A method, apparatus, medium and product for phase modulation of a liquid crystal on silicon device

Abstract

The application discloses a silicon-based liquid crystal device phase modulation method, equipment, medium and product, relates to the technical field of silicon-based liquid crystal spatial light modulation, and the method comprises the following steps: determining the grating period length of a target deflection angle; determining the number of pixels in a unit blazed period according to the grating period length and the pixel electrode size of the silicon-based liquid crystal device; constructing a mathematical simulation model corresponding to a periodic initial equal-phase difference stepped phase topography; superimposing a plurality of discrete harmonic components on the mathematical simulation model to obtain a stepped blazed grating topography superimposed with the discrete harmonic components; performing parameter matching optimization on the stepped blazed grating topography superimposed with the discrete harmonic components according to a set parameter range based on the diffraction order energy distribution to obtain an optimized stepped blazed grating topography; and using the optimized stepped blazed grating topography to modulate incident light of the silicon-based liquid crystal device. The application can effectively improve the main energy level diffraction efficiency of the silicon-based liquid crystal device and reduce other level stray light components.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of liquid crystal on silicon spatial light modulation, and in particular to a phase modulation method, device, medium and product of a liquid crystal on silicon device. BACKGROUND

[0002] In the field of optical communication, a reconfigurable optical add-drop multiplexer (ROADM) has gradually become a core component of a fiber communication network, and a wavelength-selective switch (WSS) is one of the key devices of a reconfigurable optical network, which can realize the routing function of the wavelength channel of the optical network, can output the input optical signal to any port without being affected by the wavelength, the direction of propagation and the position of the output port, has the characteristics of high flexibility and reconfigurability, in addition, the WSS can also have high-order functions such as energy balance, high port number, high integration, wide spectrum coverage, flexible grid and multicast, and has become a key technology to realize the ROADM. The implementation technologies of the WSS mainly include micro-electro-mechanical system mirror technology, liquid crystal technology, planar optical waveguide technology and liquid crystal on silicon (LCOS) technology. For a new generation of optical network, the WSS based on the LCOS technology is an extremely attractive solution, each pixel electrode in the LCOS can be independently controlled, can quantize the multi-stage phase modulation with high precision and flexibility, and does not need to be mechanically rotated, and has the advantages of high stability, high flexibility, flexible bandwidth, simple structure and the like. However, due to the discrete periodic distribution of the pixel electrodes in the LCOS, under the joint action of the single-slit diffraction of the pixel electrodes, the multi-beam interference between the stepped phases and the multi-beam interference between the phase topographies of the liquid crystal blazed grating, a multi-order stray light energy is formed in addition to the main energy level. These stray light energies reduce the diffraction efficiency of the LCOS device at the target port, increase the inter-port crosstalk in the WSS system, and reduce the port isolation, so it is necessary to eliminate the stray light distribution in addition to the main energy level, adjust the stray light to the main energy level, improve the diffraction efficiency of the LCOS device, and improve the isolation of the WSS. SUMMARY

[0003] The purpose of the present application is to provide a phase modulation method, device, medium and product of a liquid crystal on silicon device, which can effectively improve the main energy level diffraction efficiency of the liquid crystal on silicon device and reduce other order stray light components.

[0004] To achieve the above purpose, the present application provides the following solutions.

[0005] In a first aspect, the present application provides a phase modulation method of a liquid crystal on silicon device, comprising:

[0006] determine a grating period length of a target deflection angle; the target deflection angle is an angle between an incident port and a target port of a wavelength selective switch, and determine a blaze angle of a loaded blaze grating profile;

[0007] determine a pixel number in a unit blaze period according to the grating period length and a silicon-based liquid crystal device pixel electrode size; the silicon-based liquid crystal device pixel electrode size is determined based on a device intrinsic parameter or measured by a proportional scale tool;

[0008] construct a mathematical simulation model corresponding to a periodic initial equal phase difference stepwise phase profile; the mathematical simulation model is constructed based on a plurality of phase difference values; the phase difference values are determined according to the pixel number in the unit blaze period and a highest phase depth difference; the highest phase depth difference is a preset value;

[0009] superimpose a plurality of discrete harmonic components on the mathematical simulation model to obtain a stepwise blaze grating profile superimposed with the discrete harmonic components; the plurality of discrete harmonic components are different in frequency, amplitude and initial phase;

[0010] perform parameter matching optimization on the stepwise blaze grating profile superimposed with the discrete harmonic components according to a set parameter range based on diffraction order energy distribution, to obtain an optimized stepwise blaze grating profile; the parameters include harmonic amplitude and initial phase; the optimized stepwise blaze grating profile is used to modulate incident light of a silicon-based liquid crystal device.

