Diffraction optical waveguide design method and diffraction optical waveguide

Abstract

The invention discloses a diffraction optical waveguide design method and a diffraction optical waveguide, and the method comprises the steps: selecting a target optimization parameter group, and obtaining a reference design value corresponding to each target optimization parameter in the target optimization parameter group, and a performance parameter expected value corresponding to the target optimization parameter group; obtaining a plurality of sample parameter groups; adding a random fluctuation quantity to at least one target optimization parameter in each pair of target optimization parameter groups to obtain a sample parameter group; the value range of the random fluctuation quantity corresponding to the target optimization parameter is determined according to the actual process error of the target optimization parameter; sample performance parameters corresponding to the sample parameter groups are determined, and modes of the sample performance parameters are screened out; and when the difference between the mode and the performance parameter expected value exceeds a threshold value, obtaining a sample parameter group corresponding to the mode, and adjusting the reference design value of the target optimization parameter group according to the sample parameter group. According to the invention, a direction can be provided for improving the production yield of the diffraction optical waveguide at a design end.

Description

Technical Field

[0001] The present application relates to the field of augmented reality, and in particular to a design method of a diffractive optical waveguide and a diffractive optical waveguide. Background Art

[0002] Optical waveguide display technology is one of the most challenging and complex problems in the field of augmented reality. Diffraction optical waveguide is a commonly used optical waveguide in optical waveguide display technology. Diffraction optical waveguides usually include at least coupling-in gratings and coupling-out gratings. Limited by the slight changes in microstructures such as coupling-in gratings and coupling-out gratings during the production process, the performance of the diffraction optical waveguides actually produced is often different from the designed performance, and the performance fluctuations under different architectures are not the same. The resulting large production fluctuations and low production yields are problems that have plagued the diffraction optical waveguide field for a long time. Therefore, the development of a design method for diffraction optical waveguides that can improve the production yield of diffraction optical waveguides and a method for analyzing production performance fluctuations have become technical priorities that technicians in the field need to solve urgently. Summary of the invention

[0003] In order to solve the above problems, the present application provides a design method of a diffractive optical waveguide capable of improving the production yield of the diffractive optical waveguide and a diffractive optical waveguide designed by the design method.

[0004] A design method for a diffractive optical waveguide, wherein the diffractive optical waveguide comprises at least an in-coupling grating and an out-coupling grating, wherein the design method for the diffractive optical waveguide comprises:

[0005] Selecting a target optimization parameter group from among various grating parameters in the coupling-in grating and the coupling-out grating, and obtaining reference design values ​​corresponding to various target optimization parameters in the target optimization parameter group, and expected values ​​of performance parameters corresponding to the target optimization parameter group;

[0006] Acquire a plurality of sample parameter groups; wherein, after adding a random fluctuation amount to at least one of the target optimization parameters in each target optimization parameter group, a sample parameter group is obtained; and the value range of the random fluctuation amount corresponding to the target optimization parameter is determined according to the actual process error of the target optimization parameter;

[0007] Determine sample performance parameters corresponding to each of the sample parameter groups, and screen out the mode of the sample performance parameters;

[0008] When the difference between the mode and the expected value of the performance parameter exceeds a threshold, a sample parameter group corresponding to the mode is obtained, and a reference design value of the target optimization parameter group is adjusted according to the sample parameter group.

[0009] In practice, the coupling-in grating is a slant-tooth grating, and the coupling-out grating is a straight-tooth grating; the target optimization parameter group includes: the height, duty cycle and slant-tooth angle of the coupling-in grating; and the height and duty cycle of the coupling-out grating.

[0010] In practice, the diffraction optical waveguide further includes a turning grating, and the turning grating is a straight tooth grating; the target optimization parameter group further includes: a height and a duty cycle of the turning grating.

[0011] In practice, the turning grating includes a plurality of turning sub-gratings, the height of the turning grating includes the height of each of the turning sub-gratings, and the duty cycle of the turning grating includes the duty cycle of each of the turning sub-gratings; and / or, the outcoupling grating includes a plurality of outcoupling sub-gratings, the height of the outcoupling grating includes the height of each of the outcoupling sub-gratings, and the duty cycle of the outcoupling grating includes the duty cycle of each of the outcoupling sub-gratings.

