Planar optical system simulation analysis method and equipment based on linked list processing

Abstract

The planar optical system simulation and analysis method based on linked list processing provided in the embodiment of the present invention records the coordinates of the contact points of light on the surface of the planar optical system in a linked list manner, simplifies the simulation of the planar optical system into processing of the linked list, and can quickly and accurately obtain the simulation results of the planar optical system. By adopting a multi-linked list approach, different areas on the surface of the planar optical system can be distinguished and independently optimized, and the optimization design of the entire area can be completed by connecting the linked lists. Compared with the non-sequential ray tracing algorithm, the present invention has the advantages of small calculation amount, fast simulation speed, and no need to consider energy thresholds. A computer device is also provided in the embodiment of the present invention.

Description

Technical Field

[0001] The invention relates to the field of optical simulation, and in particular to a planar optical system simulation analysis method based on linked list processing and a computer device. Background Art

[0002] When simulating a planar optical system with traditional optical software, it is generally necessary to use a non-sequential ray tracing algorithm. By using global coordinates, multiple ray tracings are performed on an optical surface. However, since the number of ray tracings is unknown, an energy threshold needs to be set. When the energy threshold is less than the energy threshold, the light at that location stops tracing. Therefore, in order to obtain accurate simulation results, the set threshold needs to be very low, which will bring a huge amount of calculations and reduce the speed of simulation. The method of the present invention records the coordinates of the contact points of light on the surface of the planar optical system in a linked list manner, and simplifies the simulation of the planar optical system into the processing of a linked list, which can quickly and accurately obtain the simulation results of the planar optical system. By adopting a multi-linked list approach, different areas on the surface of the planar optical system can be distinguished and independent optimization designs can be completed. The optimization design of the entire area can be completed by connecting the linked lists.

[0003] With the development of micro-nano processing technology, the application of planar optics is becoming more and more extensive. The design of planar optical elements such as diffractive optical elements, holographic optical elements, and metasurface elements has attracted more and more attention from researchers. When designing planar optical elements, optical simulation software needs to be used for modeling and optimization. Currently, the commonly used optical simulation software such as ZeMax, Lighttools, Tracepro, etc. are all built on the optical design of lens systems. Sequential ray tracing is the core algorithm of these optical software simulations. Sequential ray tracing needs to calculate the refraction and reflection of light on the surface of optical elements one by one, and each ray tracing uses the previous surface as the reference plane, which makes it very convenient to add or subtract optical elements. However, unlike the lens system, the light in the planar optical system only propagates between two surfaces, and the sequential ray tracing stops the operation after encountering the second surface. Typical planar optical systems are optical waveguide systems widely used in augmented reality glasses, helmets, head-up displays, etc.

[0004] Optical software from abroad has also proposed solutions for this type of planar optical system. Optical software such as ZeMax has developed non-sequential ray tracing based on sequential ray tracing. Compared with sequential ray tracing, non-sequential ray tracing uses global coordinates, and there is no distinction between front and back between optical surfaces. An optical surface can undergo multiple ray tracings, so it can be used to simulate planar optical systems such as optical waveguides. In terms of energy, this non-sequential ray tracing follows the method of sequential ray tracing, that is, the surface density of light is used to represent the intensity of light. Since the result of a ray tracing may be reflected, diffracted, etc., a ray will split into several sub-rays and propagate in different directions, so the total number of ray tracings becomes unknown. This requires setting an energy threshold. When the energy is less than the threshold, the ray tracing stops. In order to obtain accurate simulation results, a very low threshold needs to be set, that is, the initial light density needs to be set very high, which brings a huge amount of calculation and reduces the speed of simulation.

[0005] The non-sequential ray tracing method is used to calculate planar optical systems such as optical waveguides. It is necessary to set an energy threshold to determine the conditions for stopping ray tracing. Since the number of reflections and diffractions of light in a planar optical system such as an optical waveguide is related to the field of view of the light, if the energy threshold is set too low, the light of some field angles will not be able to accurately display the ray tracing of the entire system due to the stop calculation, affecting the simulation accuracy. If the energy threshold is set too high, it will bring a huge amount of unnecessary calculations and reduce the simulation speed. And if the planar optical system is optimized, taking the diffraction optical waveguide as an example, according to the non-sequential ray tracing method, only the diffraction grating area can be designed in blocks, that is, the bidirectional scattering distribution function or diffraction efficiency of each diffraction grating area is set as a parameter, and then the non-sequential ray tracing is used to traverse the entire system for each parameter optimization to obtain the optimized evaluation function value. This method is not only time-consuming, but also the final optimization effect is limited by the number of blocks, which requires multiple attempts and rich experience. Therefore, this non-sequential ray tracing method commonly used in optical software such as ZeMax is not suitable for calculating planar optical systems such as optical waveguides. Summary of the invention

[0006] In view of this, an embodiment of the present invention provides a planar optical system simulation analysis method and electronic device based on linked list processing, which has the advantages of small calculation amount, fast simulation speed, and no need to consider energy threshold.

[0007] In a first aspect, an embodiment of the present invention provides a planar optical system simulation analysis method based on linked list processing, comprising:

[0008] Recording the coordinates of the contact points of the light on the surface of the planar optical system in a linked list manner to obtain a linked list record, wherein the linked list record at least includes parameter input and coordinate record;

[0009] The linked list records are processed in a linked list to obtain optimization and analysis data of the planar optical system.

