Binocular waveguide grating and preparation process thereof

Abstract

The invention provides a binocular waveguide grating and a preparation process thereof, and the preparation process comprises the steps: firstly, preparing a first out-coupling grating which is coupled to the left eye of a person for imaging on a waveguide substrate, then preparing an in-coupling grating on the waveguide substrate based on the first out-coupling grating, and further preparing a second out-coupling grating on the waveguide substrate based on the in-coupling grating. And preparing a second coupling-out grating for coupling out and imaging to the right eye of the person on the waveguide substrate based on the coupling-in grating. Binocular waveguide grating prepared by the binocular waveguide grating preparation process can realize that grating vectors coupled into the grating and grating vectors coupled out of the grating in an optical path transmission path for left eye imaging of a waveguide guide user form a closed loop and grating vectors coupled into the grating in an optical path transmission path for right eye imaging of the waveguide guide user are combined and coupled and the grating vector of the output grating forms a closed loop, so that the waveguide display imaging is undistorted compared with a projected image of an optical machine.

Description

Technical Field

[0001] The present invention belongs to the technical field of AR diffraction optical waveguides, and in particular relates to a binocular waveguide grating and a preparation process thereof. Background Art

[0002] Augmented Reality (AR) technology refers to the use of certain technical means to provide users with additional information in the real world (the so-called "enhancement"). This technology organically combines the images of the virtual world and the scenes of the real world, and deeply integrates the calculated information with the real world, thereby providing users with richer information and immersive experience.

[0003] Augmented reality technology can be implemented through many hardware platforms, among which the most immersive is wearable augmented reality devices, namely AR glasses. The hardware form of this method is a simple pair of glasses, which guide light into the human eye through the microstructure on the surface of the lens. This hardware implementation method is the most convenient and is the mainstream technology of AR. The purpose of AR glasses lenses is to guide the image from the imaging device through the lens into the human eye. The grating waveguide solution is a mainstream technical solution. The grating waveguide includes a waveguide substrate, an in-coupling grating and an out-coupling grating. The in-coupling grating and the out-coupling grating are set on the waveguide substrate. Its basic principle is as follows Figure 1 As shown, the projection light constituting the image projected by the optical machine is coupled into the grating and coupled into the waveguide substrate, and propagates in the waveguide substrate by total reflection. Whenever a part of the light encounters an out-coupling grating, the out-coupled light (the solid line in the direction of the human eye in the figure) enters the human eye, so that the human eye can see the same image as the output of the optical machine. At the same time, the human eye can see the real world scene (the dotted line in the direction of the human eye in the figure). The overlap of the two parts can realize the function of augmented reality.

[0004] An existing grating waveguide design scheme is to use a single-chip waveguide to make a grating to achieve a binocular imaging effect, that is, the projection light of the single-light machine is coupled into the coupling grating located in the middle area of ​​the waveguide, and is propagated through total reflection of the waveguide substrate and coupled out through the coupling gratings on both sides of the waveguide to achieve imaging at the user's eye position.

[0005] With respect to the grating waveguide design scheme for realizing binocular imaging effect with the above-mentioned single-chip waveguide, in order to ensure that the waveguide display imaging is distortion-free and distortion-free compared to the projected image of the optical machine, it is necessary to ensure that the grating vector of the coupled-in grating and the grating vector of the coupled-out grating in the optical path transmission path of the waveguide for the user's left-eye imaging form a closed loop, and to ensure that the grating vector of the coupled-in grating and the grating vector of the coupled-out grating in the optical path transmission path of the waveguide for the user's right-eye imaging form a closed loop.

[0006] Therefore, with regard to the grating waveguide design scheme for realizing binocular imaging effect by a single waveguide as mentioned above, how to realize that the grating vector of the input grating and the grating vector of the output grating in the optical path transmission path of the waveguide for imaging the user's left eye form a closed loop and the grating vector of the input grating and the grating vector of the output grating in the optical path transmission path of the waveguide for imaging the user's right eye form a closed loop has become a technical problem that urgently needs to be solved in this field. Summary of the invention

[0007] In order to overcome the defects of the prior art, the present invention provides a binocular waveguide grating and a preparation process thereof.

[0008] The present invention is achieved through the following technical solutions:

[0009] The present invention provides a binocular waveguide grating preparation process, comprising the following steps:

[0010] A first out-coupling grating is prepared on the waveguide substrate, wherein the first out-coupling grating out-couples an image to a person's left eye;

[0011] Based on the first out-coupling grating, preparing an in-coupling grating on a waveguide substrate;

[0012] Based on the coupling-in grating, a second coupling-out grating is prepared on a waveguide substrate, wherein the second coupling-out grating couples out an image to a person's right eye.

[0013] Furthermore, the first outcoupling grating adopts a first partitioned combined grating;

[0014] The first partitioned combined grating includes a first grating, a second grating and a third grating which are closely arranged;

[0015] The first grating is a one-dimensional grating, the second grating is a two-dimensional grating, and the third grating is a one-dimensional grating;

[0016] The second grating has the same grating lines and grating direction in the first dimension as the first grating, and the same grating lines and grating direction in the second dimension as the third grating.

[0017] Furthermore, the step of preparing the first outcoupling grating on the waveguide substrate comprises the following steps:

[0018] preparing a second grating and a first reference grating on a waveguide substrate, wherein the first reference grating replicates the second grating;

[0019] Based on the first reference grating, a first grating and a third grating are prepared on a waveguide substrate.

[0020] Furthermore, the step of preparing the second grating and the first reference grating on the waveguide substrate comprises the following steps:

[0021] Spin-coat a photoresist on the entire surface of the waveguide substrate to obtain a waveguide substrate provided with a photoresist mask;

[0022] A second reference grating is fixed in an exposure fixture of an exposure device, and the incident angle of two interfering light beams in the exposure device to the second reference grating is adjusted until the moiré fringe shape appearing in the space meets the required requirements. A waveguide substrate provided with a photoresist mask is placed on the exposure fixture in the adjusted exposure device according to a corresponding set angle, and a light beam interference exposure operation of a first-dimensional grating in the second grating and a light beam interference exposure operation of a second-dimensional grating in the second grating are performed on the photoresist mask on the waveguide substrate, so as to obtain a photoresist mask with changed properties on the waveguide substrate; wherein the second reference grating reproduces the second grating;

[0023] Performing a development operation on the photoresist mask with changed properties on the waveguide substrate to obtain a waveguide substrate with a photoresist grating mask;

[0024] Using an etching baffle to shield the waveguide substrate with the photoresist grating mask, so that the waveguide substrate with the photoresist grating mask is etched only in the area where the second grating is located and the area where the first reference grating is located, and the second grating and the first reference grating are obtained on the waveguide substrate;

[0025] Clean the remaining photoresist on the waveguide substrate.

