Exposure device for manufacturing holographic volume grating waveguide

Abstract

The utility model discloses an exposure device for manufacturing a holographic volume grating waveguide. The exposure device comprises a signal light generator, a reference light generator and a first regulator. The first regulator comprises a first reflector, a first lens and a second lens which are sequentially arranged on the light path, the first reflector is provided with a rotating center located on the reflecting surface of the first reflector, the optical axes of the first lens and the second lens coincide, the first lens is provided with a first focus, and the second lens is provided with a second focus; the first focus and the second focus coincide and are located between the first lens and the second lens, the first lens and the second lens are provided with a first base point and a second base point, the first base point and the second base point are conjugated and are located on the optical axis, and the first base point is located on the side, opposite to the second lens, of the first lens and coincides with the rotation center. The second base point is located on the side, back to the first lens, of the second lens and coincides with the grating layer. The first reflecting mirror is connected with a first rotating mechanism, and the first rotating mechanism drives the first reflecting mirror to rotate around the rotating center.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical waveguides, and in particular relates to an exposure device for manufacturing holographic grating waveguides. Background Art

[0002] With the rapid development of science and technology, augmented reality (AR) technology is gradually penetrating into every corner of our lives with its unique charm, and is widely used in education, entertainment, medical treatment, industrial manufacturing and other fields. As the core carrier of this technology, the performance of the optical display system of AR devices is directly related to user experience and market acceptance. At present, AR display systems on the market generally use micro-display screens and optical combiners to realize the integration of virtual information and the real world. Among them, the optical combiner is a combination of various optical elements such as prisms, free-form surfaces, BirdBath, optical waveguides, etc. Its design is particularly critical and is also a key part to distinguish AR display systems. Among the many optical combination schemes, the optical waveguide solution is regarded as the most promising technical path due to its excellent optical effects, compact appearance and good mass production prospects.

[0003] Optical waveguides can generally be divided into two categories: geometric optical waveguides and diffraction optical waveguides. Geometric optical waveguides are so-called array optical waveguides, which achieve image output and eye box expansion by stacking array reflectors. Although this technology can provide clear image quality, its complex manufacturing process and high cost limit its wide application in the consumer market. Diffraction optical waveguides mainly include surface relief grating waveguides and holographic volume grating waveguides. Surface relief grating waveguides can be mass-produced using nanoimprinting technology, which has aroused great interest from AR optical module manufacturers. It has the advantages of large field of view and large eye movement range, but it also brings problems of light leakage and ambient light rainbow patterns. At the same time, related micro-nano processing technology is also a huge challenge. Volume holographic grating is a Bragg grating. When the wavelength and angle of the incident light meet the Bragg matching conditions, it will be diffracted with extremely high diffraction efficiency, so it has good angle selectivity and wavelength selectivity. These two characteristics can greatly suppress light leakage and ambient light rainbow patterns. In addition, volume holographic gratings also have the advantages of high diffraction efficiency, fast development iteration, large-area preparation, and low cost.

[0004] Holographic grating waveguides are manufactured based on holographic interference technology, which has advantages in color uniformity (no rainbow effect) and the realization of single-chip full-color waveguides, but are currently limited in large-scale mass production. The reason is that in the process of making holographic grating waveguides with different grating periods through dual-beam exposure technology, it is necessary to manually adjust the angle and position of exposure, resulting in poor efficiency in both precision control and optical path adjustment. Therefore, it is necessary to propose an exposure scheme to improve the efficiency of exposing holographic grating waveguides. Utility Model Content

[0005] The present invention aims to overcome at least one defect in the prior art and provide an exposure device for manufacturing a holographic grating waveguide, so as to solve the problem of low exposure efficiency caused by low optical path adjustment efficiency.

[0006] In order to solve the above technical problems, the following technical solutions are adopted:

[0007] The holographic grating waveguide generally includes a waveguide layer and a grating layer stacked in layers, and the exposure device proposed in this scheme includes a signal light generator for emitting signal light and a reference light generator for emitting reference light. In particular, the exposure device also includes a first regulator for adjusting the incident angle of the signal light or the reference light.

[0008] The first adjuster includes a first reflector, a first lens, and a second lens which are sequentially arranged on an optical path, the first reflector has a rotation center located on its reflection surface, the optical axis of the first lens coincides with the optical axis of the second lens, the first lens has a first focus, the second lens has a second focus, the first focus and the second focus coincide and are located between the first lens and the second lens, the first lens and the second lens have a first base point and a second base point, the first base point and the second base point are conjugate and are both located on the optical axis, the first base point is located on the side of the first lens facing away from the second lens and coincides with the rotation center, the second base point is located on the side of the second lens facing away from the first lens and coincides with the grating layer; the first reflector is connected to a first rotating mechanism, the first rotating mechanism drives the first reflector to rotate around the rotation center to adjust the incident angle of the signal light or the reference light on the grating layer.