[0011] Optionally, the grating period length is calculated according to a blaze grating grating equation; the blaze grating grating equation is:

[0012] d = (k * λ) / sin θ;

[0013] wherein d is the grating period length; k is a constant; λ is the wavelength of incident light; and θ is the target deflection angle.

[0014] Optionally, an expression of the mathematical simulation model is:

[0015]

[0016] φ ini is an expression of the mathematical simulation model; N is the pixel number in the unit blaze period; and n is the serial number of the pixel in the unit blaze period. is a phase difference value.

[0017] Optionally, an expression of the discrete harmonic component is:

[0018]

[0019] wherein φd is a discrete harmonic component; N is the number of pixels in a unit blazed period; n is the serial number of pixels in a unit blazed period; K is the number of harmonic orders; p i is the superimposed i-th order harmonic amplitude, ψ i is the superimposed i-th order harmonic initial phase; R is the superimposed harmonic function; d is the grating period length.

[0020] Optionally, the stepped blazed grating topography superimposed with discrete harmonic components specifically includes:

[0021]

[0022] In a second aspect, the present application provides a computer device, comprising: a memory, a processor to store a computer program on the memory and run the computer program on the processor, and the processor executes the computer program to implement the above-mentioned silicon-based liquid crystal device phase modulation method.

[0023] In a third aspect, the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the above-mentioned silicon-based liquid crystal device phase modulation method.

[0024] In a fourth aspect, the present application provides a computer program product, comprising a computer program, and the computer program is executed by a processor to implement the above-mentioned silicon-based liquid crystal device phase modulation method.

[0025] According to the embodiments provided by the present application, the following technical effects are disclosed:

[0026] The present application provides a silicon-based liquid crystal device phase modulation method, device, medium and product. By superimposing a limited number of discrete harmonic components on the periodic initial equal phase difference stepped phase topography, the discrete harmonic components and the zeroth order and high order position stray light are interfered, the amplitude, frequency, initial phase parameter optimization and matching of each harmonic component are combined synchronously to eliminate the stepped phase distribution diffraction non-main energy level order stray light energy, including zeroth order diffraction order and high order order stray light energy, and the harmonic component order is controlled to maintain the monotonicity of the phase depth topography distribution, greatly weaken the edge electric field effect caused by harmonic superposition, so that it can be applied to actual silicon-based liquid crystal spatial light modulator. The present application can effectively improve the main energy level diffraction efficiency of the silicon-based liquid crystal device, reduce other order stray light components, improve the isolation degree of the wavelength selection switch system, the method is simple and suitable for large-scale promotion. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings described below only constitute some of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0028] Figure 1 A flow chart of a silicon-based liquid crystal device phase modulation method in an embodiment of the present application;

[0029] Figure 2 A specific operation process schematic diagram of the silicon-based liquid crystal device phase modulation method provided in an embodiment of the present application in actual application;

[0030] Figure 3 An explanatory schematic diagram of the phase modulation method provided in an embodiment of the present application;

[0031] Figure 4 A diffraction efficiency distribution diagram of the silicon-based liquid crystal device phase modulation method provided in an embodiment of the present application under a 0.358° deflection angle;

[0032] Figure 5 A diffraction efficiency distribution diagram of the silicon-based liquid crystal device phase modulation method provided in an embodiment of the present application under a 0.611° deflection angle;

[0033] Figure 6 A diffraction efficiency distribution diagram of the silicon-based liquid crystal device phase modulation method provided in an embodiment of the present application under a 0.661° deflection angle;

[0034] Figure 7 A structural schematic diagram of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments only constitute some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0036] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0037] In an exemplary embodiment, as shown in Figure 1 A silicon-based liquid crystal device phase modulation method, the silicon-based liquid crystal device phase modulation method comprising:

[0038] Step 100: determining a grating period length of a target deflection angle. The target deflection angle is an angle between an incident port and a target port according to a wavelength selection switch, and the determined blaze angle of a loaded blaze grating profile.

