port plane of wavelength selective switch 5; the plane formed by the x-axis and z-axis is the dispersion plane of wavelength selective switch 5. Figure 3(b) is a schematic diagram of the dispersion plane of the wavelength selective switch 5. The wavelength selective switch 5 includes a multiplexer / demultiplexer 21 and a liquid crystal on silicon (LCOS) 22. The multiplexer / demultiplexer 21, also called a dispersion element, has a beam splitting direction parallel to the x-axis. The liquid crystal on silicon 22 is also referred to as a switching engine.

[0051] exist Figure 3 In this configuration, the multiplexer / demultiplexer 21 receives the optical signal input from the common port com of the wavelength selection switch 5 and outputs a single-wavelength optical signal to the silicon-based liquid crystal 22; the silicon-based liquid crystal 22 transmits the single-wavelength optical signal to any branch port f1 of the wavelength selection switch 5. Alternatively, the multiplexer / demultiplexer 21 receives the optical signal input from any branch port of the wavelength selection switch 5 and outputs a single-wavelength optical signal to the silicon-based liquid crystal 22; the silicon-based liquid crystal 22 transmits the single-wavelength optical signal to the common port com of the wavelength selection switch 5.

[0052] Specifically, in Figure 3 In the process, before the service protection switchover, the multiplexer / demultiplexer 21 is used to receive the optical signal O1 input from the common port com of the wavelength selection switch 5 and output a single-wavelength optical signal O11 to the silicon liquid crystal 22; the silicon liquid crystal 22 is used to transmit the single-wavelength optical signal O11 to the branch port f1 of the wavelength selection switch 5.

[0053] For example, such as Figure 3 As shown, the wavelength selection switch 5 also includes a lens 23 disposed between the multiplexer / demultiplexer 21 and the silicon-based liquid crystal 22. The lens plane of the lens 23 is parallel to the dispersion plane. The lens 23 is used to collimate the multiple single-wavelength optical signals output by the multiplexer / demultiplexer 21 in the x-axis direction.

[0054] For example, such as Figure 3 As shown, the wavelength selection switch 5 also includes a lens 24 disposed between the silicon liquid crystal 22 and the common port com. The lens plane of the lens 24 is parallel to the port plane. The lens 24 is used to collimate the multiple single-wavelength optical signals output by the silicon liquid crystal 22 along the y-axis direction.

[0055] For example, in Figure 3 In the image, the focal length of lens 23 is FL2, the focal length of lens 24 is FL1, the right focal plane of liquid crystal on silicon 22 overlaps with that of lens 23, and the right focal plane of liquid crystal on silicon 22 overlaps with that of lens 24.

[0056] For example, such as Figure 4 As shown, Figure 4 (a) shows a three-dimensional structural diagram of the silicon-based liquid crystal 22. Figure 4(b) shows a schematic diagram of the light-receiving surface of the silicon-based liquid crystal 22. The silicon-based liquid crystal 22 includes a driving circuit 220 and a liquid crystal layer 222 stacked together. The driving circuit 220 is used to refresh the light spot coverage area to form a grating pattern. Specifically, it controls the liquid crystal layer 222 to form a grating pattern in the light spot coverage area. The light spot coverage area is the area where the silicon-based liquid crystal 22 receives a single-wavelength light signal O11. The grating pattern adjusts the output angle of the single-wavelength light signal O11 incident on the silicon-based liquid crystal 22 to a first angle, thereby enabling the single-wavelength light signal O11 output by the silicon-based liquid crystal 22 to be transmitted to the branch port f1 through the multiplexer / demultiplexer 21.

[0057] Specifically, such as Figure 4 As shown in (b), the light spot coverage area includes N rows of pixels, where N is a positive integer greater than or equal to 2. The silicon-based liquid crystal 22 also includes electrode layers 221 and 223 disposed on both sides of the liquid crystal layer 222. The driving circuit 220 sequentially applies voltage to the electrode layers 221 and 223 on both sides of each row of pixels, causing the liquid crystal molecules in the pixel row to deflect and form the phase of the pixel row. The phase distribution of the N rows of pixels constitutes a grating pattern, which means that the grating pattern includes the phase of each of the N rows of pixels.

[0058] For example, triggering service protection switching requires wavelength selection switch 5 to switch from branch port f1 to branch port f2. Currently, the commonly used first type of driving method for silicon-based liquid crystal 22 includes:

[0059] Step S101: Receive the switching command.

[0060] Specifically, the driving circuit 220 of the silicon-based liquid crystal 22 receives the switching command issued by the controller of the wavelength selection switch 5.

[0061] The switching command includes the single-wavelength optical signal O11, the target output port of wavelength selection switch 5, and the optical power attenuation, such as... Figure 3 As shown, the target output port can be, for example, branch port f2. The optical power attenuation is the difference between the reference optical power of the single-wavelength optical signal O11 output from branch port f2 and the steady-state optical power of the single-wavelength optical signal O11 output from branch port f2. Specifically, reference optical power - steady-state optical power = optical power attenuation. Branch port f2 is used to indicate the output angle of the single-wavelength optical signal O11. For example, the transmission of the single-wavelength optical signal O11 to branch port f2 requires an output angle of a second angle. The optical power attenuation is used to indicate the steady-state optical power of the single-wavelength optical signal O11. For example, if the reference optical power of the single-wavelength optical signal O11 output from branch port f2 is known, the steady-state optical power of the single-wavelength optical signal O11 can be calculated from the sum of the reference optical power and the optical power attenuation of the single-wavelength optical signal O11 output from branch port f2.