[0010] As an optional solution, the coordinates of the contact points of the light on the surface of the planar optical system are recorded in a linked list manner to obtain a linked list record, wherein the linked list record includes at least parameter input and coordinate record, including:

[0011] The steps for inputting the parameters are as follows:

[0012] The parameter input at least includes the input of the plane optical system parameters, the input of the light source parameters and the input of the incident information parameters, wherein the plane optical system parameters include basic geometric dimensions and material types, the light source parameters include at least the wavelength, diameter, polarization, and angle of the light beam, and the incident information parameters include at least the position coordinates of the incident point and the medium type of the incident space;

[0013] Steps for coordinate recording:

[0014] The propagation angle of the incident light after entering the diffractive optical waveguide is determined by the following grating equation for the coupled-in grating:

[0015]

[0016]

[0017] where k x and k y The projection length of the beam wave vector on the x-axis and y-axis, m x and m y are the diffraction orders in the x and y directions, and is the period of the coupling grating in the x and y directions.

[0018] As an optional solution, the method further includes:

[0019] For the grating-free area, the total reflection condition needs to be met.

[0020]

[0021] The coordinates of the total reflection point on the same surface (x i ,y i ) can be obtained by the following formula:

[0022]

[0023]

[0024] Among them, θ ow is the propagation angle of the light beam in the waveguide, t is the thickness of the waveguide, (x0, y0) are the coordinates of the starting contact point on the surface in the grating-free area, L(y) and R(y) are the left and right boundary contours of the grating-free area, respectively, and B(x) and T(x) are the upper and lower boundary contours of the grating-free area, respectively.

[0025] As an optional solution, the method further includes:

[0026] For the grating area, the diffraction order is used to determine the propagation angle after diffraction. The 0th order diffraction does not change the propagation direction, and the other diffraction orders will change the original propagation direction of the light beam. The propagation angle after diffraction can be obtained from the grating equation:

[0027]

[0028]

[0029] Among them, k front and k back are the wave vector components of the beam propagation before and after diffraction, respectively;

[0030] Use a linked list to record the coordinates of the diffraction points. C0 represents the position of the starting diffraction point on the surface where the grating is located. It is used to record the position coordinates of the starting diffraction point. For the 0th order diffraction, C i represents the diffraction point of the i-th 0th order diffraction, and is used to record the position coordinates of the diffraction point; for a certain diffraction point C i If other diffraction levels are needed, a branch chain is added to the chain table, using C i0 Equivalent representation C i , as the starting diffraction point position of the branch chain, and C ij represents the diffraction point of the subsequent j-th 0th order diffraction of the branch chain;

[0031] The coordinates of the 0th order diffraction point (x i ,y i ) is obtained by the following formula:

[0032]

[0033]

[0034] Where t is the thickness of the optical waveguide, (x0, y0) is the coordinate of the starting point of a chain in the grating area, is the propagation angle of the 0th order diffraction, L(y) and R(y) are the left and right boundary contour lines of the grating area, B(x) and T(x) are the upper and lower boundary contour lines of the grating area;

[0035] +1st order diffraction point coordinates (x i1 ,y i1 ) can be obtained by the following formula:

[0036]

[0037]

[0038] in, is the propagation angle of +1 diffraction. For the diffraction point with j>1, (x ij ,y ij ) is solved by using formulas 8 and 9 for the coordinates of the 0th order diffraction point.

[0039] As an optional solution, recording the contact point coordinates of the light on the surface of the planar optical system in a linked list manner to obtain a linked list record includes:

[0040] A linked list is recorded for each area of ​​the diffraction optical waveguide, and a linked list is established for the diffraction point coordinates of each grating area. There is a spatial association between the linked lists, and the header node of one linked list points to the node of another linked list.

[0041] As an optional solution, the optimization and analysis data at least include optimization of diffraction efficiency, output light intensity distribution and uniformity analysis.

[0042] As an optional solution, the method further includes:

[0043] Steps to optimize the diffraction efficiency of a diffractive waveguide

[0044] When designing a diffraction waveguide, the local micro-nano structure of the grating is changed so that the diffraction efficiency of each local diffraction order of the grating meets the requirements of energy distribution.

[0045] When the diffraction waveguide is in an L-shaped layout, for the outcoupling grating, the intensity of the light emitted from the outcoupling grating is made the same each time, and the conditions that need to be satisfied for the diffraction efficiency are obtained:

[0046] I i η i，+1 =I i η i，0 η i+1，+1 , (12)

[0047] Among them, η i，m represents the diffraction efficiency of the m-th order of the outcoupling grating at the i-th longitudinal pupil expansion position;

[0048] At the outcoupling grating, only the 0th and +1st diffraction orders are effective orders. Let the sum of the diffraction efficiencies of these two diffraction orders approach 1, so let,

[0049] η i，+1 +η i，0 =1, (13)

[0050] Substituting and simplifying, we get the recursive formula:

[0051]

[0052] The diffraction point of the last pupil expansion needs to have the highest diffraction efficiency of +1 order. The maximum diffraction efficiency is determined according to the grating type used, and the diffraction efficiency of +1 order of all the remaining diffraction points is obtained by reverse recursion.