[0026] Furthermore, based on the first reference grating, preparing a first grating and a third grating on a waveguide substrate comprises the following steps:

[0027] Spin-coat the entire surface of the waveguide substrate with photoresist, remove the photoresist on the waveguide substrate in the area where the first reference grating is located, and obtain the waveguide substrate with the photoresist mask set;

[0028] Placing the waveguide substrate provided with the photoresist mask on an exposure jig in an exposure device at a corresponding set angle, correspondingly adjusting the incident angles of the two interfering light beams in the exposure device to the first reference grating until the moiré fringe morphology appearing in the space meets the required requirements, and performing the light beam interference exposure operation of the first grating and the light beam interference exposure operation of the third grating on the photoresist mask on the waveguide substrate using the adjusted exposure device to obtain a photoresist mask with changed properties on the waveguide substrate;

[0029] Performing a development operation on the photoresist mask with changed properties on the waveguide substrate to obtain a waveguide substrate with a photoresist grating mask;

[0030] Using an etching baffle to shield the waveguide substrate with the photoresist grating mask, so that the waveguide substrate with the photoresist grating mask is etched only in the area where the first grating and the area where the third grating are located, and the first grating and the third grating are obtained on the waveguide substrate;

[0031] Clean the remaining photoresist on the waveguide substrate.

[0032] Furthermore, based on the first out-coupling grating, preparing an in-coupling grating on a waveguide substrate comprises the following steps:

[0033] Spin-coat the entire surface of the waveguide substrate with photoresist, remove the photoresist on the waveguide substrate in the area where the first reference grating is located, and obtain the waveguide substrate with the photoresist mask set;

[0034] Placing the waveguide substrate provided with the photoresist mask on an exposure jig in the exposure device at a set angle;

[0035] Adjusting the incident angles of the two interfering light beams in the exposure device to the first reference grating until the moiré fringe morphology appearing in the space meets the required requirements;

[0036] Using the adjusted exposure equipment to perform a light beam interference exposure operation coupled into the grating on the photoresist mask on the waveguide substrate, so as to obtain a photoresist mask with changed properties on the waveguide substrate;

[0037] Performing a development operation on the photoresist mask with changed properties on the waveguide substrate to obtain a waveguide substrate with a photoresist grating mask;

[0038] Using an etching baffle to shield the waveguide substrate with the photoresist grating mask, so that the waveguide substrate with the photoresist grating mask is etched only in the area where the coupling grating is located and the area where the third reference grating is located, and the coupling grating and the third reference grating are obtained on the waveguide substrate, wherein the third reference grating replicates the coupling grating;

[0039] Clean the remaining photoresist on the waveguide substrate.

[0040] Furthermore, the second outcoupling grating adopts a second partitioned combined grating;

[0041] The second subarea combined grating includes a fourth grating, a fifth grating and a sixth grating which are closely arranged;

[0042] The fourth grating is a one-dimensional grating, the fifth grating is a two-dimensional grating, and the sixth grating is a one-dimensional grating;

[0043] The fifth grating has the same grating lines and grating direction of the first-dimensional grating as the fourth grating, and the fifth grating has the same grating lines and grating direction of the second-dimensional grating as the sixth grating.

[0044] Furthermore, based on the coupling-in grating, preparing a second coupling-out grating on a waveguide substrate comprises the following steps:

[0045] preparing a fifth grating and a fourth reference grating on a waveguide substrate, wherein the fourth reference grating replicates the fifth grating;

[0046] Based on the fourth reference grating, a fourth grating and a sixth grating are prepared on a waveguide substrate.

[0047] Furthermore, the step of preparing the fifth grating and the fourth reference grating on the waveguide substrate comprises the following steps:

[0048] Spin-coating photoresist on the entire surface of the waveguide substrate to obtain a waveguide substrate provided with a first photoresist mask;

[0049] Using the fifth reference grating to adjust the exposure device, and using the adjusted exposure device to perform a light beam interference exposure operation of the first dimension grating in the fifth grating on the first photoresist mask on the waveguide substrate, so as to obtain a first photoresist mask with changed properties on the waveguide substrate;

[0050] Performing a first development operation on the first photoresist mask with changed properties on the waveguide substrate in the region where the third reference grating is located, to obtain a waveguide substrate having a photoresist grating mask in the region where the third reference grating is located;

[0051] Using the photoresist grating mask of the waveguide substrate in the area where the third reference grating is located to adjust the exposure equipment, using the adjusted exposure equipment to perform a beam interference exposure operation of the second dimension grating in the fifth grating on the waveguide substrate having the photoresist grating mask in the area where the third reference grating is located, to obtain a second photoresist mask with changed properties on the waveguide substrate;

[0052] Performing a development operation on the second photoresist mask with changed properties on the waveguide substrate to obtain a waveguide substrate having a second photoresist grating mask;

[0053] Using an etching baffle to shield the waveguide substrate having the second photoresist grating mask, so that the waveguide substrate having the photoresist grating mask is etched only in the area where the fifth grating is located and the area where the fourth reference grating is located, and the fifth grating and the fourth reference grating are obtained on the waveguide substrate;

[0054] Clean the remaining photoresist on the waveguide substrate.

[0055] Furthermore, based on the fourth reference grating, preparing a fourth grating and a sixth grating on a waveguide substrate comprises the following steps:

[0056] Spin-coat the entire surface of the waveguide substrate with photoresist, remove the photoresist on the waveguide substrate in the area where the fourth reference grating is located, and obtain the waveguide substrate with the photoresist mask set;

[0057] Placing the waveguide substrate provided with the photoresist mask on an exposure fixture in an exposure device at a corresponding set angle, correspondingly adjusting the incident angles of the two interfering light beams in the exposure device to the fourth reference grating until the moiré fringe morphology appearing in the space meets the required requirements, and performing the light beam interference exposure operation of the fourth grating and the light beam interference exposure operation of the sixth grating on the photoresist mask on the waveguide substrate using the adjusted exposure device to obtain a photoresist mask with changed properties on the waveguide substrate;

[0058] Performing a development operation on the photoresist mask with changed properties on the waveguide substrate to obtain a waveguide substrate with a photoresist grating mask;

[0059] Using an etching baffle to shield the waveguide substrate with the photoresist grating mask, so that the waveguide substrate with the photoresist grating mask is etched only in the area where the fourth grating and the area where the sixth grating are located, and the fourth grating and the sixth grating are obtained on the waveguide substrate;

[0060] Clean the remaining photoresist on the waveguide substrate.