[0039] Step 200: determining a pixel number in a unit blaze period according to the grating period length and a silicon-based liquid crystal device pixel electrode size. The silicon-based liquid crystal device pixel electrode size is determined based on intrinsic parameters of the device or measured by a proportional scale tool.

[0040] Step 300: constructing a mathematical simulation model corresponding to a periodic initial equal-phase difference stepped phase profile. The mathematical simulation model is constructed based on a plurality of phase difference values; the phase difference values are determined according to the pixel number in the unit blaze period and a highest phase depth difference; and the highest phase depth difference is a preset value.

[0041] Step 400: superimposing a plurality of discrete harmonic components on the mathematical simulation model to obtain a stepped blaze grating profile of the superimposed discrete harmonic components. The plurality of discrete harmonic components are different in frequency, amplitude and initial phase.

[0042] Step 500: performing parameter matching optimization on the stepped blaze grating profile of the superimposed discrete harmonic components according to a set parameter range based on diffraction order energy distribution to obtain an optimized stepped blaze grating profile. The parameters include harmonic amplitude and initial phase; and the optimized stepped blaze grating profile is used to modulate incident light of a silicon-based liquid crystal device.

[0043] Specifically, the grating period length is calculated according to a blaze grating equation; and the blaze grating equation is:

[0044] d = (k * λ) / sin θ;

[0045] wherein d is the grating period length; k is a constant; λ is an incident light wavelength; and θ is the target deflection angle.

[0046] In an embodiment, an expression of the mathematical simulation model is:

[0047]

[0048] φ ini is the expression of the mathematical simulation model; N is the pixel number in the unit blaze period; n is a serial number of the pixel in the unit blaze period; is the phase difference value.

[0049] An expression of the discrete harmonic component is:

[0050]

[0051] wherein φ dis a discrete harmonic component; N is the number of pixels in a unit blazed period; n is the serial number of pixels in a unit blazed period; K is the number of harmonic orders; p i is the superimposed i-th order harmonic amplitude, ψ i is the superimposed i-th order harmonic initial phase; R is a superimposed harmonic function; d is the grating period length.

[0052] The stepped blazed grating topography superimposed with discrete harmonic components specifically includes:

[0053]

[0054] The application also provides an application scenario of the silicon-based liquid crystal device phase modulation method. Specifically, the silicon-based liquid crystal device phase modulation method can be applied to how to effectively improve the LCOS device main energy level diffraction efficiency, reduce zero-order and high-order stray light energy, improve WSS port isolation, and realize high-quality communication of the WSS system. By superimposing discrete harmonic components with different frequencies, different amplitudes, and different initial phases on the initial equal-phase-difference stepped phase depth distribution topography, the zero-order and high-order diffraction stray light energy can be reduced.

[0055] Further, the relationship between the stepped phase depth distribution topography blazed period and the main energy level deflection angle θ and the incident light beam wavelength, i.e., the incident light wavelength λ, is as follows:

[0056] d = (k * λ) / sin θ

[0057] k is a constant, and the value of k is the quotient of the highest phase depth difference and 2π, k = 1, 2, 3,...

[0058] The grating period length d is the product of the pixel electrode size P and the number of pixels N in a unit period, N = d / P, and the highest phase depth difference of the stepped phase depth distribution topography can be 2kπ (k = 1, 2, 3,...), and the phase difference value between every two adjacent steps in a unit blazed period is the highest phase depth difference and the quotient of the number of pixels N in a unit blazed period,

[0059] The initial equal-phase-difference stepped phase depth topography, that is, the mathematical simulation model φ ini is:

[0060]

[0061] The sum expression of the superimposed K times harmonic components is:

[0062]

[0063] K is the highest harmonic number, that is, K represents the number of harmonic order, p is the superimposed harmonic amplitude, ψ is the superimposed harmonic initial phase, and R is the superimposed harmonic function.

[0064] The stepped phase depth distribution topography φ after superimposing multiple discrete harmonics is:

[0065]

[0066] Can be Periodic function.

[0067] The frequency, amplitude and initial phase of the multiple harmonics can be adjusted; the frequency of the multiple harmonics is respectively different integer multiples of the frequency of the stepped phase depth distribution topography; the harmonic can be a periodic function such as a sine wave, a cosine wave, a triangular wave, a square wave, etc.; the frequency, amplitude and initial phase of the multiple harmonics can be optimized to greatly reduce the zeroth and high-order diffraction stray light energy.