[0053]

[0054] By recording the position coordinates of all diffraction points in the linked list so as to assign values ​​to each node of the linked list;

[0055] For the turning grating, let the light intensity leaving the turning grating after two adjacent pupil expansions be proportional to the pupil expansion number of the outcoupling grating, and we get:

[0056]

[0057] Among them, η i，m represents the diffraction efficiency of the mth order of the turning grating at the position of the i-th lateral pupil expansion, n i represents the number of diffractions inside the turning grating after the i-th lateral pupil expansion, N i represents the number of diffraction inside the out-coupling grating after the corresponding i-th lateral pupil expansion;

[0058] At the turning grating, only the 0th and -1st diffraction orders are effective. Let the sum of the diffraction efficiencies of the two diffraction orders approach 1, so let,

[0059] η i，-1 +η i，0 =1, (17)

[0060] Substituting and simplifying, we get the recursive formula:

[0061]

[0062] The above formula can be numerically solved to assign values ​​to the corresponding nodes in the linked list;

[0063] For incident light beams with different field angles, a set of linked lists recording the position coordinates of the diffraction points is obtained;

[0064] The diffraction efficiency values ​​of the repeated coordinate nodes in the linked list are weighted averaged, and then the coordinate information and diffraction efficiency values ​​contained in all the repeated coordinate nodes are plotted to obtain the overall optimal diffraction efficiency distribution map.

[0065] As an optional solution, the method further includes:

[0066] Steps of output light intensity distribution

[0067] For a light beam of a certain field angle, the ordered coordinates of all diffraction points of the light beam inside the diffraction waveguide are obtained by recording in a linked list, wherein each branch chain C corresponds to an exit point. The diffraction efficiency value of the node coordinate of the branch chain C is determined according to the optimized diffraction efficiency distribution diagram of each grating area, and then the light intensity value of the exit point is obtained by cumulative multiplication.

[0068]

[0069] All branches are traversed to obtain the outgoing light intensity distribution. The light intensity value is recorded in the node of the corresponding coordinate. For the outgoing light intensity distribution of the whole field of view, sampling is performed first and then the outgoing light intensity distribution step is executed.

[0070] As an optional solution, the method further includes:

[0071] Steps of uniformity analysis

[0072] Use linked list processing to determine spatial uniformity and angular uniformity, and define uniformity as the peak-to-valley ratio of light intensity.

[0073]

[0074] For spatial uniformity, the unit area S is set, and the light intensity of all coordinate points within the unit area is superimposed.

[0075]

[0076] Then the light intensity distribution of the entire field of view is traversed per unit area to obtain the spatial uniformity.

[0077]

[0078] For angular uniformity, set the unit area S and determine the uniformity U within the unit area. s , and then the light intensity distribution of the entire field of view is traversed per unit area and averaged to obtain the angle uniformity,

[0079]

[0080] Use linked list processing to obtain the light intensity distribution of the entire field of view and complete the uniformity analysis.

[0081] In a second aspect, an embodiment of the present invention further provides a computer device, including:

[0082] at least one processor; and

[0083] a memory communicatively connected to the at least one processor; wherein,

[0084] The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the above-mentioned planar optical system simulation analysis method based on linked list processing.

[0085] The planar optical system simulation and analysis method based on linked list processing provided in the embodiment of the present invention records the coordinates of the contact points of light on the surface of the planar optical system in a linked list manner, simplifies the simulation of the planar optical system into processing of a linked list, and can quickly and accurately obtain the simulation results of the planar optical system. By adopting a multi-linked list approach, different areas on the surface of the planar optical system can be distinguished and independently optimized, and the optimization design of the entire area can be completed by connecting the linked lists. Compared with the non-sequential ray tracing algorithm, the present invention has the advantages of small calculation amount, fast simulation speed, and no need to consider energy thresholds. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] Figure 1 A schematic flow chart of a planar optical system simulation analysis method based on linked list processing is provided in an embodiment of the present invention;

[0087] Figure 2 A schematic diagram of a process flow of link list recording in a planar optical system simulation analysis method based on link list processing is provided in an embodiment of the present invention;

[0088] Figure 3 A schematic structural diagram of a coupled grating linked list in a planar optical system simulation analysis method based on linked list processing is provided in an embodiment of the present invention;

[0089] Figure 4 A schematic diagram of optimizing a diffraction optical waveguide by a linked list method in a planar optical system simulation analysis method based on linked list processing is provided in an embodiment of the present invention;

[0090] Figure 5 A schematic diagram of output light intensity distribution of a linked list method in a planar optical system simulation analysis method based on linked list processing is provided in an embodiment of the present invention;

[0091] Figure 6 A schematic diagram of the structure of an L-shaped diffractive optical waveguide in a planar optical system simulation analysis method based on linked list processing is provided in an embodiment of the present invention;

[0092] Figure 7 A schematic diagram of diffraction points on the surface of an L-shaped diffraction optical waveguide in a planar optical system simulation analysis method based on linked list processing is provided in an embodiment of the present invention;

[0093] Figure 8 A schematic diagram of a transition grating linked list structure in a planar optical system simulation analysis method based on linked list processing is provided in an embodiment of the present invention;

[0094] Fig. 9 A schematic diagram of tracing the propagation path of the outgoing light in a planar optical system simulation analysis method based on linked list processing is provided in an embodiment of the present invention;

[0095] Fig.10 A structural block diagram of a computer device is provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0096] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0097] The terms "first", "second", "third", "fourth", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0098] Combination Figure 1 As shown, an embodiment of the present invention provides a planar optical system simulation analysis method based on linked list processing, comprising:

[0099] S101. Recording the coordinates of the contact points of light on the surface of a planar optical system in a linked list manner to obtain a linked list record, wherein the linked list record at least includes parameter input and coordinate record.