[0061] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0062] The present invention provides a binocular waveguide grating preparation process, first, a first out-coupling grating for out-coupling imaging to a person's left eye is prepared on a waveguide substrate, then a coupling-in grating is prepared on the waveguide substrate based on the first out-coupling grating, and then a second out-coupling grating for out-coupling imaging to a person's right eye is prepared on the waveguide substrate based on the coupling-in grating. The binocular waveguide grating prepared by the above binocular waveguide grating preparation process can realize that the grating vector of the coupling-in grating and the grating vector of the coupling-out grating in the optical path transmission path of the waveguide for imaging the user's left eye form a closed loop, and the grating vector of the coupling-in grating and the grating vector of the coupling-out grating in the optical path transmission path of the waveguide for imaging the user's right eye form a closed loop, thereby ensuring that the waveguide display imaging is distortion-free and distortion-free compared to the projected image of the optical machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 paying creative labor.

[0064] Figure 1 This is a schematic diagram of the basic principle of the grating waveguide solution;

[0065] Figure 2 A schematic diagram of a grating vector for an example one-dimensional grating;

[0066] Figure 3 A schematic diagram of a grating vector of an example two-dimensional grating;

[0067] Figure 4 A schematic diagram of k-space design of an existing grating waveguide is shown as an example;

[0068] Figure 5 A schematic diagram of the grating layout of a waveguide substrate in the process of preparing a binocular waveguide grating of the present invention;

[0069] Figure 6 The figure is a schematic diagram of a binocular waveguide grating structure prepared by the binocular waveguide grating preparation process of the present invention.

[0070] Among them, 1-first out-coupling grating, 1-1-first grating, 1-2-second grating, 1-3-third grating, 2-in-coupling grating, 3-second out-coupling grating, 3-1-fourth grating, 3-2-fifth grating, 3-3-sixth grating, 4-waveguide substrate, 5-first reference grating, 6-third reference grating, 7-fourth reference grating. DETAILED DESCRIPTION

[0071] The technical solution of the present invention will be clearly and completely described below in conjunction with 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 are within the scope of protection of the present invention.

[0072] In this article, the terms "first", "second" and other similar words are not intended to imply any order, quantity and importance, but are only used to distinguish different elements. In this article, the terms "one", "an" and other similar words are not intended to indicate that there is only one of the things described, but rather indicate that the relevant description is only for one of the things described, and the things described may have one or more. In this article, the terms "comprise", "include" and other similar words are intended to indicate logical mutual relationships, and cannot be regarded as indicating spatial structural relationships. For example, "A includes B" is intended to indicate that B belongs to A logically, but does not indicate that B is located inside A spatially. In addition, the meanings of the terms "comprise", "include" and other similar words should be regarded as open, rather than closed. For example, "A includes B" is intended to indicate that B belongs to A, but B does not necessarily constitute the whole of A, and A may also include other elements such as C, D, and E.

[0073] In this document, the terms "embodiment", "present embodiment", "preferred embodiment", and "one embodiment" do not mean that the relevant description is only applicable to a specific embodiment, but rather that the description may also be applicable to one or more other embodiments. Those skilled in the art should understand that in this document, any description of a certain embodiment can be replaced, combined, or combined in other ways with the relevant description in one or more other embodiments, and the new embodiment generated by the replacement, combination, or combination in other ways is easily conceivable by those skilled in the art and falls within the scope of protection of the present invention.

[0074] In the description herein, “plurality” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0075] Rasters have raster vectors, such as

[0076] For a one-dimensional grating, Figure 2 As shown, for example, there is a grating vector, the size of the grating vector is related to the grating period (K = 2π / d, where K represents the size of the grating vector of the one-dimensional grating and d is the period of the one-dimensional grating), and the direction of the grating vector is perpendicular to the grating line direction of the one-dimensional grating.

[0077] For a two-dimensional grating, such as Figure 3 As shown, exemplarily, there are two grating vectors (a first grating vector and a second grating vector), the size of the first grating vector is K1=2π / d1 / sin(a), and the size of the second grating vector is K2=2π / d2 / sin(a). The direction of the first grating vector is perpendicular to the grating line direction of the second dimension grating (grating period is d2), and the direction of the second grating vector is perpendicular to the grating line direction of the first dimension grating (grating period is d1), wherein d1 is the grating period of the first dimension grating, d2 is the grating period of the second dimension grating, and a is the angle between the grating line direction of the first dimension grating and the grating line direction of the second dimension grating.

[0078] like Figure 4 As shown, it is a schematic diagram of the k-space design of an existing grating waveguide as an example. The rectangular box in the figure represents the in-plane component box of the k-vector of the FOV projected by the optical machine on the waveguide plane. The inner circular surface represents the projection of the K-vector on the waveguide plane in all possible propagation states of light when it propagates in the air. The outer circular surface represents the projection of the K-vector on the waveguide plane in all possible propagation states of light when it propagates in a waveguide medium with a refractive index of n. The in-plane component of the k-vector representing the FOV of the optomechanical projection in the waveguide plane (usually it is approximated by a rectangular box), is the grating vector coupled into the grating, and are the two grating vectors of the outcoupling grating (where Represents the raster vector size, d t is the grating period, where t=Gin, 1, 2).

[0079] As shown in the figure, when the following three conditions (1)-(3) are all met, the propagation direction of the modulated light beam inside the waveguide substrate meets the total reflection condition:

[0080]

[0081] and These three grating vectors form two closed loops in k-space.

[0082] Existing technology or solutions will and The purpose of these three k-vectors forming two closed loops in k-space is to ensure that the FOV projected by the optical machine will eventually return to its original state after being acted upon by the grating vectors of the coupling-in grating and the coupling-out grating when the grating waveguide is used as an AR glasses lens. That is, when the projected image of the optical machine enters the eye box in the form of a projected light beam through the coupling-in grating coupling-in waveguide and the coupling-out grating coupling-out waveguide, the waveguide display imaging is distortion-free and non-distorted compared to the projected image of the optical machine.