[0068] The multiple harmonics interfere together to realize the elimination of zeroth and high-order diffraction stray light; the stepped phase depth topography after superimposing multiple discrete harmonics has monotonicity, which is monotonically increasing or monotonically decreasing, and the monotonic change is beneficial to reduce the influence of the edge electric field effect, and the monotonicity is related to the blazed direction.

[0069] The present application superimposes discrete harmonic components with different frequencies, different amplitudes and different initial phases on the initial equal phase difference stepped phase depth distribution topography to reduce the zeroth and high-order diffraction stray light energy, realize high diffraction efficiency of the LCOS device diffraction main level and high port isolation of the WSS, effectively improve the high communication quality of the WSS system, and reduce energy consumption. The implementation method is simple, the optimization effect is significant, and it is suitable for large-scale promotion.

[0070] In actual application, as Figure 2 The specific operation process of the method can further include the following steps:

[0071] S101, the blazed angle of the blazed grating topography to be loaded by the silicon-based liquid crystal device is obtained according to the angle relationship between the incident port and the target port in the wavelength selective switch, and the grating period length d corresponding to the target deflection angle θ is calculated according to the grating equation of the blazed grating.

[0072] S102, the number of pixels in a unit blazed period is determined according to the blazed grating period length obtained in S101 and the pixel electrode size of the silicon-based liquid crystal device.

[0073] The pixel number per unit blazed period is calculated by the expression N=d / P, wherein N is the quotient of the blazed period length d and the pixel electrode size P; d is the grating period length in step S101; the pixel electrode size of the silicon-based liquid crystal device is the sum of the intrinsic electrode pixel size and the pixel gap, which can be determined by the intrinsic parameters of the device or measured under a microscope with a scale as a tool.

[0074] S103, after obtaining the pixel number per unit blazed period in step S102, constructing a periodic initial equal phase difference stepwise phase profile with 2kπ (k=1, 2, 3...) as the maximum phase depth; steps S101, S102, and S103 are steps for constructing a discrete initial equal phase difference stepwise phase profile.

[0075] The phase difference value between every two adjacent steps per unit blazed period is The maximum phase depth difference is The quotient of the maximum phase depth difference and the pixel number per unit blazed period N; wherein The value is 2kπ (k=1, 2, 3...); wherein N is the pixel number per unit period in step S102; the expression of the initial equal phase difference stepwise phase depth profile is

[0076] S104, superimposing discrete harmonic components with different frequencies, amplitudes, and initial phases on the periodic initial equal phase difference stepwise phase profile obtained in step S103, and eliminating non-principal energy level order stray light energy through multi-beam interference between the diffraction orders generated by the initial equal phase difference stepwise phase profile and the diffraction orders induced by the discrete harmonic components.

[0077] The expression of the sum of K harmonic components is The expression of superimposing discrete harmonic components on the initial equal phase difference stepwise phase profile is

[0078] S105, for the stepwise blazed grating profile constructed by superimposing discrete harmonic components in step S104, matching and optimizing, adjusting the frequency, amplitude, and initial phase of each discrete harmonic component, to eliminate stray light energy at zero order and high order.

[0079] For the principal energy level diffraction order k (the value of k is the same as that in step S101), the diffraction order M needs to be suppressed, and the discrete harmonic component that can effectively offset the M-order stray light energy is wherein p M is the harmonic amplitude, and ψ Mis the initial phase of the superimposed harmonic, R is the superimposed harmonic function; wherein, the harmonic amplitude p M The value of the initial phase ψ M is related to the diffraction order energy distribution generated by the initial equal phase difference step phase topography, the harmonic amplitude size represents the highest light energy amplitude that can be eliminated by the harmonic, and the initial phase determines the progress in the vibration period of the harmonic; for the requirement of eliminating the energy of multiple order stray light, multiple discrete harmonic components can be superimposed at the same time, and multiple orders of stray light can be suppressed at the same time; the values of the frequency, amplitude and initial phase of each discrete harmonic component are adjusted according to the energy distribution of each diffraction order obtained in the experiment as feedback information, and the zero order and high order stray light energy is reduced as the optimization target; the harmonic amplitude p M The value range of the initial phase ψ M is 0-2π.