[0062] Transmitting a single-wavelength optical signal O11 to the branch port f2 requires forming a target grating pattern in the area covered by the light spot.

[0063] In the wavelength selection switch 5, each port corresponds to a grating period. The grating period corresponding to a port is used to adjust the output angle of the single-wavelength optical signal to transmit the single-wavelength optical signal to that port. The correspondence between the port and the grating period is pre-stored in the driving circuit 220 of the silicon-based liquid crystal 22. The target grating pattern can be directly determined based on the grating period corresponding to the target output port and the optical power attenuation; or, in other words, the target grating pattern can be determined based on the output angle of the single-wavelength optical signal O11 and the steady-state optical power of the single-wavelength optical signal O11.

[0064] Step S102: Refresh the area covered by the light spot to form the target grating pattern.

[0065] Specifically, the driving circuit 220 is used to refresh the area covered by the light spot to form a target grating pattern. Specifically, it controls the liquid crystal layer 222 to form a target grating pattern in the area covered by the light spot. The target grating pattern adjusts the output angle of the single-wavelength light signal O11 incident on the silicon liquid crystal 22 to a second angle, so that the single-wavelength light signal O11 output by the silicon liquid crystal 22 is transmitted to the branch port f2 through the multiplexer / demultiplexer 21. When the single-wavelength light signal O11 output by the silicon liquid crystal 22 is transmitted to the branch port f2, the optical power of the single-wavelength light signal O11 reaches the steady-state optical power of the single-wavelength light signal O11 output by the branch port f2.

[0066] In this process, the silicon-based liquid crystal 22 refreshes N rows of pixels sequentially to form a grating pattern, resulting in a delay in refreshing the N rows of pixels. In step S102, it is not necessary to wait for the current frame of the light spot coverage area to finish refreshing. For example, if the current frame refreshes to the Y-th row of pixels in the light spot coverage area, step S102 will start refreshing from the (Y+1)-th row of the light spot coverage area to form the target grating pattern in the light spot coverage area.

[0067] Reference Figure 5 As shown in (a) of the present application, the embodiment of the present application provides a curve of the phase change over time of the first row of pixels in the light spot coverage area corresponding to the driving method of the first silicon-based liquid crystal 22, as shown in the figure. Figure 5 As shown in (a), the driving circuit 220 applies a voltage U1 to the electrode layers 221 and 223 on both sides of the first row of pixels, causing the liquid crystal molecules in the first row of pixels to deflect, ultimately changing the phase of the first row of pixels to the phase φ1 of the first row of pixels in the target grating pattern. Where a single-wavelength light signal O11 needs to be transmitted to the branch port f1, the phase of the first row of pixels in the grating pattern is φ0. Figure 5As shown in (a), the first silicon-based liquid crystal 22 driving method requires a time of t1-t0 to adjust the phase of the first row of pixels from phase φ0 to phase φ1. The switching time is relatively long, which will make the switching time of service protection switching longer.

[0068] The second commonly used driving method for silicon-based liquid crystal 22 includes:

[0069] Step S201: Receive the switching command.

[0070] Similar to step S101, it will not be repeated here.

[0071] Step S202: Determine the overdrive grating pattern.

[0072] For example, triggering a service protection switch requires the wavelength selection switch 5 to switch from branch port f1 to branch port f2. Before triggering the service protection switch, the grating pattern corresponding to the single-wavelength optical signal transmitted to branch port f1 is the initial state grating pattern, and the target grating pattern is the final state grating pattern. In step S202, specifically, the overdrive phase of the Xth row of pixels is obtained by mapping the phase of the Xth row of pixels in the initial state grating pattern to the phase of the Xth row of pixels in the final state grating pattern. The overdrive grating pattern includes the overdrive phases of each of the N rows of pixels, X∈[1,N]. The mapping rule for the overdrive phase of the Xth row of pixels is: within one frame, the phase of the Xth row of pixels changes from the phase of the Xth row of pixels in the initial state grating pattern to the phase of the Xth row of pixels in the final state grating pattern.

[0073] Step S203: Refresh the area covered by the light spot to form an overdrive grating pattern.

[0074] The driving circuit 220 is used to refresh the area covered by the light spot to form an overdrive grating pattern. Specifically, it controls the liquid crystal layer 222 to form an overdrive grating pattern in the area covered by the light spot.

[0075] Step S204: Refresh the area covered by the light spot to form the target grating pattern.

[0076] Similar to step S102, it will not be described in detail here.

[0077] The second driving method for the silicon-based liquid crystal 22 is also known as the overdrive driving method. (See reference...) Figure 5 As shown in (b) of this application, the embodiment of the present application provides a curve of the phase change over time of the first row of pixels in the light spot coverage area corresponding to the driving method of the second silicon-based liquid crystal 22, as shown in the figure. Figure 5As shown in (b), during step S203, the driving circuit 220 applies an overdrive voltage Umax to the electrode layers 221 and 223 on both sides of the first row of pixels, causing the liquid crystal molecules in the first row of pixels to deflect rapidly. Subsequently, during step S204, the driving circuit 220 applies a voltage U1 to the electrode layers 221 and 223 on both sides of the first row of pixels, stabilizing the phase of the first row of pixels at phase φ1, as shown in (b). Figure 5 As shown in (b), it takes t2-t0 time to adjust the phase of the first row of pixels from φ0 to phase φ1, thus reducing the switching time.