[0083] As for the grating waveguide design scheme for achieving binocular imaging effect with a single waveguide, how to achieve a closed loop formed by the grating vector coupled into the grating and the grating vector coupled out of the grating in the optical path transmission path of the waveguide for imaging the user's left eye and a closed loop formed by the grating vector coupled into the grating and the grating vector coupled out of the grating in the optical path transmission path of the waveguide for imaging the user's right eye has become a technical problem that urgently needs to be solved in this field.

[0084] Therefore, the present invention provides a binocular waveguide grating preparation process, the overall concept is as follows:

[0085] S1 prepares a first out-coupling grating on a waveguide substrate, wherein the first out-coupling grating couples out an image to a person's left eye.

[0086] For example, Figure 5 As shown, the first outcoupling grating 1 adopts a first partition combination grating.

[0087] Exemplarily, the first partitioned combined grating includes a first grating 1-1, a second grating 1-2, and a third grating 1-3 which are closely arranged.

[0088] The first grating 1-1 is a one-dimensional grating, the second grating 1-2 is a two-dimensional grating, and the third grating 1-3 is a one-dimensional grating. The second grating 1-2 has the same grating lines and grating direction in the first dimension as the first grating 1-1, and the second grating 1-2 has the same grating lines and grating direction in the second dimension as the third grating 1-3.

[0089] S2 prepares a coupling-in grating on a waveguide substrate based on the first coupling-out grating.

[0090] For example, Figure 5 As shown, the coupling-in grating 2 is a one-dimensional grating.

[0091] S3 prepares a second out-coupling grating on a waveguide substrate based on the in-coupling grating, wherein the second out-coupling grating out-couples an image to a person's right eye.

[0092] For example, Figure 5 As shown, the second outcoupling grating 3 adopts a second partition combination grating.

[0093] Exemplarily, the second partitioned combined grating includes a fourth grating 3-1, a fifth grating 3-2 and a sixth grating 3-3 which are closely arranged.

[0094] The fourth grating 3-1 is a one-dimensional grating, the fifth grating 3-2 is a two-dimensional grating, and the sixth grating 3-3 is a one-dimensional grating. The grating lines and grating direction of the first dimension grating of the fifth grating 3-2 are the same as those of the fourth grating 3-1, and the grating lines and grating direction of the second dimension grating of the fifth grating 3-2 are the same as those of the sixth grating 3-3.

[0095] Exemplarily, the above-mentioned preparation of the first outcoupling grating on the waveguide substrate generally includes the following steps:

[0096] S1-1 prepares the second grating 1-2 and the first reference grating 5 (such as Figure 5 ), where the first reference grating 5 replicates the second grating 1-2.

[0097] The following are some examples:

[0098] S1-1-1 Spin-coat photoresist on the entire surface of the waveguide substrate to obtain a waveguide substrate with a photoresist mask.

[0099] The photoresist here can be a positive photoresist or a negative photoresist.

[0100] S1-1-2 fix the second reference grating in the exposure jig of the exposure equipment, adjust the incident angle of the two interfering light beams in the exposure equipment to the second reference grating until the moiré fringe shape appearing in the space meets the required requirements, place the waveguide substrate with the photoresist mask set on the exposure jig in the adjusted exposure equipment according to the corresponding set angle, and perform the beam interference exposure operation of the first dimension grating in the second grating and the beam interference exposure operation of the second dimension grating in the second grating on the photoresist mask on the waveguide substrate, so as to obtain a photoresist mask with changed properties on the waveguide substrate; wherein the second reference grating reproduces the second grating.

[0101] The second reference grating here can adopt a first dimension reference grating and a second dimension reference grating, wherein the first dimension reference grating is the same as the first dimension grating in the second grating, and the second dimension reference grating is the same as the second dimension grating in the second grating.

[0102] Taking the second reference grating using the first dimension reference grating and the second dimension reference grating as an example, the specific steps include:

[0103] The first dimensional reference grating is fixed in an exposure jig of the exposure device, and the incident angle of the two interfering light beams in the exposure device to the first dimensional reference grating is adjusted until the moiré fringe pattern appearing in the space is sparse (generally, two moiré fringes appear), and the waveguide substrate with the photoresist mask is placed on the exposure jig in the adjusted exposure device at a set angle (corresponding to the grating line direction of the first dimensional grating in the second grating), so as to realize the light beam interference exposure operation of the first dimensional grating in the second grating on the photoresist mask on the waveguide substrate.

[0104] The second dimension reference grating is fixed in the exposure jig of the exposure equipment, and the incident angle of the two interfering light beams in the exposure equipment to the second dimension reference grating is adjusted until the moiré fringe pattern appearing in the space is sparse (generally two moiré fringes are sufficient) and meets the required requirements, and the waveguide substrate with the photoresist mask is placed on the exposure jig in the adjusted exposure equipment at a set angle (corresponding to the grating line direction of the second dimension grating in the second grating), so as to realize the light beam interference exposure operation of the second dimension grating in the second grating on the photoresist mask on the waveguide substrate.

[0105] After the above two interference exposure operations, a photoresist mask with changed properties is obtained on the waveguide substrate.

[0106] S1-1-3 performs a developing operation on the photoresist mask with changed properties on the waveguide substrate to obtain a waveguide substrate with a photoresist grating mask.

[0107] Taking positive photoresist as an example,

[0108] After the entire photoresist mask with changed properties on the waveguide substrate is immersed in a developer for development, the illuminated portion of the photoresist mask is corroded and dissolved by the developer to obtain a waveguide substrate with a photoresist grating mask.

[0109] S1-1-4 uses an etching baffle to block the waveguide substrate with the photoresist grating mask, so that the waveguide substrate with the photoresist grating mask is only etched in the area where the second grating is located and the area where the first reference grating is located, and the second grating and the first reference grating are obtained on the waveguide substrate.

[0110] An ion beam etcher is used to etch a substrate having a photoresist grating mask. During the etching process, an etching baffle is used to shield the waveguide substrate having the photoresist grating mask, so that the waveguide substrate having the photoresist grating mask is etched by the ion beam etcher only in the area where the second grating and the area where the first reference grating are located, thereby obtaining the second grating and the first reference grating on the waveguide substrate.