[0100] Taking the diffraction optical waveguide as an example, the explanation of linked list recording mainly includes two parts: parameter input and coordinate recording. Parameter input: parameter input mainly includes the input of plane optical system parameters, light source parameters and incident information parameters. The plane optical system parameters include the basic geometric dimensions and material type of the system; the light source parameters include the wavelength, diameter, polarization and angle of the light beam; the incident information parameters include the position coordinates of the incident point and the medium type of the incident space. Coordinate recording: For incident light at a certain angle, the propagation angle after entering the diffraction optical waveguide can be determined by the grating equation of the coupled grating.

[0101] S102, performing link list processing on the link list records to obtain optimization and analysis data of the planar optical system.

[0102] Linked list processing mainly completes the optimization and analysis of planar optical systems. The explanation of linked list processing will be taken as an example of diffraction optical waveguide, which mainly includes three parts: optimization of diffraction efficiency, distribution of output light intensity, and uniformity analysis. In the diffraction efficiency optimization step of the optical waveguide, when designing the diffraction optical waveguide, it is necessary to change the local micro-nano structure of the grating so that the diffraction efficiency of each local corresponding diffraction order of the grating meets the requirements of energy distribution. For gratings with different functions, the diffraction efficiency optimization method is different. The use of linked list processing can quickly and accurately obtain the optimal distribution of diffraction efficiency. In the output light intensity distribution step, the use of linked list processing can quickly obtain the output light intensity distribution. For a beam of a certain field angle, the coordinates of all diffraction points of the beam inside the diffraction optical waveguide have been obtained through linked list recording, and they are ordered, which means that each branch chain corresponds to an output point. By obtaining the optimized diffraction efficiency distribution diagram of each grating area, the diffraction efficiency value of the node coordinates of the branch chain can be found, and then the light intensity value of the output point can be obtained by cumulative multiplication. An important indicator for evaluating the display effect of diffraction waveguides in the uniformity analysis step is the uniformity of the output light field. Uniformity here has two meanings. The first is spatial uniformity, that is, the uniformity of the brightness of the entire image observed at different spatial positions within the eye movement range. The second is angular uniformity, that is, the uniformity of the brightness of different parts of an image, that is, the consistency of light intensity at different viewing angles. These two types of uniformity can be quickly obtained using linked list processing.

[0103] The planar optical system simulation and analysis method based on linked list processing provided in the embodiment of the present invention records the coordinates of the contact points of light on the surface of the planar optical system in a linked list manner, simplifies the simulation of the planar optical system into processing of a linked list, and can quickly and accurately obtain the simulation results of the planar optical system. By adopting a multi-linked list approach, different areas on the surface of the planar optical system can be distinguished and independently optimized, and the optimization design of the entire area can be completed by connecting the linked lists. Compared with the non-sequential ray tracing algorithm, the present invention has the advantages of small calculation amount, fast simulation speed, and no need to consider energy thresholds.

[0104] Combination Figures 2 to 8 As shown, an embodiment of the present invention further provides a planar optical system simulation and analysis method based on linked list processing, including linked list recording and linked list processing. The following takes a diffraction optical waveguide as an example to introduce an implementation scheme of an embodiment of the present invention.

[0105] The linked list record mainly completes the record of the position coordinates of the contact point of the light on the surface of the plane optical system. The linked list record will be explained by taking the diffraction light waveguide as an example, which mainly includes two parts: parameter input and coordinate recording.

[0106] (1) Parameter input:

[0107] Parameter input mainly includes the input of plane optical system parameters, light source parameters and incident information parameters. Among them, the plane optical system parameters include the basic geometric dimensions and material type of the system; the light source parameters include the wavelength, diameter, polarization and angle of the light beam; the incident information parameters include the position coordinates of the incident point and the medium type of the incident space.

[0108] (2) Coordinate record:

[0109] For incident light at a certain angle, the propagation angle after entering the diffraction waveguide can be determined by the grating equation of the coupled grating:

[0110]

[0111]

[0112] where k x and k y The projection length of the beam wave vector on the x-axis and y-axis, m x and m y are the diffraction orders in the x and y directions, and is the period of the coupling grating in the x and y directions.

[0113] It should be noted that after light enters the diffraction waveguide, it will encounter two situations during propagation: total reflection occurs in the area without grating, and diffraction occurs in the area with grating. Therefore, the diffraction waveguide can be divided according to the grating boundary.

[0114] For the grating-free area, the total reflection condition needs to be met.

[0115]

[0116] The coordinates of the total reflection point on the same surface (x i ,y i ) can be obtained by the following formula:

[0117]

[0118]

[0119] Where t is the thickness of the optical waveguide, and are the projections of the wave vector on the xz plane and the yz plane and the angle between them and the z axis, (x0, y0) are the coordinates of the initial contact point on a surface of the grating-free area, L(y) and R(y) are the left and right boundary contours of the grating-free area, B(x) and T(x) are the upper and lower boundary contours of the grating-free area.

[0120] For areas with gratings, it is necessary to consider the diffraction order used. The 0th order diffraction does not change the propagation direction, while other diffraction orders will change the original propagation direction of the beam. The propagation angle after diffraction can be obtained from the grating equation

[0121]

[0122]

[0123] Among them, k front and k back are the wave vector components of the light beam propagation before and after diffraction, respectively.