[0078] However, the second driving method for the silicon-based liquid crystal 22 has limited performance improvement on the switching time of the wavelength selective switch 5. Furthermore, for the wavelength selective switch 5, the switching time is determined by the change in optical power of the single-wavelength optical signal O11 output from branch port f2 from 0 to 90% of the steady-state optical power of branch port f2. For the optical switching device 1, the switching time is determined by the change in optical power of the optical signal O1 output from port c from 0 to 90% of the steady-state optical power of port c, such as... Figure 2 As shown, there is an optical fiber and a wavelength selective switch 7 between the branch port f2 of the wavelength selective switch 5 and the port c of the optical switching equipment 1. The optical signal O1 is delayed when transmitted through the optical fiber and the wavelength selective switch 7. The single-wavelength optical signal O11 output at the branch port f2 is 90% of the steady-state optical power of the branch port f2. The optical power of the single-wavelength optical signal O11 received by the wavelength selective switch 7 is also 90% of the steady-state optical power of the branch port f2. Therefore, to change the optical power of the optical signal O1 output at the port c from 0 to 90% of the steady-state optical power of the port c, a longer switching time is required, which will also make the switching time of service protection switching longer.

[0079] To improve the switching time of optical switching device 1, a third driving method for silicon-based liquid crystal 22 is required. This driving method is also known as an overdrive driving method with overshoot control. Specifically, as follows... Figure 6 As shown, the third method for driving the silicon-based liquid crystal 22 includes:

[0080] Step S301: Receive the switching command.

[0081] Similar to step S101, it will not be repeated here.

[0082] Step S302: Determine the optical power overshoot. In the third driving method of the silicon-based liquid crystal 22, the optical power of the single-wavelength optical signal O11 output from the branch port f2 is required to include the overshoot optical power, so as to improve the switching time of service protection switching. The optical power overshoot is the difference between the overshoot optical power of the single-wavelength optical signal O11 output from the branch port f2 and the steady-state optical power of the single-wavelength optical signal O11 output from the branch port f2.

[0083] Reference Figure 7 As shown, Figure 7 Curve 1 and Curve 2 shown are both curves depicting the change in optical power of the single-wavelength optical signal O11 output from branch port f2 of wavelength selection switch 5 over time. The steady-state optical power of both curves is P1. Figure 7 As shown, curves 1 and 2 tend to stabilize after time t5. The optical power after time t5 is called the steady-state optical power. The overshoot power of curve 1 is P2, and the overshoot power of curve 2 is P3. P2 is greater than P3. The optical power overshoot of curve 1, P2-P1, is greater than the optical power overshoot of curve 2, P3-P1. Figure 7 As shown, the overshoot optical power of curves one and two represents their respective peak values. The time when the optical power of the single-wavelength optical signal O11 output from branch port f2 of curve one reaches 90% of its steady-state optical power is t3. The time when the optical power of the single-wavelength optical signal O11 output from branch port f2 of curve two reaches 90% of its steady-state optical power is t4, which is later than t3. Therefore, the optical power overshoot is related to the switching time. In step S302, a suitable optical power overshoot can be determined based on the switching time.

[0084] Step S303: Determine the overdrive grating pattern based on the optical power overshoot.

[0085] For example, triggering a service protection switch requires switching wavelength selection switch 5 from branch port f1 to branch port f2. Before triggering the service protection switch, the grating pattern corresponding to branch port f1 is the initial grating pattern transmitted to the single-wavelength optical signal. In step S303, the final grating pattern needs to be determined based on the grating period, optical power attenuation, and optical power overshoot corresponding to branch port f2. Specifically, for example, if the optical power attenuation is 3dB and the optical power overshoot is 1dB, the overshoot optical power attenuation is calculated to be 2dB based on the optical power attenuation and optical power overshoot. The overshoot final grating pattern is then determined based on the grating period and overshoot optical power attenuation corresponding to branch port f2. Then, the overdrive phase of the Xth row of pixels is obtained by mapping the phase of the Xth row of pixels in the initial grating pattern with the phase of the Xth row of pixels in the overshoot final grating pattern. The overdrive grating pattern includes the overdrive phases of each of the N rows of pixels, where X∈[1,N]. The mapping rule for the overdrive phase of the Xth row of pixels is as follows: within one frame, the phase of the Xth row of pixels changes from the phase of the Xth row of pixels in the initial state grating pattern to the phase of the Xth row of pixels in the overdrive final state grating pattern.

[0086] The overdrive grating pattern will cause the optical power of the single-wavelength optical signal O11 output from the branch port f2 to include the overdrive optical power.

[0087] Step S304: Refresh the area covered by the light spot to form an overdrive grating pattern.

[0088] Similar to step S203, it will not be described again here. In the case where an overdrive grating pattern is formed in the area covered by the light spot, the optical power of the single-wavelength optical signal O11 output by the branch port f2 will change to the overdrive optical power.

[0089] Step S305: Refresh the area covered by the light spot to form the target grating pattern.

[0090] Similar to step S102, it will not be described in detail here.