[0111] S1-1-5 cleans the remaining photoresist on the waveguide substrate.

[0112] For example, acetone reagent may be used to clean the remaining photoresist on the waveguide substrate.

[0113] S1-2 Based on the first reference grating 5, a first grating 1-1 and a third grating 1-3 (such as Figure 5 shown).

[0114] The following are some examples:

[0115] S1-2-1 spin-coats photoresist on the entire surface of the waveguide substrate, removes the photoresist on the waveguide substrate in the area where the first reference grating is located, and obtains a waveguide substrate with a photoresist mask.

[0116] The photoresist on the waveguide substrate in the area where the first reference grating is located can be removed by wiping with an acetone reagent.

[0117] S1-2-2 places the waveguide substrate with the photoresist mask on the exposure jig in the exposure equipment at a corresponding set angle, and correspondingly adjusts the incident angles of the two interfering light beams in the exposure equipment to the first reference grating until the moiré fringe shape appearing in the space meets the required requirements, and uses the adjusted exposure equipment to perform the light beam interference exposure operation of the first grating and the light beam interference exposure operation of the third grating on the photoresist mask on the waveguide substrate to obtain a photoresist mask with changed properties on the waveguide substrate.

[0118] For specific examples,

[0119] The waveguide substrate with a photoresist mask is placed on an exposure jig in an exposure device at a set angle (corresponding to the grating line direction of the first grating), and the incident angle of the two interfering light beams in the exposure device to the first reference grating is adjusted until the moiré fringe pattern appearing in the space is sparse (generally two moiré fringes are sufficient), and the adjusted exposure device is used to perform the light beam interference exposure operation of the first grating on the photoresist mask on the waveguide substrate.

[0120] The waveguide substrate with a photoresist mask is placed on an exposure jig in an exposure device at a set angle (corresponding to the grating line direction of the third grating), and the incident angle of the two interfering light beams in the exposure device to the first reference grating is adjusted until the moiré fringe pattern appearing in the space is sparse (generally two moiré fringes are sufficient), and the adjusted exposure device is used to perform the beam interference exposure operation of the third grating on the photoresist mask on the waveguide substrate.

[0121] After the above two interference exposure operations, a photoresist mask with changed properties is obtained on the waveguide substrate.

[0122] S1-2-3 performs a developing operation on the photoresist mask with changed properties on the waveguide substrate to obtain a waveguide substrate with a photoresist grating mask.

[0123] Taking positive photoresist as an example,

[0124] After the entire photoresist mask with changed properties on the waveguide substrate is immersed in a developer for development, the illuminated portion of the photoresist mask is corroded and dissolved by the developer to obtain a waveguide substrate with a photoresist grating mask.

[0125] S1-2-4 uses an etching baffle to block the waveguide substrate with the photoresist grating mask, so that the waveguide substrate with the photoresist grating mask is etched only in the area where the first grating and the area where the third grating are located, and the first grating and the third grating are obtained on the waveguide substrate.

[0126] An ion beam etcher is used to etch a waveguide substrate having a photoresist grating mask. During the etching process, an etching baffle is used to shield the waveguide substrate having the photoresist grating mask, so that the waveguide substrate having the photoresist grating mask is etched by the ion beam etcher only in the area where the first grating and the area where the third grating are located, thereby obtaining the first grating and the third grating on the waveguide substrate.

[0127] S1-2-5 cleans the remaining photoresist on the waveguide substrate.

[0128] For example, acetone reagent may be used to clean the remaining photoresist on the waveguide substrate.

[0129] Exemplarily, based on the first out-coupling grating, the in-coupling grating 2 (such as Figure 5 The example includes the following steps:

[0130] S2-1 spin-coats photoresist on the entire surface of the waveguide substrate, removes the photoresist on the waveguide substrate in the area where the first reference grating is located, and obtains a waveguide substrate with a photoresist mask.

[0131] The photoresist on the waveguide substrate in the area where the first reference grating is located can be removed by wiping with an acetone reagent.

[0132] S2-2 places the waveguide substrate with the photoresist mask on an exposure jig in the exposure equipment at a set angle.

[0133] Here, the setting angle at which the waveguide substrate of the photoresist mask is placed on the exposure fixture in the exposure device corresponds to the direction of the grating lines of the coupled grating.

[0134] S2-3 adjusts the incident angle of the two interfering light beams in the exposure device to the first reference grating until the moiré fringe morphology appearing in the space meets the required requirements.

[0135] The incident angles of the two interfering light beams in the exposure device to the first reference grating are adjusted until the moiré fringes appearing in the space are sparse (generally, two moiré fringes are sufficient).

[0136] S2-4 uses the adjusted exposure equipment to perform a beam interference exposure operation coupled to the grating on the photoresist mask on the waveguide substrate, so as to obtain a photoresist mask with changed properties on the waveguide substrate.

[0137] S2-5: developing the photoresist mask with changed properties on the waveguide substrate to obtain a waveguide substrate with a photoresist grating mask.

[0138] Taking positive photoresist as an example,

[0139] After the entire photoresist mask with changed properties on the waveguide substrate is immersed in a developer for development, the illuminated portion of the photoresist mask is corroded and dissolved by the developer to obtain a waveguide substrate with a photoresist grating mask.

[0140] S2-6 uses an etching baffle to shield the waveguide substrate with the photoresist grating mask, so that the waveguide substrate with the photoresist grating mask is only etched in the area where the coupling grating and the third reference grating are located, and the coupling grating and the third reference grating 6 (such as Figure 5 As shown), wherein the third reference grating 6 replicates the coupling-in grating 2.

[0141] An ion beam etcher is used to etch a waveguide substrate having a photoresist grating mask. During the etching process, an etching baffle is used to shield the waveguide substrate having the photoresist grating mask, so that the waveguide substrate having the photoresist grating mask is etched by the ion beam etcher only in the area where the coupling grating and the area where the third reference grating are located, thereby obtaining the coupling grating and the third reference grating on the waveguide substrate.

[0142] S2-7 cleans the remaining photoresist on the waveguide substrate.

[0143] For example, acetone reagent may be used to clean the remaining photoresist on the waveguide substrate.