[0009] In this solution, the incident angle and the exit angle of the signal light or the reference light on the first reflector are adjusted by the rotation of the first reflector, and the synergistic effect of the first lens and the second lens is used to ensure that the incident angle of the signal light or the reference light on the grating layer changes accordingly while the irradiation area remains basically unchanged, so that the first reflector only needs to rotate a certain angle without moving its position to change the incident angle of the signal light or the reference light on the grating layer, and at the same time, it can ensure that the adjusted signal light or the reference light can always be incident on the grating layer and interfere, and even the center of the irradiated area of ​​the grating layer always coincides with the second focus of the second lens, thereby greatly improving the efficiency of manufacturing the holographic grating waveguide.

[0010] The first rotating mechanism can be an electric rotating table or an electric angle table. An electric rotating table is an electric mechanical device that can rotate around a fixed axis, usually composed of one or more motors, reducers, bearings, turntables and control systems, etc., which can realize continuous or intermittent rotation of objects, and has the characteristics of high precision, high speed, large torque and good stability. An electric angle table (sometimes also called an electric tilt table or angle adjustment table) is a device that can accurately rotate an object within a small angle range, usually including a rotatable platform, a motor, a reducer, an angle sensor and a control system, etc., which can realize precise angle adjustment of the object, and has the characteristics of high precision, high resolution and fast response. By electrically controlling the rotation of the first reflector through an electric rotating table or an electric angle table, not only can manual adjustment be avoided, further improving the efficiency of manufacturing holographic grating waveguides, but also the exposure angle can be accurately controlled, greatly improving the manufacturing accuracy of holographic grating waveguides.

[0011] The exposure device can be configured with two groups of first adjusters, one group is used to adjust the incident angle of the signal light on the grating layer, and the other group is used to adjust the incident angle of the reference light on the grating layer. The second base points of the two groups of first adjusters coincide, ensuring that the irradiation area of ​​the signal light on the grating layer and the irradiation area of ​​the reference light on the grating layer overlap as much as possible.

[0012] The exposure device may also be configured with a set of first regulators and a set of second regulators. If the first regulator is used to adjust the incident angle of the signal light on the grating layer, the second regulator is used to adjust the incident angle of the reference light on the grating layer. If the first regulator is used to adjust the incident angle of the reference light on the grating layer, the second regulator is used to adjust the incident angle of the signal light on the grating layer.

[0013] The second adjuster includes a second reflector, and the second reflector is connected to a rotation and movement mechanism. If the second adjuster is used to adjust the incident angle of the reference light on the grating layer, the second reflector is arranged on the reference light path, and the rotation and movement mechanism drives the second reflector to rotate to adjust the incident angle of the reference light on the grating layer, and drives the second reflector to move so that the illumination area of ​​the reference light on the grating layer overlaps with the illumination area of ​​the signal light on the grating layer. If the second adjuster is used to adjust the incident angle of the signal light on the grating layer, the second reflector is arranged on the signal light path, and the rotation and movement mechanism drives the second reflector to rotate to adjust the incident angle of the signal light on the grating layer, and drives the second reflector to move so that the illumination area of ​​the signal light on the grating layer overlaps with the illumination area of ​​the reference light on the grating layer.

[0014] The rotating and moving mechanism can be an electric multi-dimensional combination table integrating the functions of rotation and movement, or a combination of a second rotating mechanism driving the second reflector to rotate and a first moving mechanism driving the second reflector to move. The second rotating mechanism can be an electric rotating table or an electric angular table, and the first moving mechanism can be an electric translation table or an electric lifting table. The electric multi-dimensional combination table is a precision device that integrates electric drive technology and multi-dimensional motion capabilities. It is mainly used to achieve precise displacement and positioning of multiple axes (such as X, Y, Z axes and possible rotation axes). It has the characteristics of high precision, multi-axis linkage, and good stability. The electric translation table is a mechanical device that achieves linear displacement through electric drive. It is usually composed of a motor, a reducer, a transmission mechanism, a guide rail, and a platform. It can accurately move the load in a specified direction and has the characteristics of high precision, high stability, and large load-bearing capacity. The electric lifting table is an electric mechanical device that can achieve lifting in the vertical direction. It is usually composed of a motor, a reducer, a lifting mechanism, a support structure, and a control system. It can carry objects of a certain weight and achieve smooth lifting and lowering movements. It has the characteristics of large load-bearing capacity, high stability, and easy operation. By electrically controlling the rotation and movement of the second reflector through an electric rotating table, an electric angle table, an electric translation table, an electric lifting table, an electric multi-dimensional combination table, etc., not only can manual adjustment be avoided, but also the exposure angle and exposure position can be precisely controlled, thereby improving the production efficiency and production accuracy of the holographic grating waveguide.