[0012] Practically, the actual process error of the target optimization parameter is related to the structure and material of the grating to which the target optimization parameter belongs and the production equipment used.

[0013] In practice, the expected value of the performance parameter includes an expected value of efficiency and an expected value of uniformity, and the sample performance parameter includes an efficiency sample and a uniformity sample; when the difference between the mode and the expected value of the performance parameter exceeds a threshold, obtaining a sample parameter group corresponding to the mode, and adjusting a reference design value of the target optimization parameter group according to the sample parameter group, comprises:

[0014] When the difference between the mode of the efficiency samples and the expected efficiency value exceeds a threshold, and the difference between the mode of the uniformity samples and the expected uniformity value exceeds a threshold, respectively obtaining a sample parameter group corresponding to the mode of the efficiency samples and a sample parameter group corresponding to the mode of the uniformity samples;

[0015] According to the proportion of the influence of the expected efficiency value and the expected uniformity value, based on the sample parameter groups corresponding to the mode of the efficiency samples and the mode of the uniformity samples, the reference design value of the target optimization parameter group is adjusted.

[0016] Preferably, the design method of the diffractive optical waveguide further includes:

[0017] After adding a random fluctuation amount to one of the target optimization parameters in the target optimization parameter group, a plurality of parameter evaluation groups are obtained, and according to the performance evaluation parameters corresponding to each of the plurality of parameter evaluation groups, a performance evaluation parameter fluctuation range corresponding to the target optimization parameter is obtained;

[0018] For the performance evaluation parameter fluctuation interval corresponding to each of the target optimization parameters, when the interval length is greater than the preset fluctuation interval, the corresponding target optimization parameter is determined to be a production feedback control parameter.

[0019] In practice, the adjusting the reference design value of the target optimization parameter group according to the sample parameter group further includes:

[0020] The reference design values ​​of the production feedback control parameters are preferentially adjusted according to the sample parameter group.

[0021] In practice, the coupling-in grating is a blazed grating; and the determining of the sample performance parameters corresponding to the respective sample parameter groups and screening out the mode of the sample performance parameters comprises:

[0022] Filtering out sample performance parameters corresponding to changes in grating tooth profile from the sample parameter group;

[0023] The sample performance parameters corresponding to each of the filtered sample parameter groups are determined, and the mode of the sample performance parameters is screened out.

[0024] A diffraction optical waveguide, comprising at least an in-coupling grating and an out-coupling grating, characterized in that each grating parameter in the in-coupling grating and the out-coupling grating corresponding to a target optimization parameter group is designed according to the design method of the diffraction optical waveguide described in any one of the above items.

[0025] The present application provides a design method for a diffraction optical waveguide and a diffraction optical waveguide designed by the design method. The random variation based on the actual process error is added to the reference design value of each target optimization parameter in the target optimization parameter group of the diffraction optical waveguide to simulate the randomness in the actual process error, thereby simulating the fluctuation of the performance of the diffraction optical waveguide under the actual process fluctuation of the target optimization parameter; when the expected value of the performance parameter deviates greatly from the sample performance parameter with an obvious concentration trend in the simulation, a part of the performance is discarded to bring the reference design value closer to the sample parameter value with a smaller actual process fluctuation. At this time, although the performance will be reduced, the performance distribution will account for a larger proportion and the volatility will be smaller, which can greatly improve the production yield. Thus, it can provide a direction for improving the production yield of the diffraction optical waveguide at the design end, and at the same time, it can evaluate the production stability under the design parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 A schematic diagram of the system architecture of a diffractive optical waveguide provided in an embodiment of the present application;

[0028] Figure 2 A schematic diagram of the distribution of efficiency samples corresponding to a plurality of sample parameter groups before the reference design value is adjusted in a design method of a diffractive optical waveguide provided in an embodiment of the present application;

[0029] Figure 3 A schematic diagram of the distribution of uniformity samples corresponding to a plurality of sample parameter groups before adjustment of reference design values ​​in a design method for a diffractive optical waveguide provided in an embodiment of the present application;

[0030] Figure 4 A schematic diagram of the distribution of efficiency samples corresponding to a plurality of sample parameter groups after the reference design value is adjusted in a design method for a diffractive optical waveguide provided in an embodiment of the present application;