[0144] Exemplarily, the above-mentioned method of preparing a second out-coupling grating on a waveguide substrate based on an in-coupling grating generally includes the following steps:

[0145] S3-1 prepares the fifth grating 3-2 and the fourth reference grating 7 (such as Figure 5 As shown), wherein the fourth reference grating 7 replicates the fifth grating 3-2.

[0146] The following are some examples:

[0147] S3-1-1 Spin-coat photoresist on the entire surface of the waveguide substrate to obtain a waveguide substrate with a first photoresist mask.

[0148] The photoresist here can be a positive photoresist or a negative photoresist.

[0149] S3-1-2 uses the fifth reference grating to adjust the exposure equipment, and uses the adjusted exposure equipment to perform a beam interference exposure operation of the first dimension grating in the fifth grating on the first photoresist mask on the waveguide substrate, so as to obtain a first photoresist mask with changed properties on the waveguide substrate.

[0150] Specifically,

[0151] The fifth reference grating is fixed on the exposure fixture in the exposure device, and the incident angle of the two interfering light beams in the exposure device to the fifth reference grating is adjusted until the moiré fringe shape appearing in the space meets the required requirements (the moiré fringes are sparse, generally two moiré fringes appear), wherein the fifth reference grating reproduces the first dimension grating in the fifth grating.

[0152] The photoresist is spin-coated on the entire surface of the waveguide substrate to obtain a waveguide substrate provided with a first photoresist mask.

[0153] The waveguide substrate provided with the first photoresist mask is placed on an exposure jig in the adjusted exposure device at a set angle (corresponding to the grating line direction of the first dimension grating in the fifth grating).

[0154] The adjusted exposure equipment is used to perform a light beam interference exposure operation of the first dimension grating in the fifth grating on the first photoresist mask on the waveguide substrate, so as to obtain a first photoresist mask with changed properties on the waveguide substrate.

[0155] S3-1-3: Perform a first development operation on the first photoresist mask whose properties have been changed on the waveguide substrate in the area where the third reference grating is located, to obtain a waveguide substrate having a photoresist grating mask in the area where the third reference grating is located.

[0156] Taking positive photoresist as an example,

[0157] After the first photoresist mask whose properties have been changed on the waveguide substrate is immersed in a developer for development, the illuminated part of the photoresist mask in the area where the third reference grating is located is corroded and dissolved by the developer, thereby obtaining a waveguide substrate with a photoresist grating mask in the area where the third reference grating is located.

[0158] S3-1-4 uses the photoresist grating mask of the waveguide substrate in the area where the third reference grating is located to adjust the exposure equipment, and uses the adjusted exposure equipment to perform a beam interference exposure operation of the second dimension grating in the fifth grating on the waveguide substrate having the photoresist grating mask in the area where the third reference grating is located, to obtain a second photoresist mask with changed properties on the waveguide substrate.

[0159] The waveguide substrate having a photoresist grating mask in the area where the third reference grating is located is placed on an exposure jig in the exposure device at a set angle (corresponding to the grating line direction of the second dimension grating in the fifth grating).

[0160] Adjust the incident angle of the two interfering light beams in the exposure device to the photoresist grating mask in the area where the third reference grating is located until the moiré fringe shape appearing in the space meets the required requirements (the moiré fringes are sparse, and generally two moiré fringes are sufficient), and use the adjusted exposure device to perform a light beam interference exposure operation of the second dimension grating in the fifth grating on the waveguide substrate with the photoresist grating mask in the area where the third reference grating is located, and obtain a second photoresist mask with changed properties on the waveguide substrate.

[0161] S3-1-5 performs a developing operation on the second photoresist mask with changed properties on the waveguide substrate to obtain a waveguide substrate with a second photoresist grating mask.

[0162] Taking positive photoresist as an example,

[0163] After the entire photoresist mask with changed properties on the waveguide substrate is immersed in a developer for development, the illuminated portion of the photoresist mask is corroded and dissolved by the developer, thereby obtaining a waveguide substrate with a second photoresist grating mask.

[0164] S3-1-6 uses an etching baffle to block the waveguide substrate having the second photoresist grating mask, so that the waveguide substrate having the photoresist grating mask is etched only in the area where the fifth grating and the area where the fourth reference grating are located, and the fifth grating and the fourth reference grating are obtained on the waveguide substrate.

[0165] An ion beam etcher is used to etch a waveguide substrate having a photoresist grating mask. During the etching process, an etching baffle is used to shield the waveguide substrate having the photoresist grating mask, so that the waveguide substrate having the photoresist grating mask is etched by the ion beam etcher only in the area where the fifth grating and the area where the fourth reference grating are located, thereby obtaining the fifth grating and the fourth reference grating on the waveguide substrate.

[0166] S3-1-7 cleans the remaining photoresist on the waveguide substrate.

[0167] For example, acetone reagent may be used to clean the remaining photoresist on the waveguide substrate.

[0168] S3-2 Based on the fourth reference grating 7, a fourth grating 3-1 and a sixth grating 3-3 (such as Figure 5 shown).

[0169] The following are some examples:

[0170] S3-2-1 spin-coat the entire surface of the waveguide substrate with photoresist, remove the photoresist on the waveguide substrate in the area where the fourth reference grating is located, and obtain a waveguide substrate with a photoresist mask set;

[0171] The photoresist on the waveguide substrate in the area where the fourth reference grating is located can be removed by wiping with an acetone reagent.

[0172] S3-2-2 Place the waveguide substrate with the photoresist mask on the exposure jig in the exposure equipment at the corresponding set angle, and correspondingly adjust the incident angles of the two interfering light beams in the exposure equipment to the fourth reference grating until the moiré fringe shape appearing in the space meets the required requirements, and use the adjusted exposure equipment to perform the light beam interference exposure operation of the fourth grating and the light beam interference exposure operation of the sixth grating on the photoresist mask on the waveguide substrate to obtain a photoresist mask with changed properties on the waveguide substrate.

[0173] For specific examples,

[0174] The waveguide substrate with a photoresist mask is placed on an exposure jig in an exposure device at a set angle (corresponding to the grating line direction of the fourth grating), and the incident angle of the two interfering light beams in the exposure device to the fourth reference grating is adjusted until the moiré fringe pattern appearing in the space is sparse (generally two moiré fringes are sufficient), and the adjusted exposure device is used to perform the light beam interference exposure operation of the fourth grating on the photoresist mask on the waveguide substrate.