[0091] In the third driving method of silicon-based liquid crystal 22, the switching time is related to the optical power overshoot. When the switching time is required to be shorter, the optical power overshoot needs to be increased. However, increasing the optical power may lead to the risk of instantaneous excessive power during service protection switching, causing the received optical signal-to-noise ratio (OSNR) to deteriorate and affecting the transmission link.

[0092] Therefore, embodiments of this application provide a driving method for a silicon-based liquid crystal 22, which can reduce the risk of excessive instantaneous power while shortening the switching time.

[0093] Reference Figure 8 As shown, an embodiment of this application provides a driving method for a silicon-based liquid crystal 22, the driving method comprising:

[0094] Step S401: Divide the area covered by the light spot into M sub-regions.

[0095] For example, such as Figure 9 As shown in (a), the light spot coverage area is the area where the silicon-based liquid crystal 22 receives the single-wavelength light signal O11. The light spot coverage area includes N rows of pixels; M is a positive integer greater than or equal to 2, N is a positive integer greater than or equal to 2, each sub-region includes at least 1 row of pixels, and the number of pixel rows included in the M sub-regions is N.

[0096] Specifically, in Figure 9In the light-receiving surface of the silicon-based liquid crystal 22 shown in (a), the light spot coverage area includes 6 rows of pixels, dividing the light spot coverage area into two sub-regions: sub-region 1 and sub-region 2. Sub-region 1 includes 3 rows of pixels: the first, second, and third rows; sub-region 2 includes 3 rows of pixels: the fourth, fifth, and sixth rows. Sub-region 1 and sub-region 2 together include 6 rows of pixels. The light signal received by sub-region 1 is a partial single-wavelength light signal O11, and the light signal received by sub-region 2 is also a partial single-wavelength light signal O11.

[0097] like Figure 8 As shown, before step S401, there is also step S400: receiving a switching command. Similar to step S101 above, it will not be described again here.

[0098] Following step S401, step S402 is executed, sequentially refreshing M sub-regions to form a first grating pattern. At least two sub-regions have different overshoot power in their output optical signals based on the first grating pattern. In step S402, it is not necessary to wait for the current frame of the spot-covered area to finish refreshing. For example, if the current frame refreshes to the Y-th pixel row of the spot-covered area, step S402 starts refreshing from the (Y+1)-th row of the spot-covered area to form the first grating pattern in the spot-covered area, where Y∈[1,N-1]. When Y equals N, step S402 starts refreshing from the 1st row of the spot-covered area.

[0099] Then, step S403 is executed to sequentially refresh M sub-regions to form a second grating pattern. This second grating pattern, also called the target grating pattern, is specifically determined in step S400 based on the output angle and steady-state optical power of the single-wavelength optical signal O11. In step S402, it is not necessary to wait for the current frame to finish refreshing the area covered by the light spot. For example, if the current frame refreshes to the Y-th row of pixels in the area covered by the light spot, step S402 starts refreshing from the (Y+1)-th row of the area covered by the light spot to form the second grating pattern in the area covered by the light spot, where Y∈[1,N-1]. When Y equals N, step S402 starts refreshing from the first row of the area covered by the light spot.

[0100] After the second grating pattern is formed in the M sub-regions, the above-mentioned trigger service protection switching has been completed. The single-wavelength optical signal output by the silicon-based liquid crystal 22 is transmitted to the branch port f2 of the wavelength selection switch 5, and the optical power of the single-wavelength optical signal O11 output by the light spot coverage area will eventually reach the steady-state optical power of the single-wavelength optical signal O11.

[0101] exist Figure 8During the execution of the driving method of the silicon-based liquid crystal 22 shown, the difference between the overshoot power of the single-wavelength optical signal output from the light spot coverage area and the steady-state power of the single-wavelength optical signal is less than a preset value.

[0102] For example, in Figure 8 During the execution of the driving method for the silicon-based liquid crystal 22 shown, Figure 9 The optical power of the optical signal output from sub-region 1, as shown in (a), includes overshoot power, and the optical power of the optical signal output from sub-region 2 also includes overshoot power. The optical signal output from sub-region 1 is a partial single-wavelength optical signal O11, and the optical signal output from sub-region 2 is also a partial single-wavelength optical signal O11. Because the silicon-based liquid crystal 22 refreshes each pixel row sequentially, there is a delay in the refresh of different pixel rows, and the optical power of the optical signals output from sub-region 1 and sub-region 2 reaches the overshoot power at different times. Figure 9 In the silicon-based liquid crystal 22 shown in (a), sub-region 1 is refreshed first, followed by sub-region 2. The optical power change curve of the optical signal output by the first refreshed sub-region 1 is shown in Figure 2. Figure 9 As shown in curve (b) 3, sub-region 1 forms a partial pattern corresponding to sub-region 1 in the first grating pattern at t7. The optical power of the optical signal output by sub-region 1 based on the first grating pattern reaches the overshoot power P4 at time t7; the optical power change curve of the optical signal output by the subsequently refreshed sub-region 2 is shown in... Figure 9 As shown in curve (b) in Figure 4, sub-region 2 forms a partial pattern corresponding to sub-region 2 in the first grating pattern at t8. The optical power of the optical signal output by sub-region 2 based on the first grating pattern reaches the overshoot power P5 at time t8.