[0031] Figure 5 A schematic diagram of the distribution of uniformity samples corresponding to a plurality of sample parameter groups respectively after the reference design value is adjusted in a design method of a diffractive optical waveguide provided in an embodiment of the present application;

[0032] Figure 6 A schematic diagram of fluctuation ranges of performance evaluation parameters corresponding to various target optimization parameters in a design method for a diffractive optical waveguide provided in an embodiment of the present application;

[0033] Figure ID:

[0034] 100: diffraction optical waveguide; 110: coupling-in grating; 120: turning grating; 130: coupling-out grating. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0036] The technical solution of the present application is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0037] On one hand, the present application provides a design method of a diffractive optical waveguide, wherein the diffractive optical waveguide at least includes an in-coupling grating and an out-coupling grating, and the design method of the diffractive optical waveguide includes:

[0038] S10, selecting a target optimization parameter group from among various grating parameters in the coupling-in grating and the coupling-out grating, and obtaining reference design values ​​corresponding to each target optimization parameter in the target optimization parameter group, and expected values ​​of performance parameters corresponding to the target optimization parameter group.

[0039] Practically, the coupling-in grating is a slant-tooth grating, and the coupling-out grating is a straight-tooth grating; the target optimization parameter group includes: the height, duty cycle and slant-tooth angle of the coupling-in grating, and the height and duty cycle of the coupling-out grating.

[0040] In practice, the diffraction optical waveguide further includes a turning grating. The turning grating may be a straight tooth grating. The target optimization parameter group further includes: a height and a duty cycle of the turning grating.

[0041] It is understood that the description of the grating tooth shape in the embodiment of the present application is only for illustration and does not limit the tooth shape of the grating structure in the technical solution of the present application. For example, the coupling-in grating is not limited to the slanted tooth grating, but can also be a straight tooth grating, a blazed grating, a step grating, etc. The turning grating and the coupling-out grating are also not limited to the straight tooth grating, but can also be a slanted tooth grating, a trapezoidal grating, etc.

[0042] Moreover, the target optimization parameter group may also include other grating parameters. In addition, the coupling-in grating, the turning grating and the coupling-out grating may all be one-dimensional gratings or two-dimensional gratings.

[0043] Pragmatically, the expected values ​​of performance parameters include but are not limited to expected values ​​of efficiency and expected values ​​of uniformity.

[0044] Exemplarily, the target optimization parameter group includes: the height, duty cycle and bevel angle of the coupling-in grating, the height and duty cycle of the turning grating, and the height and duty cycle of the coupling-out grating; the expected values ​​of the performance parameters include the expected value of efficiency and the expected value of uniformity. Among them, the reference design value of the height of the coupling-in grating is 300nm, the reference design value of the duty cycle of the coupling-in grating is 0.5, the reference design value of the bevel angle of the coupling-in grating is 30°, the reference design value of the height of the turning grating is 40nm, the reference design value of the duty cycle of the turning grating is 0.55, the reference design value of the height of the coupling-out grating is 45nm, the reference design value of the duty cycle of the coupling-out grating is 0.65, the expected value of efficiency is 175, and the expected value of uniformity is 0.33.

[0045] S20, obtaining several sample parameter groups; wherein, after adding a random fluctuation amount to at least one target optimization parameter in each pair of target optimization parameter groups, a sample parameter group is obtained; the value range of the random fluctuation amount corresponding to the target optimization parameter is determined according to the actual process error of the target optimization parameter.

[0046] Specifically, in this application, random fluctuations are added to the target optimization parameters of the target optimization parameter group to simulate the randomness of the actual process errors of the microstructure in the actual production process. A sample parameter group includes sample parameter values ​​corresponding to each target optimization parameter, and at least one sample parameter value of a target optimization parameter in each sample parameter group is a sample parameter value with random fluctuations added to its reference design value. In this way, a large number of sample parameter groups are obtained, and the sample performance parameters simulated by these sample parameter groups can objectively reflect the law of the influence of fluctuations of different target optimization parameters on fluctuations of sample performance parameters, which cannot be obtained in a short time through microscopic characterization. Among them, the number of sample parameter groups can be 300, 400, 500, or even more.