[0124] Use a linked list to record the coordinates of the diffraction points. C0 represents the position of the starting diffraction point on the surface where the grating is located, which is used to record the coordinates of the position. For the 0th order diffraction, C i represents the diffraction point of the i-th 0th order diffraction, and is used to record the position coordinates of the diffraction point. i If other diffraction orders are needed, such as +1 order diffraction, a branch chain is added to the chain table, using C i0 Equivalent representation C i , as the starting diffraction point position of the branch chain, and C ij represents the diffraction point of the subsequent j-th 0th order diffraction of the branch chain. iBy utilizing both +1 and -1 diffraction orders, two more branched chains C i0+ and C i0- Similarly, except for the 0th order diffraction, as many branches are added as the number of diffraction orders to be used. It should be noted here that the above symbols are only used to illustrate the rules for constructing the linked list.

[0125] The coordinates of the 0th order diffraction point (x i ,y i ) can be obtained by the following formula:

[0126]

[0127]

[0128] Where t is the thickness of the optical waveguide, (x0, y0) is the coordinate of the starting point of a chain in the grating area, is the propagation angle of the 0th order diffraction, L(y) and R(y) are the left and right boundary contour lines of the grating area, B(x) and T(x) are the upper and lower boundary contour lines of the grating area.

[0129] +1st order diffraction point coordinates (x i1 ,y i1 ) can be obtained by the following formula:

[0130]

[0131]

[0132] in, is the propagation angle of +1 diffraction. For the diffraction point with j>1, (x ij ,y ij ) can also be solved by the coordinate formula of the 0th order diffraction point.

[0133] -1st order diffraction point coordinates (x i1 ,y i1 ) can be obtained by the same method through formulas 8 to 11, which will not be repeated here.

[0134] Combination Figure 3As shown in the figure, there are multiple starting nodes, each starting node points to the node of the turning grating, and the subscript is used to indicate this pointing relationship. By recording each area of ​​the diffraction optical waveguide in a linked list, a linked list can be established for the diffraction point coordinates of each grating area. There is a spatial association between these linked lists, and this association needs to be expressed in a certain form. One method is to use the header node of a linked list to point to the node of another linked list. It should be noted that some areas have only one starting point, so the header is unique, and some areas have multiple parallel starting points, so there are multiple headers, and each header node needs to find the corresponding linked list node.

[0135] Combination Figure 4 and 5 As shown, in the embodiment of the present invention, the linked list processing mainly completes the optimization and analysis of the planar optical system. The linked list processing will be described by taking the diffraction optical waveguide as an example, which mainly includes three parts: optimization of diffraction efficiency, distribution of output light intensity, and uniformity analysis.

[0136] Optimizing the diffraction efficiency of diffractive waveguides

[0137] When designing a diffraction waveguide, it is necessary to change the local micro-nano structure of the grating so that the diffraction efficiency of each local grating corresponding to the diffraction order meets the requirements of energy distribution. For gratings with different functions, the methods of optimizing the diffraction efficiency are different. The use of linked list processing can quickly and accurately obtain the optimal distribution of diffraction efficiency.

[0138] Combination Figure 6 and 7 As shown, taking the L-shaped diffraction waveguide as an example, there are an incident grating 1, a turning grating 2, and an outcoupling grating 3. For the outcoupling grating, the intensity of the light emitted from the outcoupling grating is made the same each time, and the conditions that the diffraction efficiency needs to meet can be obtained:

[0139] I i η i，+1 =I i η i，0 η i+1，+1 ,#(12)

[0140] Among them, η i，m Represents the diffraction efficiency of the mth order of the outcoupling grating at the i-th longitudinal pupil expansion position.

[0141] At the outcoupling grating, only the 0th and +1st diffraction orders are effective. In order to increase the efficiency of energy use, the sum of the diffraction efficiencies of these two diffraction orders needs to approach 1. Therefore, let,

[0142] η i，+1 +η i，0 =1, (13)

[0143] Substituting and simplifying, we get the recursive formula:

[0144]

[0145] The diffraction point of the last pupil expansion needs to have the highest diffraction efficiency of +1 order. This maximum value can be determined according to the specific grating type used, so that the diffraction efficiency of +1 order of all remaining diffraction points can be obtained by reverse recursion.

[0146]

[0147] Since the position coordinates of all diffraction points have been recorded in the linked list, this recursive formula is equivalent to assigning values ​​to each node of the linked list. The above formula ensures that the light intensity coming out of the diffraction waveguide is the same after any column of longitudinal pupil expansion, so it is only necessary to ensure that the light intensity of all initial diffraction points after entering the outcoupling grating is the same.

[0148] Combination Figure 8 As shown, the linked list nodes correspond to Fig. 9 The diffraction point of the turning grating, for the turning grating, let the light intensity leaving the turning grating after two adjacent pupil expansions be proportional to the pupil expansion number of the out-coupling grating, we can get:

[0149] Among them, η i，m represents the diffraction efficiency of the mth order of the turning grating at the position of the i-th lateral pupil expansion, n i represents the number of diffractions inside the turning grating after the i-th lateral pupil expansion, N i represents the number of diffraction inside the out-coupling grating after the corresponding i-th lateral pupil expansion;

[0150] At the turning grating, only the 0th and -1st diffraction orders are effective. Let the sum of the diffraction efficiencies of the two diffraction orders approach 1, so let,

[0151] η i，-1 +η i，0 =1, (17)

[0152] Substituting and simplifying, we get the recursive formula:

[0153]

[0154] The above formula can be numerically solved to assign values ​​to the nodes corresponding to the linked list, such as Figure 8 shown.