[0015] The exposure device can also be equipped with a stage for loading the holographic grating waveguide, which plays a role in positioning and fixing the holographic grating waveguide. The stage can be connected to the second moving mechanism, which can drive the stage to move, thereby driving the holographic grating waveguide loaded on the stage to move, until the grating layer in the holographic grating waveguide coincides with the second focus of the second lens, ensuring that the second focus of the second lens is exactly located on the grating layer.

[0016] The second moving mechanism can be an electric translation stage or an electric lifting stage. By electrically controlling the movement of the stage through the electric translation stage or the electric lifting stage, manual adjustment can be avoided and the position of the holographic grating waveguide loaded on the stage can be precisely controlled, further improving the production efficiency and production accuracy of the holographic grating waveguide.

[0017] The signal light generator can be configured with a signal light source and a first lens group. The signal light source generates a first light beam and emits it to the first lens group. The first lens group shapes the first light beam and emits the signal light. The first lens group can shape the first light beam into a parallel light beam or a divergent light beam. In other words, the signal light emitted by the signal light generator can be a parallel light beam or a divergent light beam.

[0018] The reference light generator can be configured with a reference light source and a second lens group. The reference light source generates a second light beam and emits it to the second lens group. The second lens group shapes the second light beam and emits the reference light. The second lens group can shape the second light beam into a parallel light beam or a divergent light beam. In other words, the reference light emitted by the reference light generator can be a parallel light beam or a divergent light beam.

[0019] Compared with the prior art, this solution has the following beneficial effects: this solution ensures that the incident angle of the signal light or the reference light on the grating layer changes with the rotation of the first reflector through the synergistic effect of the first lens and the second lens, while the irradiated area remains basically unchanged, so that the first reflector only needs to rotate a certain angle without moving its position to change the incident angle of the signal light or the reference light on the grating layer, and at the same time ensures that the adjusted signal light or the reference light can always be incident on the grating layer and interfere, and even the center of the irradiated area of ​​the grating layer always coincides with the second focus of the second lens, greatly improving the efficiency of manufacturing holographic grating waveguides. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings are for illustrative purposes only and should not be construed as limitations on the present invention. In order to better illustrate the present invention, some parts of the drawings may be omitted, enlarged, or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0021] Figure 1 It is a schematic diagram of the structure of a holographic grating waveguide.

[0022] Figure 2 This is the exposure optical path diagram of the holographic grating waveguide.

[0023] Figure 3 Is Figure 2 The reconstructed optical path diagram of the holographic grating waveguide made by the exposure optical path shown.

[0024] Figure 4 is a schematic diagram of the grating period.

[0025] Figure 5 This is an exposure optical path diagram of a holographic grating waveguide that uses a reflector to change the incident angles of signal light and reference light.

[0026] Figure 6 It is a schematic diagram of the structure of an exposure device equipped with two groups of first regulators.

[0027] Figure 7 It is a schematic diagram of the structure of an exposure device in which a first regulator is configured in a signal light path.

[0028] Figure 8It is a structural schematic diagram of an exposure device in which a first regulator is configured in a reference light path.

[0029] Fig. 9 It is a relationship table between the grating period and the exposure angle of the first regulator.

[0030] Fig.10 It is a relationship table between the grating period and the exposure angle and exposure position of the second regulator.

[0031] Explanation of reference numerals: waveguide layer 001 , grating layer 002 , signal light generator 100 , reference light generator 200 , first reflecting mirror 311 , first rotating mechanism 312 , first lens 321 , second lens 322 , second reflecting mirror 411 , rotating movement mechanism 412 , stage 510 , second movement mechanism 520 . DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the present solution, the present solution is further described in detail below in conjunction with specific embodiments.

[0033] Figure 1 The structure of the holographic grating waveguide is shown in FIG. The holographic grating waveguide includes a waveguide layer 001 and a grating layer 002, both of which are layered structures and are stacked. The waveguide layer 001 has two opposite surfaces, namely a first surface and a second surface. The grating layer 002 can be arranged on the surface or inside of the waveguide layer 001, specifically, it can be arranged on the first surface of the waveguide layer 001, it can also be arranged on the second surface of the waveguide layer 001, and it can also be arranged between the first surface and the second surface of the waveguide layer 001 to form a stacked structure with the waveguide layer 001.