[0103] like Figure 9 As shown in (b), curve three stabilizes after time t9, and the optical power of curve four after time t9 is called the steady-state optical power P7 of the optical signal output by sub-region 1. Curve four stabilizes after time t9, and the optical power of curve four after time t9 is called the steady-state optical power P7 of the optical signal output by sub-region 2. Since the light spot coverage area is divided into sub-region 1 and sub-region 2, and sub-region 1 and sub-region 2 include the same number of pixel rows, and the percentage of the light spot coverage area occupied by sub-region 1 is the same as the percentage of the light spot coverage area occupied by sub-region 2, the steady-state optical power of the optical signal output by sub-region 1 is equal to the steady-state optical power of the optical signal output by sub-region 2.

[0104] The optical power variation curve of the optical signal output from sub-region 1 is superimposed with the optical power variation curve of the optical signal output from sub-region 2 to form Figure 9 The optical power variation curve of the single-wavelength optical signal O11 output from the area covered by the light spot shown in (c) is as follows: Figure 9As shown in (c), the optical power variation curve of the single-wavelength optical signal O11 output from the area covered by the light spot first increases to the overshoot power of the single-wavelength optical signal O11, then decreases, and finally flattens out. Figure 9 As shown in (c), the overshoot power of the single-wavelength optical signal O11 output from the area covered by the light spot is P6, and the optical power of the single-wavelength optical signal O11 after time t9 is called the steady-state optical power of the single-wavelength optical signal O11. The difference between the overshoot power and the steady-state optical power of the single-wavelength optical signal O11 output from the area covered by the light spot is relatively small. Additionally, as... Figure 9 (b) and Figure 9 As shown in (c), the time when the optical power of the single-wavelength optical signal O11 output by the silicon-based liquid crystal 22 reaches 90% of the steady-state optical power is t6.

[0105] Specifically, the overshoot power of the optical signal output by sub-region 1 based on the first grating pattern is different from that of the optical signal output by sub-region 2 based on the first grating pattern. This is to ensure that the difference between the overshoot power of the single-wavelength optical signal O11 output by the light spot coverage area and the steady-state optical power of the single-wavelength optical signal O11 is less than a preset value. The preset value can be determined according to the difference between the maximum optical power that the optical network where the silicon-based liquid crystal 22 is located can accept and the steady-state optical power of the single-wavelength optical signal O11.

[0106] exist Figure 8 In the driving method of the silicon-based liquid crystal 22 shown, a preset value is determined according to the difference between the maximum optical power that the optical network in which the silicon-based liquid crystal 22 is located and the steady-state optical power of the single-wavelength optical signal O11. By adjusting the first grating pattern, the overshoot optical power of the optical signal output by at least two sub-regions based on the first grating pattern is different. This makes the difference between the overshoot optical power of the single-wavelength optical signal O11 output by the light spot coverage area and the steady-state optical power of the single-wavelength optical signal O11 less than the preset value. In this way, the switching time of the silicon-based liquid crystal 22 can be shortened while taking into account the instantaneous maximum optical power of the single-wavelength optical signal output by the silicon-based liquid crystal 22, reducing the risk of the single-wavelength optical signal O11 output by the silicon-based liquid crystal 22 having excessively high instantaneous power.

[0107] For example, the above example divides the light spot coverage area into sub-region 1 and sub-region 2, and the number of pixel rows in sub-region 1 is equal to the number of pixel rows in sub-region 2. In some embodiments, the number of pixel rows in sub-region 1 is not equal to the number of pixel rows in sub-region 2. For example, sub-region 1 includes 2 pixel rows, namely the first pixel row and the second pixel row; sub-region 2 includes 4 pixel rows, namely the third pixel row, the fourth pixel row, the fifth pixel row, and the sixth pixel row. In other embodiments, the light spot coverage area can also be divided into multiple sub-regions, for example, M, where M is greater than 2. When the first grating pattern is formed by sequentially refreshing the M sub-regions, the overshoot power of the optical signal output by at least two of the M sub-regions is different, so that the difference between the overshoot power of the single-wavelength optical signal O11 output by the light spot coverage area and the steady-state power of the single-wavelength optical signal O11 is less than a preset value.

[0108] Reference Figure 10 As shown, in Figure 8 In the driving method of the silicon-based liquid crystal 22 shown, before step S402, the method further includes:

[0109] Step S4011: Determine the overshoot optical power of the output optical signal of the M sub-regions based on the M optical power overshoot corresponding to the M sub-regions.

[0110] Wherein, the optical power overshoot is the difference between the overshoot optical power of the optical signal output from the sub-region and the steady-state optical power of the optical signal output from the sub-region. Specifically, overshoot optical power - steady-state optical power = optical power overshoot, and the optical power overshoot can be a positive number, a negative number, or 0. Figure 9 In curve 3 shown in (b), the optical power overshoot of sub-region 1 is the overshoot optical power P4 - steady-state optical power P7, and the optical power overshoot of sub-region 1 is a positive number; the optical power overshoot of sub-region 2 is the overshoot optical power P5 - steady-state optical power P7, and the optical power overshoot of sub-region 2 is a negative number.

[0111] For example, the optical power overshoot corresponding to each of the M sub-regions can be preset in the driving circuit 220 of the silicon liquid crystal 22, or the value of M and the M optical power changes can be input to the driving circuit 220 of the silicon liquid crystal 22 in advance.

[0112] Step S4012: Determine the first grating pattern based on the overshoot power of the optical signals output from the M sub-regions.