[0080] S106, load the periodic step blazed grating topography superimposed with the discrete harmonic component obtained in step S105 on the silicon-based liquid crystal device, and irradiate the incident light on the silicon-based liquid crystal device. The blazed grating topography formed on the silicon-based liquid crystal device will modulate the incident light. The incident light beam will produce a phase difference under the modulation of the periodic blazed grating, and the light waves will interfere with each other to produce diffraction. The diffraction phenomenon follows the Helmholtz diffraction law and the Fraunhofer diffraction principle. The blazed grating makes the light beam deviate on the basis of the blazed grating equation, the main energy level position corresponds to the target port of the wavelength selection switch, and the stray light energy at the non-main energy level position is mutually eliminated under the interference between the diffraction caused by the superimposed harmonic component and the diffraction caused by the initial equal phase difference topography, so as to realize high isolation and high light efficiency of the wavelength selection switch.

[0081] The silicon-based liquid crystal device phase modulation method for realizing high-isolation and high-efficiency wavelength selection switch in the embodiment of the application superimposes a limited number of discrete harmonic components on the basis of the initial equal phase difference step phase topography, so that the discrete harmonic components and the zero order and high order position stray light produce interference, respectively, to eliminate the stray light energy of the non-main energy level order diffraction, including the zero order diffraction order and the high order stray light energy, improve the main energy level diffraction efficiency of the silicon-based liquid crystal device, reduce other order stray light components, and improve the isolation of the wavelength selection switch system.

[0082] The frequency, amplitude and initial phase of each discrete harmonic component are matched and optimized to eliminate the stray light energy at the zero order and high order, and the diffraction efficiency is defined as:

[0083] η i =D i / D o

[0084] In the formula, η is the diffraction efficiency of each order, and D i D represents the optical power at each order. o The light power reflected when no blazed grating is applied to a silicon-based liquid crystal device;

[0085] A stepped blazed grating morphology with discrete harmonic components superimposed is loaded onto a silicon-based liquid crystal device to modulate the incident light, achieving high isolation and high luminous efficiency of the wavelength selective switch. The formula for the wavelength selective switch isolation is:

[0086] I i =10log(η) i / max j≠i η j )

[0087] In the formula, I represents the isolation of the i-th target port of the wavelength selective switch, which is used to characterize the degree of crosstalk between stray light from non-target ports and the target port, and η i Let max be the diffraction efficiency of the i-th target port. j≠i η j This represents the highest diffraction efficiency among non-target ports.

[0088] Figure 3 This diagram illustrates a phase modulation method for silicon-based liquid crystal devices to achieve high isolation and high luminous efficiency wavelength selective switches. Within a single blaze period width, an initial equiphase-difference stepped phase depth distribution gradually increases with equal phase spacing differences. Based on this initial equiphase-difference stepped phase depth distribution, discrete first harmonics, second harmonics...K-1 harmonics, and K harmonics are superimposed (the harmonics in the diagram are shown as sinusoidal waveforms). The amplitude and phase of each harmonic are matched and set according to the order of energy to be eliminated.

[0089] Figure 4 The figure shows the diffraction efficiency distribution of a silicon-based liquid crystal device phase modulation method for achieving high isolation and high luminous efficiency wavelength selective switching at a deflection angle of 0.358°. Figure 4 The left-hand image shows the diffraction efficiency distribution of the initial equiphase-difference stepped phase depth distribution at a deflection angle of 0.358° (principal level position at 0.358°), within a global viewing angle range of -0.2° to +2.2° (diffraction efficiency values ​​range from 0% to 100%). The comparison of principal level diffraction efficiencies in the image shows that the principal level modulation energy generated by the phase depth distribution after superimposing a discrete sine wave is higher than that generated by the initial equiphase-difference stepped phase depth distribution. Figure 4The middle right side view is a partial enlarged view (the diffraction efficiency value is from 0% to 3% part), and it can be seen from the enlarged view that the stray light energy generated by the initial equal phase difference stepped phase depth profile on the zero order and each high order is higher than that generated by the phase depth distribution profile after superimposing the discrete sine wave, so superimposing the harmonic component of the discrete sine wave on the basis of the initial equal phase difference stepped phase depth profile is beneficial to improve the main order diffraction efficiency, and at the same time, reduce the stray light energy on the zero order and the high order. The main energy level energy is located at 0.358° deflection angle, the superimposed harmonic order and the corresponding amplitude and phase are respectively p1=0.01π, ψ1=0.01π, p2=0.01π, ψ2=0.07π, p3=0.2π, ψ3=0.1π, p4=0.01π, ψ4=0.001π, p5=0.01π, ψ5=0.1π, p6=0.1π, ψ6=0.01π, p7=0.01π, ψ7=0.01π, p8=0.01π, ψ8=0.01π, p9=

[0090] 0.01π, ψ9=0.01π.