[0155] Next, consider the case of full field of view. For incident light beams with different field of view angles, a set of linked lists recording the coordinates of the diffraction point positions can be obtained. After sampling the full field of view, there will be duplication in the coordinates of the diffraction point positions of light beams with different field of view angles. For the diffraction waveguide with an L-shaped layout as described above, the smaller the horizontal field of view angle of the light beam, the more times the lateral pupil expansion occurs, while the larger the vertical field of view angle of the light beam, the more times the longitudinal pupil expansion occurs. The more times the pupil expansion occurs, the more sensitive the final coupled light intensity is to the diffraction efficiency distribution. Therefore, for the case of repeated coordinates, the diffraction efficiency value corresponding to the field of view angle light beam with more times the pupil expansion should have a higher weight. It is only necessary to perform a weighted average on the diffraction efficiency values ​​of the repeated coordinate nodes, and then plot the coordinate information and diffraction efficiency values ​​contained in all these linked list nodes to obtain the overall optimal diffraction efficiency distribution map.

[0156] Outgoing light intensity distribution

[0157] The output light intensity distribution can be quickly obtained using linked list processing.

[0158] like Fig. 9 As shown in the figure, for a beam of a certain field angle, the coordinates of all diffraction points of the beam inside the diffraction waveguide have been obtained by recording in a linked list, and they are in order. This means that each branch chain C corresponds to an exit point. In (1), we have obtained the optimized diffraction efficiency distribution diagram of each grating area, from which we can find the diffraction efficiency value of the node coordinate of branch chain C, and then multiply it to get the light intensity value of the exit point.

[0159]

[0160] By traversing all branches, the outgoing light intensity distribution is obtained, and the light intensity value can be recorded in the node of the corresponding coordinate. For the outgoing light intensity distribution of the full field of view, it is only necessary to sample and then perform the above operations.

[0161] Uniformity analysis

[0162] An important indicator for evaluating the display effect of diffraction waveguides is the uniformity of the output light field. Uniformity here has two meanings. The first is spatial uniformity, that is, the uniformity of the brightness of the entire image observed at different spatial positions within the eye movement range. The second is angular uniformity, that is, the uniformity of the brightness of different parts of an image, that is, the consistency of light intensity at different viewing angles. These two types of uniformity can be quickly obtained using linked list processing.

[0163] We define uniformity as the peak-to-valley ratio of light intensity,

[0164]

[0165] For spatial uniformity, the unit area S is set, and the light intensity of all coordinate points within the unit area is superimposed.

[0166]

[0167] Then the full field of view light intensity distribution in (2) is traversed per unit area to obtain the spatial uniformity,

[0168]

[0169] For angular uniformity, set the unit area S and find the uniformity U within the unit area s , and then the full field of view light intensity distribution in (2) is traversed per unit area and averaged to obtain the angle uniformity,

[0170]

[0171] Therefore, after using linked list processing to obtain the light intensity distribution of the entire field of view, it is easy to perform uniformity analysis.

[0172] The planar optical system simulation analysis method based on linked list processing provided in the embodiment of the present invention has the following advantages:

[0173] 1. The linked list recording method is used to avoid the huge amount of calculation of ray tracing, and the propagation path of light in the plane optical system can be quickly obtained.

[0174] 2. The linked list processing method can accurately obtain the optimization results of the plane optical system and quickly obtain various indicators of the output light.

[0175] It should be noted that the linked list structure used in the present invention may also adopt a tree structure for a specific planar optical system, and a linked list with branches actually includes a tree structure.

[0176] Combination Fig.10 As shown, accordingly, an embodiment of the present invention further provides a computer device, including:

[0177] at least one processor; and

[0178] a memory communicatively connected to the at least one processor; wherein,

[0179] The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the above-mentioned planar optical system simulation analysis method based on linked list processing.

[0180] Accordingly, according to an embodiment of the present invention, the present invention also provides a computer device, a readable storage medium and a computer program product.

[0181] Fig.10 FIG. 1 is a schematic diagram of the structure of a computer device 12 provided in an embodiment of the present invention. Fig.10 A block diagram of an exemplary computer device 12 suitable for use in implementing embodiments of the present invention is shown. Fig.10 The computer device 12 shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present invention.

[0182] like Fig.10 As shown, computer device 12 is in the form of a general-purpose computing device. Computer device 12 is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic devices can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0183] Components of computer device 12 may include, but are not limited to, one or more processors or processing units 16 , a system memory 28 , and a bus 18 that connects various system components including system memory 28 and processing unit 16 .

[0184] Bus 18 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor or a local bus using any of a variety of bus architectures. By way of example, these architectures include, but are not limited to, an Industry Standard Architecture (ISA) bus, a Micro Channel Architecture (MAC) bus, an Enhanced ISA bus, a Video Electronics Standards Association (VESA) local bus, and a Peripheral Component Interconnect (PCI) bus.

[0185] The computer device 12 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by the computer device 12, including volatile and non-volatile media, removable and non-removable media.