[0175] The waveguide substrate with a photoresist mask is placed on an exposure jig in an exposure device at a set angle (corresponding to the grating line direction of the sixth grating), and the incident angle of the two interfering light beams in the exposure device to the fourth reference grating is adjusted until the moiré fringe pattern appearing in the space is sparse (generally two moiré fringes are sufficient), and the adjusted exposure device is used to perform the beam interference exposure operation of the sixth grating on the photoresist mask on the waveguide substrate.

[0176] After the above two interference exposure operations, a photoresist mask with changed properties is obtained on the waveguide substrate.

[0177] S3-2-3: Performing a development operation on the photoresist mask with changed properties on the waveguide substrate to obtain a waveguide substrate with a photoresist grating mask.

[0178] Taking positive photoresist as an example,

[0179] After the entire photoresist mask with changed properties on the waveguide substrate is immersed in a developer for development, the illuminated portion of the photoresist mask is corroded and dissolved by the developer to obtain a waveguide substrate with a photoresist grating mask.

[0180] S3-2-4 uses an etching baffle to block the waveguide substrate with the photoresist grating mask, so that the waveguide substrate with the photoresist grating mask is etched only in the area where the fourth grating and the area where the sixth grating are located, and the fourth grating and the sixth grating are obtained on the waveguide substrate.

[0181] An ion beam etcher is used to etch a waveguide substrate having a photoresist grating mask. During the etching process, an etching baffle is used to shield the waveguide substrate having the photoresist grating mask, so that the waveguide substrate having the photoresist grating mask is etched by the ion beam etcher only in the area where the fourth grating and the area where the sixth grating are located, thereby obtaining the fourth grating and the sixth grating on the waveguide substrate.

[0182] S3-2-5 cleans the remaining photoresist on the waveguide substrate.

[0183] For example, acetone reagent may be used to clean the remaining photoresist on the waveguide substrate.

[0184] The present invention also provides a binocular waveguide grating, which is prepared by the above-mentioned binocular waveguide grating preparation process, such as Figure 6 As shown, the binocular waveguide grating includes an in-coupling grating 2 , a first out-coupling grating 1 and a second out-coupling grating 3 arranged on a waveguide substrate 4 .

[0185] The coupling grating 2 is a one-dimensional grating.

[0186] The first outcoupling grating 1 adopts a first partition combination grating.

[0187] The first partitioned combined grating includes a first grating 1-1, a second grating 1-2 and a third grating 1-3 which are closely arranged.

[0188] The first grating 1-1 is a one-dimensional grating, the second grating 1-2 is a two-dimensional grating, and the third grating 1-3 is a one-dimensional grating. The second grating 1-2 has the same grating lines and grating direction in the first dimension as the first grating 1-1, and the second grating 1-2 has the same grating lines and grating direction in the second dimension as the third grating 1-3.

[0189] The second outcoupling grating 3 adopts a second partition combination grating.

[0190] The second subarea combined grating includes a fourth grating 3-1, a fifth grating 3-2 and a sixth grating 3-3 which are closely arranged.

[0191] The fourth grating 3-1 is a one-dimensional grating, the fifth grating 3-2 is a two-dimensional grating, and the sixth grating 3-3 is a one-dimensional grating. The grating lines and grating direction of the first dimension grating of the fifth grating 3-2 are the same as those of the fourth grating 3-1, and the grating lines and grating direction of the second dimension grating of the fifth grating 3-2 are the same as those of the sixth grating 3-3.

[0192] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art can still modify or make equivalent substitutions to the specific implementations of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are within the scope of protection of the claims of the present invention to be approved.

Claims

1. A binocular waveguide grating preparation process, characterized in that: The steps include: A first out-coupling grating is prepared on the waveguide substrate, wherein the first out-coupling grating out-couples an image to a person's left eye; Based on the first out-coupling grating, preparing an in-coupling grating on a waveguide substrate; Based on the coupling-in grating, a second coupling-out grating is prepared on a waveguide substrate, wherein the second coupling-out grating couples out an image to a person's right eye.

2. The binocular waveguide grating preparation process according to claim 1, characterized in that: The first outcoupling grating adopts a first partitioned combined grating; The first partitioned combined grating includes a first grating, a second grating and a third grating which are closely arranged; The first grating is a one-dimensional grating, the second grating is a two-dimensional grating, and the third grating is a one-dimensional grating; The second grating has the same grating lines and grating direction in the first dimension as the first grating, and the same grating lines and grating direction in the second dimension as the third grating.

3. The binocular waveguide grating preparation process according to claim 2, characterized in that: The step of preparing a first outcoupling grating on a waveguide substrate comprises the following steps: preparing a second grating and a first reference grating on a waveguide substrate, wherein the first reference grating replicates the second grating; Based on the first reference grating, a first grating and a third grating are prepared on a waveguide substrate.

4. The binocular waveguide grating preparation process according to claim 3, characterized in that: The step of preparing the second grating and the first reference grating on the waveguide substrate comprises the following steps: Spin-coat a photoresist on the entire surface of the waveguide substrate to obtain a waveguide substrate provided with a photoresist mask; A second reference grating is fixed in an exposure fixture of an exposure device, and the incident angle of two interfering light beams in the exposure device to the second reference grating is adjusted until the moiré fringe shape appearing in the space meets the required requirements. A waveguide substrate provided with a photoresist mask is placed on the exposure fixture in the adjusted exposure device according to a corresponding set angle, and a light beam interference exposure operation of a first-dimensional grating in the second grating and a light beam interference exposure operation of a second-dimensional grating in the second grating are performed on the photoresist mask on the waveguide substrate, so as to obtain a photoresist mask with changed properties on the waveguide substrate; wherein the second reference grating reproduces the second grating; Performing a development operation on the photoresist mask with changed properties on the waveguide substrate to obtain a waveguide substrate with a photoresist grating mask; Using an etching baffle to shield the waveguide substrate with the photoresist grating mask, so that the waveguide substrate with the photoresist grating mask is etched only in the area where the second grating is located and the area where the first reference grating is located, and the second grating and the first reference grating are obtained on the waveguide substrate; Clean the remaining photoresist on the waveguide substrate.