[0091] Figure 5 The phase modulation method of the silicon-based liquid crystal device of the wavelength selection switch with high isolation and high light efficiency is shown in the diffraction efficiency distribution graph at 0.611° deflection angle. Figure 5 The middle left side view is the initial equal phase difference stepped phase depth distribution profile at 0.611° deflection angle (the main energy level position is located at 0.611°), and the diffraction efficiency distribution in the angle-0.2° to +2.2° range is shown in the global view (the diffraction efficiency value is from 0% to 100%), and it can be seen from the main energy level diffraction efficiency in the figure that the main energy level modulation energy generated by the phase depth distribution profile after superimposing the discrete sine wave is higher than that generated by the initial equal phase difference stepped phase depth profile, Figure 5 The middle right side view is a partial enlarged view (the diffraction efficiency value is from 0% to 3% part), and it can be seen from the enlarged view that the stray light energy generated by the initial equal phase difference stepped phase depth profile on the zero order and each high order is higher than that generated by the phase depth distribution profile after superimposing the discrete sine wave, so superimposing the harmonic component of the discrete sine wave on the basis of the initial equal phase difference stepped phase depth profile is beneficial to improve the main order diffraction efficiency, and at the same time, reduce the stray light energy on the zero order and the high order. The main energy level energy is located at 0.611° deflection angle, the superimposed harmonic order and the corresponding amplitude and phase are respectively p1=0.01π, ψ1=0.1π, p2=0.01π, ψ2=0.1π, p3=0.01π, ψ3=0.1π.

[0092] Figure 6The phase modulation method of the silicon-based liquid crystal device of the wavelength selective switch with high isolation and high light efficiency is a diffraction efficiency distribution diagram at a 0.661° deflection angle. Figure 6 The left side of the middle is an initial equal phase difference step phase depth distribution profile at a 0.661° deflection angle (the main energy level position is at 0.661°), and the diffraction efficiency distribution in the global viewing angle (the diffraction efficiency value is from 0% to 100%) in the range of-0.2° to +2.2°. As can be seen from the main energy level diffraction efficiency contrast in the diagram, the main energy level modulation energy generated by the phase depth distribution profile after superimposing the discrete sine wave is higher than that generated by the initial equal phase difference step phase depth profile, Figure 6 The right side of the middle is a local enlarged view (the diffraction efficiency value is from 0% to 3% part), and as can be seen from the enlarged view, the stray light energy generated by the initial equal phase difference step phase depth profile at the zero order and each high order is higher than that generated by the phase depth distribution profile after superimposing the discrete sine wave, so superimposing the discrete sine wave harmonic component on the basis of the initial equal phase difference step phase depth profile is conducive to improving the main order diffraction efficiency and reducing the stray light energy at the zero order and the high order. The superimposed harmonic order and the corresponding amplitude and phase are p1=0.05π, ψ1=0.1π, p2=0.01π, ψ2=0.1π, p3=0.01π, and ψ3=0.1π at the main energy level at the 0.661° deflection angle.

[0093] The application can effectively eliminate the stray light energy of the zero order and the high order except the main energy level by superimposing a limited number of discrete harmonic components on the basis of the initial step phase profile and simultaneously optimizing and matching the amplitude, frequency and initial phase parameters of each harmonic component, can effectively improve the main energy level diffraction efficiency of the silicon-based liquid crystal device, reduce other order stray light components, improve the isolation of the wavelength selective switch system, and is simple and suitable for large-scale promotion.

[0094] The application is dedicated to developing a phase modulation method of a silicon-based liquid crystal device of a wavelength selective switch with high isolation and high light efficiency, which can effectively eliminate the stray light energy of the zero order and the high order except the main energy level, effectively improve the diffraction efficiency of the LCOS device and the port isolation of the WSS, and realize high communication quality of the WSS system.