[0047] In practice, the actual process error of the target optimization parameter is related to the structure of the grating to which the target optimization parameter belongs, that is, to the grating tooth shape. Of course, the actual process error of the target optimization parameter is also related to other factors, such as the accuracy of the production equipment, the material of the grating structure to which the target optimization parameter belongs, etc. Among these influencing factors, the grating tooth shape has the greatest impact on the actual process error, followed by the accuracy of the production equipment, and the material of the grating structure has the least impact.

[0048] Exemplarily, the range of values ​​of the random fluctuation corresponding to the height of the coupled-in grating is (-15, 15), the range of values ​​of the random fluctuation corresponding to the duty cycle of the coupled-in grating is (-0.1, +0.1), and the range of values ​​of the random fluctuation corresponding to the bevel angle of the coupled-in grating is (-3°, 3°). For example, the reference design value of the height of the coupled-in grating is 300nm, and a random fluctuation of 5nm is added to the height of the coupled-in grating. Then, the sample parameter value of the height of the coupled-in grating is 305nm. For another example, the reference design value of the bevel angle of the coupled-in grating is 30°, and a random fluctuation of 1° is added to the bevel angle of the coupled-in grating. Then, the sample parameter value of the bevel angle of the coupled-in grating is 31°. For example, a set of design reference values ​​is {300, 0.5, 30°, 40, 0.55, 45, 0.65}, one sample parameter group is {305, 0.5, 30°, 40, 0.55, 45, 0.65}, and another sample parameter group is {305, 0.5, 31°, 40, 0.55, 45, 0.65}.

[0049] S30, determining sample performance parameters corresponding to respective sample parameter groups, and screening out the mode of the sample performance parameters.

[0050] Specifically, after obtaining several sample parameter groups, the sample performance parameters of the diffractive optical waveguide defined by each sample parameter group are simulated to obtain the sample performance parameters corresponding to each sample parameter group. Then, sample performance parameters with obvious concentration trends are screened out from these sample performance parameters, that is, the mode of the sample performance parameters. The mode of the sample performance parameters can predict the fluctuation stability in the production process to a certain extent.

[0051] S40, when the difference between the mode and the expected value of the performance parameter exceeds a threshold, a sample parameter group corresponding to the mode is obtained, and a reference design value of the target optimization parameter group is adjusted according to the sample parameter group.

[0052] In practice, the expected value of the performance parameter includes an expected value of efficiency and an expected value of uniformity, and correspondingly, the sample performance parameter includes an efficiency sample and a uniformity sample.

[0053] Pragmatically, S40 includes:

[0054] S41, when the difference between the mode of the efficiency samples and the expected value of the efficiency exceeds a threshold, and the difference between the mode of the uniformity samples and the expected value of the uniformity exceeds a threshold, respectively obtaining a sample parameter group corresponding to the mode of the efficiency samples and a sample parameter group corresponding to the mode of the uniformity samples;

[0055] S42, according to the influence ratio of the expected efficiency value and the expected uniformity value, based on the sample parameter groups corresponding to the mode of the efficiency samples and the mode of the uniformity samples, respectively, adjusting the reference design value of the target optimization parameter group.

[0056] Specifically, it can be understood that the performance requirements for products in different application scenarios will be different. When there are multiple performance parameters and the sample parameter groups corresponding to the modes of each performance parameter are different, the emphasis when adjusting the reference design value of the target optimization parameter group according to the multiple sample parameter groups is different according to the different importance of the performance parameters. For example, efficiency samples and uniformity samples are obtained for the two performance parameters of efficiency and uniformity at the same time. When the sample parameter groups corresponding to the modes of the efficiency samples and the modes of the uniformity samples are different, in application scenarios with higher uniformity requirements, the adjustment of the reference design value of the target optimization parameter group focuses on the sample parameter group corresponding to the mode of the uniformity samples; in application scenarios with higher efficiency requirements, the adjustment of the reference design value of the target optimization parameter group focuses on the sample parameter group corresponding to the mode of the efficiency samples.