5. The binocular waveguide grating preparation process according to claim 3, characterized in that: Based on the first reference grating, preparing a first grating and a third grating on a waveguide substrate comprises the following steps: Spin-coat the entire surface of the waveguide substrate with photoresist, remove the photoresist on the waveguide substrate in the area where the first reference grating is located, and obtain the waveguide substrate with the photoresist mask set; Placing the waveguide substrate provided with the photoresist mask on an exposure jig in an exposure device at a corresponding set angle, correspondingly adjusting the incident angles of the two interfering light beams in the exposure device to the first reference grating until the moiré fringe morphology appearing in the space meets the required requirements, and performing the light beam interference exposure operation of the first grating and the light beam interference exposure operation of the third grating on the photoresist mask on the waveguide substrate using the adjusted exposure device to obtain a photoresist mask with changed properties on the waveguide substrate; Performing a development operation on the photoresist mask with changed properties on the waveguide substrate to obtain a waveguide substrate with a photoresist grating mask; Using an etching baffle to shield the waveguide substrate with the photoresist grating mask, so that the waveguide substrate with the photoresist grating mask is etched only in the area where the first grating and the area where the third grating are located, and the first grating and the third grating are obtained on the waveguide substrate; Clean the remaining photoresist on the waveguide substrate.

6. The binocular waveguide grating preparation process according to claim 3, characterized in that: Based on the first out-coupling grating, preparing an in-coupling grating on a waveguide substrate comprises the following steps: Spin-coat the entire surface of the waveguide substrate with photoresist, remove the photoresist on the waveguide substrate in the area where the first reference grating is located, and obtain the waveguide substrate with the photoresist mask set; Placing the waveguide substrate provided with the photoresist mask on an exposure jig in the exposure device at a set angle; Adjusting the incident angles of the two interfering light beams in the exposure device to the first reference grating until the moiré fringe morphology appearing in the space meets the required requirements; Using the adjusted exposure equipment to perform a light beam interference exposure operation coupled into the grating on the photoresist mask on the waveguide substrate, so as to obtain a photoresist mask with changed properties on the waveguide substrate; Performing a development operation on the photoresist mask with changed properties on the waveguide substrate to obtain a waveguide substrate with a photoresist grating mask; Using an etching baffle to shield the waveguide substrate with the photoresist grating mask, so that the waveguide substrate with the photoresist grating mask is etched only in the area where the coupling grating is located and the area where the third reference grating is located, and the coupling grating and the third reference grating are obtained on the waveguide substrate, wherein the third reference grating replicates the coupling grating; Clean the remaining photoresist on the waveguide substrate.

7. The binocular waveguide grating preparation process according to claim 6, characterized in that: The second outcoupling grating adopts a second partitioned combined grating; The second subarea combined grating includes a fourth grating, a fifth grating and a sixth grating which are closely arranged; The fourth grating is a one-dimensional grating, the fifth grating is a two-dimensional grating, and the sixth grating is a one-dimensional grating; The fifth grating has the same grating lines and grating direction of the first-dimensional grating as the fourth grating, and the fifth grating has the same grating lines and grating direction of the second-dimensional grating as the sixth grating.

8. The binocular waveguide grating preparation process according to claim 7, characterized in that: Based on the coupling-in grating, preparing a second coupling-out grating on a waveguide substrate comprises the following steps: preparing a fifth grating and a fourth reference grating on a waveguide substrate, wherein the fourth reference grating replicates the fifth grating; Based on the fourth reference grating, a fourth grating and a sixth grating are prepared on a waveguide substrate.

9. The binocular waveguide grating preparation process according to claim 8, characterized in that: The step of preparing the fifth grating and the fourth reference grating on the waveguide substrate comprises the following steps: Spin-coating photoresist on the entire surface of the waveguide substrate to obtain a waveguide substrate provided with a first photoresist mask; Using the fifth reference grating to adjust the exposure device, and using the adjusted exposure device to perform a light beam interference exposure operation of the first dimension grating in the fifth grating on the first photoresist mask on the waveguide substrate, so as to obtain a first photoresist mask with changed properties on the waveguide substrate; Performing a first development operation on the first photoresist mask with changed properties on the waveguide substrate in the region where the third reference grating is located, to obtain a waveguide substrate having a photoresist grating mask in the region where the third reference grating is located; Using the photoresist grating mask of the waveguide substrate in the area where the third reference grating is located to adjust the exposure equipment, using the adjusted exposure equipment to perform a beam interference exposure operation of the second dimension grating in the fifth grating on the waveguide substrate having the photoresist grating mask in the area where the third reference grating is located, to obtain a second photoresist mask with changed properties on the waveguide substrate; Performing a development operation on the second photoresist mask with changed properties on the waveguide substrate to obtain a waveguide substrate having a second photoresist grating mask; Using an etching baffle to shield the waveguide substrate having the second photoresist grating mask, so that the waveguide substrate having the photoresist grating mask is etched only in the area where the fifth grating is located and the area where the fourth reference grating is located, and the fifth grating and the fourth reference grating are obtained on the waveguide substrate; Clean the remaining photoresist on the waveguide substrate.

10. The binocular waveguide grating preparation process according to claim 8, characterized in that: Based on the fourth reference grating, preparing a fourth grating and a sixth grating on a waveguide substrate comprises the following steps: Spin-coat the entire surface of the waveguide substrate with photoresist, remove the photoresist on the waveguide substrate in the area where the fourth reference grating is located, and obtain the waveguide substrate with the photoresist mask set; Placing the waveguide substrate provided with the photoresist mask on an exposure fixture in an exposure device at a corresponding set angle, correspondingly adjusting the incident angles of the two interfering light beams in the exposure device to the fourth reference grating until the moiré fringe morphology appearing in the space meets the required requirements, and performing the light beam interference exposure operation of the fourth grating and the light beam interference exposure operation of the sixth grating on the photoresist mask on the waveguide substrate using the adjusted exposure device to obtain a photoresist mask with changed properties on the waveguide substrate; Performing a development operation on the photoresist mask with changed properties on the waveguide substrate to obtain a waveguide substrate with a photoresist grating mask; Using an etching baffle to shield the waveguide substrate with the photoresist grating mask, so that the waveguide substrate with the photoresist grating mask is etched only in the area where the fourth grating and the area where the sixth grating are located, and the fourth grating and the sixth grating are obtained on the waveguide substrate; Clean the remaining photoresist on the waveguide substrate.

11. A binocular waveguide grating, characterized in that: The binocular waveguide grating is prepared by the preparation process of the binocular waveguide grating according to any one of claims 1 to 10.

Images