[0095] In an exemplary embodiment, a computer device, which can be a server or a terminal, is provided, and an internal structure diagram of the computer device can be as shown in Figure 7As shown in the figure. The computer device includes a processor, a memory, an input / output interface (I / O for short) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through the system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capability. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store phase modulation data. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals through network connection. The computer program is executed by the processor to implement a phase modulation method of a silicon-based liquid crystal device.

[0096] Those skilled in the art can understand that, Figure 7 The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. The specific computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement.

[0097] In an exemplary embodiment, a computer device is also provided, including a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps in the above method embodiments.

[0098] In an exemplary embodiment, a computer readable storage medium is provided, storing a computer program, which is executed by a processor to implement the steps in the above method embodiments.

[0099] In an exemplary embodiment, a computer program product is provided, including a computer program, which is executed by a processor to implement the steps in the above method embodiments.

[0100] It should be noted that the user information (including but not limited to user equipment information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or authorized by all parties, and the collection, use and processing of related data need to comply with relevant regulations.

[0101] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when the computer program is executed, the processes of the above-mentioned embodiments of the methods can be included. Any reference to memory, databases or other media used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0102] The database involved in the embodiments provided in the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a blockchain, etc., without being limited thereto. The processor involved in the embodiments provided in the present application can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., without being limited thereto.

[0103] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above embodiments are not described, but as long as the combinations of the technical features do not exist, they should be considered as the scope of the present application.

[0104] The principles and implementation modes of the present application are described by applying specific examples in this paper, and the above-mentioned embodiments are only used to help understand the method and its core idea of the present application. Meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed. In conclusion, the content of the present application should not be understood as a limitation.

Claims

1. A phase modulation method for a silicon-based liquid crystal device, characterized in that, The phase modulation method for the silicon-based liquid crystal device includes: The grating period length is used to determine the target deflection angle; the target deflection angle is the blaze angle of the loaded blazed grating morphology determined based on the angle between the incident port and the target port of the wavelength selection switch. The number of pixels per unit blaze period is determined based on the grating period length and the pixel electrode size of the silicon-based liquid crystal device; the pixel electrode size of the silicon-based liquid crystal device is determined based on the intrinsic parameters of the device or by measurement using a scale tool. A mathematical simulation model is constructed to correspond to a periodic initial equiphase step-type phase morphology. The mathematical simulation model is constructed based on multiple phase difference values. The phase difference values ​​are determined according to the number of pixels within a unit blaze period and the highest phase depth difference. The highest phase depth difference is a preset value. Multiple discrete harmonic components are superimposed on the mathematical simulation model to obtain a stepped blazed grating morphology with superimposed discrete harmonic components; the frequencies, amplitudes and initial phases of the multiple discrete harmonic components are different; Based on the diffraction order energy distribution, the morphology of the stepped blazed grating with superimposed discrete harmonic components is optimized by parameter matching according to a set parameter range to obtain the optimized stepped blazed grating morphology; the parameters include: harmonic amplitude and initial phase; the optimized stepped blazed grating morphology is used to modulate the incident light of the silicon-based liquid crystal device. The mathematical simulation model is expressed as follows: ； This is the expression for the mathematical simulation model; The number of pixels within a single flash period; The index of the pixel within a unit of flare period; This is the phase difference value; The expression for the discrete harmonic components is: ； in, For discrete harmonic components; This refers to the order of the harmonics; For the superimposed first Harmonic amplitude of order, For the superimposed first Initial phase of harmonics of order; These are superimposed harmonic functions; The grating period length is denoted by .

2. The phase modulation method for a silicon-based liquid crystal device according to claim 1, characterized in that, The grating period length is calculated based on the blazed grating equation; the blazed grating equation is: ； in, The grating period length; It is a constant; The wavelength of the incident light; The target deflection angle.

3. The phase modulation method for a silicon-based liquid crystal device according to claim 1, characterized in that, The stepped blazed grating morphology with superimposed discrete harmonic components specifically includes: 。 4. A computer device, comprising: A memory and a processor for storing a computer program on the memory and capable of running on the processor, characterized in that the processor executes the computer program to implement the phase modulation method for a silicon-based liquid crystal device according to any one of claims 1-3.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the phase modulation method for silicon-based liquid crystal devices as described in any one of claims 1-3.

6. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the phase modulation method for silicon-based liquid crystal devices as described in any one of claims 1-3.

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