[0057] The design method of a diffractive optical waveguide provided in the present application and the diffractive optical waveguide designed by the design method simulate the randomness in the actual process error by adding a random variation based on the actual process error to the reference design value of each target optimization parameter in the target optimization parameter group of the diffractive optical waveguide, thereby simulating the fluctuation of the performance of the diffractive optical waveguide under the actual process fluctuation of the target optimization parameter; when the expected value of the performance parameter deviates greatly from the sample performance parameter with an obvious concentration trend in the simulation, a part of the performance is discarded to bring the reference design value closer to the sample parameter value with smaller actual process fluctuation. At this time, although the performance will be reduced, the performance distribution will account for a larger proportion and the volatility will be smaller, which can greatly improve the production yield.

[0058] Furthermore, in the design method of the diffraction optical waveguide provided in the present application, the turning grating includes a plurality of turning sub-gratings, the height of the turning grating includes the height of each turning sub-grating, and the duty cycle of the turning grating includes the duty cycle of each turning sub-grating; and / or, the outcoupling grating includes a plurality of outcoupling sub-gratings, the height of the outcoupling grating includes the height of each outcoupling sub-grating, and the duty cycle of the outcoupling grating includes the duty cycle of each outcoupling sub-grating.

[0059] Exemplarily, the coupling-in grating is a slant tooth grating, the turning grating is a straight tooth grating and includes 3 turning sub-gratings, and the coupling-out grating is a straight tooth grating and includes 3 coupling-out sub-gratings. The target optimization parameter group includes: the height H1, duty cycle D1 and slant tooth angle θ of the coupling-in grating, the height H2, height H3, height H4, duty cycle D2, duty cycle D3 and duty cycle D4 of the turning grating, and the height H5, height H6, height H7, duty cycle D5, duty cycle D6 and duty cycle D7 of the coupling-out grating. The reference design values ​​of each target optimization parameter and the corresponding range of values ​​of the random fluctuation amount are shown in Table 1.

[0060] Table 1:

[0061]

[0062] refer to Figure 2-5 , Figure 2 A schematic diagram showing the distribution of efficiency samples corresponding to several sample parameter groups before the reference design value is adjusted; Figure 3 A schematic diagram showing the distribution of uniformity samples corresponding to several sample parameter groups before the reference design value is adjusted; Figure 4 A schematic diagram showing the distribution of efficiency samples corresponding to several sample parameter groups after the reference design value is adjusted; Figure 5 is a schematic diagram showing the distribution of uniformity samples corresponding to several sample parameter groups after the reference design value is adjusted. Figure 2 and Figure 4 The horizontal axis is the efficiency sample value, and the vertical axis is the number of sample parameter groups. The figure shows the number of sample parameter groups under each efficiency sample value; Figure 3 and Figure 5 The horizontal axis is the uniformity sample value, and the vertical axis is the number of sample parameter groups. The figure shows the number of sample parameter groups under each uniformity sample value.

[0063] Specifically, from Figure 2 It can be seen that the expected efficiency value represented by the red dotted line is about 177, and the mode of the efficiency sample before the reference design value adjustment is about 144. There is a certain deviation between the expected efficiency value and the mode of the efficiency sample. This result reflects that the optimal design value selected when designing the parameters does not have the best fluctuation stability. Therefore, when the actual production is carried out according to the design parameter value, the actual product performance may be generally low, resulting in a low yield problem. Similarly, from Figure 3 It can also be seen that the expected uniformity value represented by the red dotted line is about 0.33, and the mode of the uniformity sample before the reference design value is adjusted is about 0.27. There is also a certain deviation between the expected uniformity value and the mode of the uniformity sample. This result also reflects that the optimal design value selected when designing the parameters does not have the best fluctuation stability.

[0064] And from Figure 4 It can be seen that the efficiency sample after the reference design value is adjusted is basically consistent with the expected efficiency value represented by the red dotted line. Figure 5 It can also be seen that the uniformity sample after the reference design value is adjusted is basically consistent with the expected uniformity value represented by the red dotted line. Figure 2 and Figure 4 ,as well as Figure 3 and Figure 5 It can be seen that although the efficiency and uniformity will be reduced after the reference design value is adjusted, the performance distribution ratio will be larger and the volatility will be smaller, which can greatly improve the production yield.

[0065] In another embodiment, the design method of the diffractive optical waveguide may further include:

[0066] S50, after adding a random fluctuation amount to one of the target optimization parameters in the target optimization parameter group, a plurality of parameter evaluation groups are obtained, and a performance evaluation parameter fluctuation range corresponding to the target optimization parameter is obtained according to the performance evaluation parameters corresponding to each of the plurality of parameter evaluation groups;

[0067] S60, for each target optimization parameter corresponding to a performance evaluation parameter fluctuation interval, when the interval length is greater than a preset fluctuation interval, determining the corresponding target optimization parameter as a production feedback control parameter.