[0113] For example, in step S4012, the overshoot final state grating pattern is determined based on the grating period corresponding to branch port f2, the optical power attenuation, and M optical power overshoots. Specifically, the M optical power overshoots are the optical power overshoot corresponding to sub-region 1, for example, 2dB, and the optical power overshoot corresponding to sub-region 2, for example, -2dB. Assuming, for example, the optical power attenuation is 3dB, the overshoot optical power attenuation of sub-region 1 is calculated to be 1dB based on the optical power attenuation and the optical power overshoot, and the overshoot optical power attenuation of sub-region 2 is calculated to be 5dB. The first overshoot final state grating pattern is determined based on the grating period corresponding to branch port f2 and the overshoot power attenuation of 1dB in sub-region 1; the second overshoot final state grating pattern is determined based on the grating period corresponding to branch port f2 and the overshoot power attenuation of 5dB in sub-region 2. The phase distribution of the first to third pixel rows in the first overshoot final state grating pattern is spliced ​​with the phase distribution of the fourth to sixth pixel rows in the second overshoot final state grating pattern to form the overshoot final state grating pattern. In step S4012, the grating pattern corresponding to the branch port f1 transmitted by the single-wavelength optical signal is the initial state grating pattern. Subsequently, the overdrive phase of the Xth pixel row is obtained by mapping the phase of the Xth pixel row in the initial state grating pattern with the phase of the Xth pixel row in the overshoot final state grating pattern. The overdrive grating pattern includes the overdrive phase of each of the N pixel rows, where X∈[1,6]. The mapping rule for the overdrive phase of the Xth row of pixels is as follows: within one frame, the phase of the Xth row of pixels changes from the phase of the Xth row of pixels in the initial state grating pattern to the phase of the Xth row of pixels in the overdrive final state grating pattern.

[0114] After obtaining the overdrive grating pattern, it is also necessary to obtain the pixel row pointer position of the current frame. The overdrive grating pattern is then cyclically shifted according to the pixel row pointer position to obtain a first grating pattern that matches the pixel row pointer position of the current frame. The matching principle is as follows: the phase of each pixel row (i.e., the starting pixel row) in the first grating pattern is incremented by 1 sequentially from the pixel row pointer position of the current frame (excluding the pixel row pointer position) for N rows of pixel rows in the overdrive grating pattern. If the counting process reaches the last row of the overdrive grating pattern, the next count returns to the first row. Therefore, the phase of the first pixel row (i.e., the starting pixel row) in the first grating pattern is the phase of the next pixel row in the overdrive grating pattern after the pixel row pointer position of the current frame.

[0115] For example in Figure 9In the area covered by the light spot shown in (a), the pixel row pointer position of the current frame is row 6, so the overdrive raster pattern is the first raster pattern. Given that M equals 2 and each sub-region includes 3 pixel rows, then sub-region 1 in step S101 corresponds to the 1st to 3rd pixel rows in the area covered by the light spot, and sub-region 2 corresponds to the 4th to 6th pixel rows in the area covered by the light spot.

[0116] For example, in Figure 9 In the area covered by the light spot shown in (a), the pixel row pointer position of the current frame is the 4th row. Given that M equals 2, and each sub-region includes 3 rows of pixels, sub-region 1 in step S101 corresponds to the 5th, 6th, and 1st rows of pixels in the spot coverage area, and sub-region 2 in the two sub-regions corresponds to the 2nd to 4th rows of pixels in the spot coverage area. The phase of the 1st row of pixels in the first grating pattern is the phase of the 5th row of pixels in the overdrive grating pattern, the phase of the 2nd row of pixels in the first grating pattern is the phase of the 6th row of pixels in the overdrive grating pattern, the phase of the 3rd row of pixels in the first grating pattern is the phase of the 1st row of pixels in the overdrive grating pattern, the phase of the 4th row of pixels in the first grating pattern is the phase of the 2nd row of pixels in the overdrive grating pattern, the phase of the 5th row of pixels in the first grating pattern is the phase of the 3rd row of pixels in the overdrive grating pattern, and the phase of the 6th row of pixels in the first grating pattern is the phase of the 4th row of pixels in the overdrive grating pattern. This means that, based on the pixel row pointer position of the current frame, we determine which pixel rows in the light spot coverage area correspond to each of the M sub-regions in the first raster pattern.

[0117] In some embodiments, taking into account the time difference between computation time and refresh time, the overdrive raster pattern can be cyclically shifted according to the pixel row pointer position and the time difference to obtain a first raster pattern that matches the pixel row pointer position of the current frame. For example, in Figure 9In the area covered by the light spot shown in (a), the pixel row pointer position of the current frame is the first row. The time difference will cause the pixel row position of the current frame to be refreshed by 2 more rows. Given that M equals 2, and each sub-region includes 3 rows of pixels, sub-region 1 in step S101 corresponds to the (1+2+1=4)th row, the 5th row, and the 6th row of pixels in the spot coverage area, and sub-region 2 in the two sub-regions corresponds to the 1st to 3rd rows of pixels in the spot coverage area. The phase of the 1st row of pixels in the first grating pattern is the phase of the 4th row of pixels in the overdrive grating pattern, the phase of the 2nd row of pixels in the first grating pattern is the phase of the 5th row of pixels in the overdrive grating pattern, the phase of the 3rd row of pixels in the first grating pattern is the phase of the 6th row of pixels in the overdrive grating pattern, the phase of the 4th row of pixels in the first grating pattern is the phase of the 1st row of pixels in the overdrive grating pattern, the phase of the 5th row of pixels in the first grating pattern is the phase of the 2nd row of pixels in the overdrive grating pattern, and the phase of the 6th row of pixels in the first grating pattern is the phase of the 3rd row of pixels in the overdrive grating pattern.