[0186] The system memory 28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and / or cache memory 32. The computer device 12 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, the storage system 34 may be used to read and write non-removable, non-volatile magnetic media ( Fig.10not shown, usually called a "hard drive"). Although Fig.10 Not shown in the figure, a disk drive for reading and writing to a removable non-volatile disk (e.g., a "floppy disk"), and an optical disk drive for reading and writing to a removable non-volatile optical disk (e.g., a CD-ROM, a DVD-ROM, or other optical media) may be provided. In these cases, each drive may be connected to the bus 18 via one or more data medium interfaces. The memory 28 may include at least one program product having a set (e.g., at least one) of program modules that are configured to perform the functions of the embodiments of the present invention.

[0187] A program / utility 40 having a set (at least one) of program modules 42 may be stored, for example, in the memory 28, such program modules 42 including, but not limited to, an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment. The program modules 42 generally perform the functions and / or methods of the embodiments described herein.

[0188] The computer device 12 may also communicate with one or more external devices 14 (e.g., keyboards, pointing devices, displays 24, etc.), may communicate with one or more devices that enable a user to interact with the computer device 12, and / or may communicate with any device that enables the computer device 12 to communicate with one or more other computing devices (e.g., network cards, modems, etc.). Such communication may be performed via an input / output (I / O) interface 22. Furthermore, the computer device 12 may also communicate with one or more networks (e.g., local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) via a network adapter 20. As shown, the network adapter 20 communicates with other modules of the computer device 12 via a bus 18. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the computer device 12, including, but not limited to, microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0189] The processing unit 16 executes various functional applications and data processing by running the programs stored in the system memory 28, such as implementing the planar optical system simulation analysis method based on linked list processing provided in the embodiment of the present invention.

[0190] An embodiment of the present invention also provides a non-transitory computer-readable storage medium storing computer instructions, on which a computer program is stored, wherein when the program is executed by a processor, the planar optical system simulation and analysis method based on linked list processing provided in all the inventive embodiments of the present application is implemented.

[0191] The computer storage medium of the embodiment of the present invention may adopt any combination of one or more computer-readable media. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in combination with an instruction execution system, an apparatus, or a device.

[0192] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0193] The program code included in the computer-readable medium can be transmitted with any appropriate medium, including but not limited to wireless, electric wire, optical cable, RF, etc., or any suitable combination of the above. The computer program code for performing the operation of the present invention can be written in one or more programming languages ​​or their combinations, and the programming language includes object-oriented programming languages ​​such as Java, Smalltalk, C++, and also includes conventional procedural programming languages-such as "C" language or similar programming languages. The program code can be executed completely on the user's computer, partially on the user's computer, executed as an independent software package, partially on the user's computer and partially on the remote computer, or completely on the remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer by any type of network including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (for example, using an Internet service provider to connect to the Internet).

[0194] An embodiment of the present invention further provides a computer program product, including a computer program, which, when executed by a processor, implements the above-mentioned planar optical system simulation and analysis method based on linked list processing.

[0195] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in the present disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document is not limited here.

[0196] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A planar optical system simulation analysis method based on linked list processing, characterized in that: include: Recording the coordinates of the contact points of the light on the surface of the planar optical system in a linked list manner to obtain a linked list record, wherein the linked list record at least includes parameter input and coordinate record; Performing linked list processing on the linked list records to obtain optimization and analysis data of the planar optical system; The link list record is obtained by recording the coordinates of the contact points of the light on the surface of the planar optical system in a link list manner, wherein the link list record at least includes parameter input and coordinate record, including: Steps for entering the parameters: The parameter input at least includes the input of the plane optical system parameters, the input of the light source parameters and the input of the incident information parameters, wherein the plane optical system parameters include basic geometric dimensions and material types, the light source parameters include at least the wavelength, diameter, polarization, and angle of the light beam, and the incident information parameters include at least the position coordinates of the incident point and the medium type of the incident space; Steps for coordinate recording: The propagation angle of the incident light after entering the diffractive optical waveguide is determined by the following grating equation for the coupled-in grating: where k x and k y The projection length of the beam wave vector on the x-axis and y-axis, m x and m y are the diffraction orders in the x and y directions, and is the period of the coupling grating in the x and y directions; The step of recording the coordinates of the contact points of the light on the surface of the planar optical system in a linked list manner to obtain a linked list record comprises: A linked list is recorded for each area of ​​the diffraction optical waveguide, and a linked list is established for the diffraction point coordinates of each grating area. There is a spatial association between the linked lists, and the header node of one linked list points to the node of another linked list.

2. The planar optical system simulation analysis method based on linked list processing according to claim 1 is characterized in that: The method further comprises: For the grating-free area, the total reflection condition needs to be met. The coordinates of the total reflection point on the same surface (x i ,y i ) can be obtained by the following formula: Among them, θ ow is the propagation angle of the light beam in the waveguide, t is the thickness of the waveguide, (x0, y0) is the coordinate of the starting contact point on the surface in the grating-free area, L(y) and R(y) are the left and right boundary contours of the grating-free area, respectively, and B(x) and T(x) are the upper and lower boundary contours of the grating-free area, respectively.