[0068] Specifically, when performing parameter impact analysis, the control variable method can also be used to add a random fluctuation amount to a certain target optimization parameter and then perform performance parameter fluctuation stability analysis, so that the impact of the target optimization parameter on the performance parameter fluctuation can be obtained. Figure 6 , the figure shows a schematic diagram of the fluctuation range of performance evaluation parameters corresponding to each target optimization parameter in a design method of a diffractive optical waveguide. The horizontal axis of the figure is the target optimization parameter, and the vertical axis is the performance evaluation parameter value. Each target optimization parameter corresponds to a vertical line segment, and the length of the vertical line segment represents the length of the fluctuation range of the performance evaluation parameter value. The longer the vertical line segment corresponding to the target optimization parameter, the greater the performance fluctuation when the target optimization parameter changes.

[0069] It can be understood that the actual process errors of the basic structural parameters in the production process are unavoidable. When the performance fluctuation range caused by the actual process errors of the basic structural parameters is within an acceptable range, there is no need to intervene in the corresponding actual process; when the performance fluctuation range caused by the actual process errors of the basic structural parameters exceeds the acceptable range, it is necessary to intervene in the corresponding actual process to control the actual process errors of the basic structural parameters. That is, in this embodiment, for the performance evaluation parameter fluctuation interval corresponding to each target optimization parameter, when the interval length is greater than the preset fluctuation interval, the corresponding target optimization parameter is determined as the production feedback control parameter, and the actual process error of the target optimization parameter needs to be focused on in the actual process.

[0070] Further practicably, adjusting the reference design value of the target optimization parameter group according to the sample parameter group also includes: preferentially adjusting the reference design value of the production feedback control parameter according to the sample parameter group.

[0071] Specifically, being determined as a production feedback control parameter indicates that the performance fluctuation caused by the actual process error of the production feedback control parameter is large, so it can also be given priority to adjust its reference design value during the front-end design.

[0072] In another embodiment, the coupled grating is a blazed grating; S30 includes: filtering out sample performance parameters corresponding to changes in grating tooth shape from the sample parameter group; determining the sample performance parameters corresponding to each of the filtered sample parameter groups, and screening out the mode of the sample performance parameters.

[0073] It can be understood that for some grating structures with special tooth shapes, such as blazed gratings, there will be certain constraints between the various target optimization parameters of the grating structure. When the sample parameter group is obtained by adding random fluctuations to the target optimization parameters, the sample parameter values ​​in the sample parameter group may not meet these constraints, resulting in changes in the grating tooth shape defined by the sample parameter group. At this time, it is necessary to filter out the sample parameter group corresponding to the change in the grating tooth shape from the sample parameter group, and then perform subsequent processing on the filtered sample parameter group to ensure the rationality and correctness of the analysis data.

[0074] On the other hand, the present application provides a diffraction optical waveguide, which includes at least a coupling-in grating and a coupling-out grating, wherein various grating parameters in the coupling-in grating and the coupling-out grating corresponding to the target optimization parameter group are designed according to the aforementioned design method of the diffraction optical waveguide.

[0075] In some embodiments, the diffraction optical waveguide further includes a turning grating, wherein various grating parameters in the turning grating corresponding to the target optimization parameter group are designed according to the aforementioned design method of the diffraction optical waveguide.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for designing a diffractive optical waveguide, wherein the diffractive optical waveguide comprises at least an incoupling grating and an outcoupling grating, characterized in that: The design method of the diffractive optical waveguide comprises: Selecting a target optimization parameter group from among various grating parameters in the coupling-in grating and the coupling-out grating, and obtaining reference design values ​​corresponding to various target optimization parameters in the target optimization parameter group, and expected values ​​of performance parameters corresponding to the target optimization parameter group; Acquire a plurality of sample parameter groups; wherein, after adding a random fluctuation amount to at least one of the target optimization parameters in each target optimization parameter group, a sample parameter group is obtained; and the value range of the random fluctuation amount corresponding to the target optimization parameter is determined according to the actual process error of the target optimization parameter; Determine sample performance parameters corresponding to each of the sample parameter groups, and screen out the mode of the sample performance parameters; When the difference between the mode and the expected value of the performance parameter exceeds a threshold, a sample parameter group corresponding to the mode is obtained, and a reference design value of the target optimization parameter group is adjusted according to the sample parameter group.