[0118] Then proceed with steps S402 and S403.

[0119] For example, in order to shorten the switching time of the silicon-based liquid crystal 22, the overshoot power of the optical signal output by at least one sub-region is greater than the steady-state power of the optical signal output by that sub-region. For example, the overshoot power of the optical signal output by the first sub-region out of M sub-regions may be greater than the steady-state power of the optical signal output by the first sub-region.

[0120] For example, in order to minimize the difference between the overshoot power and the steady-state power of the single-wavelength optical signal O11 output from the light spot coverage area, the overshoot power of the optical signal output from at least one sub-region is less than the steady-state power of the optical signal output from that sub-region. For example, the overshoot power of the optical signal output from the Mth sub-region out of M sub-regions may be less than the steady-state power of the optical signal output from that sub-region.

[0121] For example, in some embodiments, the overshoot power of the optical signals output from the M sub-regions gradually decreases. In other embodiments, the change in the overshoot power of the optical signals output from the M sub-regions follows a Gaussian distribution, with the overshoot power of the optical signals output from the M sub-regions first increasing and then decreasing.

[0122] For example, embodiments of this application also provide a silicon-based liquid crystal 22, such as... Figure 4 As shown, the silicon-based liquid crystal 22 includes a driving circuit 220 and a liquid crystal layer 222 stacked together. The driving circuit 220 is used to perform... Figure 8 or Figure 10The driving method of the silicon-based liquid crystal 22 shown controls the liquid crystal layer 222 to first form a first grating pattern and then form a second grating pattern in the area covered by the light spot.

[0123] For example, the above Figure 8 or Figure 10 The driving method for the silicon-based liquid crystal 22 shown can be implemented as a software functional module and sold or used as an independent product. This driving method for the silicon-based liquid crystal 22 can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application embodiment, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute... Figure 8 or Figure 10 The driving method of the silicon-based liquid crystal 22 shown includes all or part of the steps. Storage media for storing computer software products include various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0124] Optionally, embodiments of this application also provide a computer-readable storage medium storing a computer program or instructions, which, when executed on a computer, cause the computer to perform... Figure 8 or Figure 10 The driving method of the silicon-based liquid crystal 22 shown.

[0125] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software programs, it can be implemented entirely or partially in the form of a computer program product. This computer program product includes one or more computer instructions. When the computer program product is run on a computer, the computer executes the provisions of this application. Figure 8 or Figure 10 The driving method of the silicon-based liquid crystal 22 shown.

[0126] The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. Computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access, or it can contain one or more data storage devices such as servers or data centers that can be integrated with that medium. Available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives (SSDs)).

[0127] In some embodiments, such as Figure 3 As shown, in cases where it is necessary to transmit a portion of the single-wavelength optical signal O11 to branch port f1 and a portion to branch port f2, embodiments of this application also provide a driving method for a silicon-based liquid crystal 22, the driving method comprising:

[0128] Step S501: Divide the area covered by the light spot into M sub-regions.

[0129] Step S501 is similar to step S401, and will not be described in detail here.

[0130] For example, before step S501, the method further includes: step S500, receiving a beam splitting command.

[0131] Specifically, the driving circuit 220 of the silicon-based liquid crystal 22 receives the beam splitting command issued by the controller of the wavelength selection switch 5.

[0132] The splitting command includes a single-wavelength optical signal, transmitting the single-wavelength optical signal to M output ports, and the corresponding optical power attenuation for each of the M output ports. In this example, the single-wavelength optical signal is specifically the single-wavelength optical signal O11, M is 2, and the M ports are branch port f1 and branch port f2.

[0133] After step S501, step S502 is executed, and M grating patterns are output to the M sub-regions respectively.

[0134] Among them, the output angles of the optical signals output from the M sub-regions are different.

[0135] For example, such as Figure 11As shown, M equals 2. Based on the grating period and optical power attenuation corresponding to branch port f1, the target grating pattern corresponding to branch port f1 can be determined. The phase distribution of the first to third rows of pixels in the target grating pattern corresponding to branch port f1 forms the grating pattern of sub-region 1. The grating pattern of sub-region 1 is output to sub-region 1. The grating pattern of sub-region 1 adjusts the output angle of a portion of the single-wavelength optical signal O11 incident on sub-region 1 to the first angle, thereby enabling the portion of the single-wavelength optical signal O11 output from sub-region 1 to be transmitted to the branch end. f1; Based on the grating period and optical power attenuation corresponding to branch port f2, the target grating pattern corresponding to branch port f2 can be determined. The phase distribution of the 4th to 6th pixel rows in the target grating pattern corresponding to branch port f2 forms the grating pattern of sub-region 2. The grating pattern of sub-region 2 is output to sub-region 2. The grating pattern of sub-region 2 adjusts the output angle of part of the single-wavelength optical signal O12 incident on sub-region 2 to the second angle, thereby enabling part of the single-wavelength optical signal O11 output by sub-region 2 to be transmitted to branch port f2.