3. The planar optical system simulation analysis method based on linked list processing according to claim 1, characterized in that: The method further comprises: For the grating area, the diffraction order is used to determine the propagation angle after diffraction, where the 0th order diffraction does not change the propagation direction, and other diffraction orders will change the original propagation direction of the light beam. The propagation angle after diffraction is obtained by the grating equation: Among them, k front and k back are the wave vector components of the beam propagation before and after diffraction, respectively; Use a linked list to record the coordinates of the diffraction points. C0 represents the position of the starting diffraction point on the surface where the grating is located. It is used to record the position coordinates of the starting diffraction point. For the 0th order diffraction, C i represents the diffraction point of the i-th 0th order diffraction, and is used to record the position coordinates of the diffraction point; for a certain diffraction point C i If other diffraction levels are needed, a branch chain is added to the chain table, using C i0 Equivalent representation C i , as the starting diffraction point position of the branch chain, and C ij represents the diffraction point of the subsequent j-th 0th order diffraction of the branch chain; The coordinates of the 0th order diffraction point (x i ,y i ) is obtained by the following formula: Where t is the thickness of the optical waveguide, (x0, t0) is the coordinate of the starting point of a chain in the grating area, is the propagation angle of the 0th order diffraction, L(y) and R(y) are the left and right boundary contour lines of the grating area, B(x) and T(x) are the upper and lower boundary contour lines of the grating area; +1st order diffraction point coordinates (x i1 ,y i1 ) can be obtained by the following formula: in, is the propagation angle of +1 order diffraction. For the diffraction point j>1, (x ij ,y ij ) is solved by using formulas 8 and 9 for the coordinates of the 0th order diffraction point.

4. The method for simulating and analyzing a planar optical system based on linked list processing according to any one of claims 2 to 3, characterized in that: The optimization and analysis data at least include optimization of diffraction efficiency, output light intensity distribution and uniformity analysis.

5. The planar optical system simulation analysis method based on linked list processing according to claim 4 is characterized in that: The method further comprises: Steps to optimize the diffraction efficiency of a diffractive waveguide When designing a diffraction waveguide, the local micro-nano structure of the grating is changed so that the diffraction efficiency of each local diffraction order of the grating meets the requirements of energy distribution. When the diffraction waveguide is in an L-shaped layout, for the outcoupling grating, the intensity of the light emitted from the outcoupling grating is made the same each time, and the conditions that need to be satisfied for the diffraction efficiency are obtained: I i or i,+1 =I i or i,0 or i+1,+1 , (12) Among them, η i，m represents the diffraction efficiency of the m-th order of the outcoupling grating at the i-th longitudinal pupil expansion position; At the outcoupling grating, only the 0th and +1st diffraction orders are effective orders. Let the sum of the diffraction efficiencies of these two diffraction orders approach 1, so let, or i,+1 +n i,0 =1, (13) Substituting and simplifying, we get the recursive formula: The diffraction point of the last pupil expansion needs to have the highest diffraction efficiency of +1 order. The maximum diffraction efficiency is determined according to the grating type used, and the diffraction efficiency of +1 order of all the remaining diffraction points is obtained by reverse recursion. By recording the position coordinates of all diffraction points in the linked list so as to assign values ​​to each node of the linked list; For the turning grating, let the light intensity leaving the turning grating after two adjacent pupil expansions be proportional to the pupil expansion number of the outcoupling grating, and we get: Among them, η i，m represents the diffraction efficiency of the mth order of the turning grating at the position of the i-th lateral pupil expansion, n i represents the number of diffractions inside the turning grating after the i-th lateral pupil expansion, N i represents the number of diffraction inside the out-coupling grating after the corresponding i-th lateral pupil expansion; At the turning grating, only the 0th and -1st diffraction orders are effective. Let the sum of the diffraction efficiencies of the two diffraction orders approach 1, so let, or i,-1 +n i,0 =1, (17) Substituting and simplifying, we get the recursive formula: The above formula can be numerically solved to assign values ​​to the corresponding nodes in the linked list; For incident light beams with different field angles, a set of linked lists recording the position coordinates of the diffraction points is obtained; The diffraction efficiency values ​​of the repeated coordinate nodes in the linked list are weighted averaged, and then the coordinate information and diffraction efficiency values ​​contained in all the repeated coordinate nodes are plotted to obtain the overall optimal diffraction efficiency distribution map.

6. The planar optical system simulation analysis method based on linked list processing according to claim 5 is characterized in that: The method further comprises: Steps of output light intensity distribution For a light beam of a certain field angle, the ordered coordinates of all diffraction points of the light beam inside the diffraction waveguide are obtained by recording in a linked list, wherein each branch chain C corresponds to an exit point. The diffraction efficiency value of the node coordinate of the branch chain C is determined according to the optimized diffraction efficiency distribution diagram of each grating area, and then the light intensity value of the exit point is obtained by cumulative multiplication. All branches are traversed to obtain the outgoing light intensity distribution. The light intensity value is recorded in the node of the corresponding coordinate. For the outgoing light intensity distribution of the whole field of view, sampling is performed first and then the outgoing light intensity distribution step is executed.

7. The planar optical system simulation analysis method based on linked list processing according to claim 4 is characterized in that: The method further comprises: Steps of uniformity analysis Use linked list processing to determine spatial uniformity and angular uniformity, and define uniformity as the peak-to-valley ratio of light intensity. For spatial uniformity, the unit area S is set, and the light intensity of all coordinate points within the unit area is superimposed. Then the light intensity distribution of the entire field of view is traversed per unit area to obtain the spatial uniformity. For angular uniformity, set the unit area S and determine the uniformity U within the unit area. s , and then the light intensity distribution of the entire field of view is traversed per unit area and averaged to obtain the angle uniformity, Use linked list processing to obtain the light intensity distribution of the entire field of view and complete the uniformity analysis.

8. A computer device, characterized in that: include: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the planar optical system simulation and analysis method based on linked list processing according to any one of claims 1 to 7.

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