2. The design method of a diffractive optical waveguide according to claim 1, characterized in that: The coupling-in grating is a slant-tooth grating, and the coupling-out grating is a straight-tooth grating; the target optimization parameter group includes: the height, duty cycle and slant-tooth angle of the coupling-in grating; and the height and duty cycle of the coupling-out grating.

3. The design method of a diffractive optical waveguide according to claim 2, characterized in that: The diffraction optical waveguide further includes a turning grating, and the turning grating is a straight tooth grating; the target optimization parameter group further includes: the height and duty cycle of the turning grating.

4. The design method of a diffractive optical waveguide according to claim 3, characterized in that: The turning grating includes a plurality of turning sub-gratings, the height of the turning grating includes the height of each of the turning sub-gratings, and the duty cycle of the turning grating includes the duty cycle of each of the turning sub-gratings; and / or, the outcoupling grating includes a plurality of outcoupling sub-gratings, the height of the outcoupling grating includes the height of each of the outcoupling sub-gratings, and the duty cycle of the outcoupling grating includes the duty cycle of each of the outcoupling sub-gratings.

5. The design method of a diffractive optical waveguide according to claim 1, characterized in that: The actual process error of the target optimization parameter is related to the structure and material of the grating to which the target optimization parameter belongs and the production equipment used.

6. The design method of a diffractive optical waveguide according to claim 1, characterized in that: The expected performance parameter value includes an expected efficiency value and an expected uniformity value, and the sample performance parameter includes an efficiency sample and a uniformity sample; when the difference between the mode and the expected performance parameter value exceeds a threshold, obtaining a sample parameter group corresponding to the mode, and adjusting a reference design value of the target optimization parameter group according to the sample parameter group, including: When the difference between the mode of the efficiency samples and the expected efficiency value exceeds a threshold, and the difference between the mode of the uniformity samples and the expected uniformity value exceeds a threshold, respectively obtaining a sample parameter group corresponding to the mode of the efficiency samples and a sample parameter group corresponding to the mode of the uniformity samples; According to the proportion of the influence of the expected efficiency value and the expected uniformity value, based on the sample parameter groups corresponding to the mode of the efficiency samples and the mode of the uniformity samples, the reference design value of the target optimization parameter group is adjusted.

7. The design method of a diffractive optical waveguide according to claim 1, characterized in that: The design method of the diffractive optical waveguide also includes: After adding a random fluctuation amount to one of the target optimization parameters in the target optimization parameter group, a plurality of parameter evaluation groups are obtained, and according to the performance evaluation parameters corresponding to each of the plurality of parameter evaluation groups, a performance evaluation parameter fluctuation range corresponding to the target optimization parameter is obtained; For the performance evaluation parameter fluctuation interval corresponding to each of the target optimization parameters, when the interval length is greater than the preset fluctuation interval, the corresponding target optimization parameter is determined to be a production feedback control parameter.

8. The design method of a diffractive optical waveguide according to claim 7, characterized in that: The step of adjusting the reference design value of the target optimization parameter group according to the sample parameter group further includes: The reference design values ​​of the production feedback control parameters are preferentially adjusted according to the sample parameter group.

9. The design method of a diffractive optical waveguide according to claim 1, characterized in that: The coupling-in grating is a blazed grating; the determining of the sample performance parameters corresponding to each of the sample parameter groups and screening out the mode of the sample performance parameters comprises: Filtering out sample performance parameters corresponding to changes in grating tooth profile from the sample parameter group; The sample performance parameters corresponding to each of the filtered sample parameter groups are determined, and the mode of the sample performance parameters is screened out.

10. A diffractive optical waveguide, comprising at least an in-coupling grating and an out-coupling grating, characterized in that: The grating parameters corresponding to the target optimization parameter group in the coupling-in grating and the coupling-out grating are designed according to the design method of the diffraction optical waveguide according to any one of claims 1 to 9.

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