[0136] In some embodiments, for example, the wavelength selection switch 5 includes K branch ports and a monitoring port, where K is a positive integer greater than or equal to 2. In the driving method of the silicon-based liquid crystal 22 in the wavelength selection switch 5, M in steps S500, S501 and S502 is specifically 2. The angle of the partial single-wavelength light signal output by sub-region 1 is a first angle, so that the partial single-wavelength light signal output by sub-region 1 is transmitted to any branch port of the wavelength selection switch 5. The angle of the partial single-wavelength light signal output by sub-region 2 is a second angle, so that the partial single-wavelength light signal output by sub-region 2 is transmitted to the monitoring port of the wavelength selection switch 5, thereby realizing the beam splitting monitoring function of the wavelength selection switch.

[0137] In some embodiments, for example, the wavelength selective switch includes K branch ports, where K is a positive integer greater than or equal to 2, M in steps S500, S501 and S502 is equal to K, and the output angles of the partial single-wavelength optical signals output from the M sub-regions are all different, so that the partial single-wavelength optical signals output from the M sub-regions are respectively transmitted to the K branch ports of the wavelength selective switch 5 to realize the multi-port broadcast function of the wavelength selective switch.

[0138] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of this application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from the spirit and scope of this application. Thus, if such modifications and modifications of this application fall within the scope of the claims of this application and their equivalents, this application is also intended to include such modifications and modifications.

Claims

1. A method for driving a silicon-based liquid crystal, characterized in that, include: The light spot coverage area is divided into M sub-regions, the light spot coverage area is the area where the silicon-based liquid crystal receives single-wavelength light signals, and the light spot coverage area includes N rows of pixels; M and N are positive integers greater than or equal to 2. Each sub-region includes at least 1 row of pixels, and the sum of the number of pixel rows included in the M sub-regions is N. The M sub-regions are refreshed sequentially to form a first grating pattern, and at least two sub-regions have different overshoot power of the optical signal output based on the first grating pattern; The M sub-regions are refreshed sequentially to form a second grating pattern, which is determined by the output angle of the single-wavelength optical signal and the steady-state optical power of the single-wavelength optical signal. Wherein, the difference between the overshoot power of the single-wavelength optical signal output from the area covered by the light spot and the steady-state power of the single-wavelength optical signal is less than a preset value.

2. The driving method for silicon-based liquid crystal according to claim 1, characterized in that, Before sequentially refreshing the M sub-regions to form the first grating pattern, the process also includes: The overshoot power of the optical signal output by the M sub-regions is determined based on the M optical power overshoots corresponding to the M sub-regions. The optical power overshoot is the difference between the overshoot power of the optical signal output by the sub-region and the steady-state optical power of the optical signal output by the sub-region, and at least two optical power overshoots are different. The first grating pattern is determined based on the overshoot power of the optical signals output from the M sub-regions.

3. The driving method for silicon-based liquid crystal according to claim 1 or 2, characterized in that, The overshoot power of the optical signal output from at least one sub-region is greater than the steady-state power of the optical signal output from the sub-region.

4. The driving method for silicon-based liquid crystal according to any one of claims 1-3, characterized in that, The overshoot power of the optical signal output from at least one sub-region is less than the steady-state power of the optical signal output from the sub-region.

5. The driving method for silicon-based liquid crystal according to any one of claims 1-4, characterized in that, The overshoot power of the optical signals output from the M sub-regions gradually decreases; Alternatively, the overshoot power variation of the optical signals output from the M sub-regions conforms to a Gaussian distribution.

6. The driving method for silicon-based liquid crystal according to any one of claims 1-5, characterized in that, The driving method for silicon-based liquid crystals is applied to silicon-based liquid crystals in wavelength selective switches; Before dividing the light spot coverage area into M sub-regions, the method further includes: A switching command is received, the switching command including the single-wavelength optical signal, the target output port in the wavelength selection switch and the optical power attenuation amount, the target output port is used to indicate the output angle of the single-wavelength optical signal, and the optical power attenuation amount is used to indicate the steady-state optical power of the single-wavelength optical signal.

7. A silicon-based liquid crystal, characterized in that, The silicon-based liquid crystal includes a driving circuit and a liquid crystal layer stacked together. The driving circuit is used to execute the driving method of silicon-based liquid crystal according to any one of claims 1-6, so that a first grating pattern and a second grating pattern are formed in the light spot coverage area of ​​the liquid crystal layer.

8. A wavelength selective switch, characterized in that, The wavelength selection switch includes a multiplexer / demultiplexer and a silicon-based liquid crystal as described in claim 7; The multiplexer / demultiplexer is used to receive optical signals and output single-wavelength optical signals to the silicon-based liquid crystal. The silicon-based liquid crystal is used to output the single-wavelength optical signal to any port of the wavelength selection switch.

9. An optical switching device, characterized in that, It includes multiple wavelength selection switches as described in claim 8.

10. An optical network, characterized in that, The optical network includes a plurality of optical switching devices as described in claim 9, and the plurality of optical switching devices are connected by optical fibers.

11. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program or instructions, which, when executed on a computer, enable the computer to perform the driving method for a silicon-based liquid crystal as described in any one of claims 1-6.

12. A computer program product, characterized in that, When the computer program product is run on a computer, the computer executes the driving method of silicon-based liquid crystal as described in any one of claims 1-6.

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