[0034] The waveguide layer 001 is generally made of a material with a high refractive index. It acts as a high refractive index medium, and the air around it acts as a low refractive index medium. The two surfaces of the waveguide layer 001 act as the interface between the high refractive index medium and the low refractive index medium. When light is incident from the high refractive index medium to the interface with the low refractive index medium, the absolute value of the incident angle is greater than the critical angle of total reflection θ. c The light will be completely reflected back, and then propagate forward along the extension direction of the medium in the form of back and forth reflection in the high refractive index medium. This propagation can be called total reflection propagation. In addition, the two surfaces of the waveguide layer 001 are attached with only the incident angle greater than the critical angle of high reflection θ. r The light has a high reflectivity material, and can also make most of the incident angles greater than the high reflection critical angle θ rThe light is reflected back and can also propagate forward along the extension direction of the medium in the form of back and forth reflection in the waveguide layer 001. This propagation can be called high reflection propagation. Whether it is total reflection propagation or high reflection propagation, the waveguide layer 001 can realize back and forth reflection propagation of light.

[0035] The grating layer 002 can be an in-coupling grating, an out-coupling grating, a turning grating, or a combination of any two or more of the in-coupling grating, the out-coupling grating, the turning grating, etc. The in-coupling grating is used to couple the projection beam into the waveguide layer 001, so that the projection beam can be reflected back and forth in the waveguide layer 001. The out-coupling grating is used to expand the range of the projection beam and couple the projection beam out of the waveguide layer 001, so that the projection beam that is reflected back and forth in the waveguide layer 001 can be emitted outside the waveguide layer 001 to enter the human eye. The turning grating is used to change the propagation direction of the projection beam in the waveguide layer 001 and expand the beam range.

[0036] The grating layer 002 is generally formed by a holographic photosensitive material under double-beam interference exposure. Figures 2-3 The most common exposure optical path and corresponding reproduction optical path of the holographic grating waveguide are illustrated respectively. The signal light generator 100 generates signal light, and the reference light generator 200 generates reference light. The two are irradiated onto the grating layer 002 to be exposed to form double-beam interference. The holographic photosensitive material records the interference fringe distribution in the form of a refractive index change distribution. The fringe corresponds to the grating structure to form the final holographic grating waveguide. The reproduction process is the use process. When the light is incident on the grating layer 002 along the direction of the reference light, diffraction occurs, generating direct light L0 (0th order light) and diffracted light L +1 (+1 level light), the direction of the direct light is consistent with the direction of the reference light, and the direction of the diffracted light is consistent with the direction of the signal light. Therefore, after the signal light is recorded on the holographic photosensitive material using the reference light to form the grating layer 002, the signal light can be reproduced by the light with the direction consistent with the reference light.

[0037] The grating period d of the diffraction grating can be decomposed into the surface period ∧s and the vertical period ∧z, as Figure 4. In actual design, the surface period ∧s of the grating is generally designed to be a fixed value first, and then the vertical period ∧z of the grating is adjusted to obtain a holographic volume grating with different Bragg matching angles or wavelengths, thereby optimizing the performance of the volume holographic grating waveguide. From the grating formula: nλ=d(sinα-sinβ), it can be seen that when the wavelength λ and the diffraction order are constant, the incident angle α and the diffraction angle β need to be adjusted to produce a holographic volume grating waveguide with different grating periods d. The incident angle α and the diffraction angle β correspond to the angle of the reference light emitted by the reference light generator 200 and the angle of the signal light emitted by the signal light generator 100 in the exposure process. These two angles need to be artificially changed to produce a holographic volume grating waveguide with different grating periods d. To this end, a reflector can be set between the signal light generator 100 and the holographic volume grating waveguide and between the reference light generator 200 and the holographic volume grating waveguide, such as Figure 5 , the incident angles of the signal light and the reference light on the grating layer 002 are adjusted by rotating the reflector. However, rotating the reflector will not only change the incident angles of the signal light and the reference light, but also change the irradiation areas of the signal light and the reference light, resulting in that the signal light and the reference light that meet the target incident angle may not necessarily interfere with each other on the grating layer 002, or may not even be incident on the grating layer 002. In addition, manual adjustment not only has poor precision control, but also the efficiency of manually modifying the exposure angle is not high.

[0038] Figures 6 to 8 The exposure device for making a holographic volume grating waveguide is illustrated. The exposure device includes not only a signal light generator 100 for emitting a signal light and a reference light generator 200 for emitting a reference light, but also a first adjuster for adjusting the incident angle of the signal light or the reference light.

[0039] The first adjuster includes a first reflector 311, a first lens 321, and a second lens 322. The first reflector 311, the first lens 321, and the second lens 322 are sequentially arranged on an optical path, which may be a signal light path or a reference light path. If the first reflector 311, the first lens 321, and the second lens 322 are arranged on the signal light path, the signal light emitted by the signal light generator 100 will be reflected by the first reflector 311, and then enter the first lens 321 and the second lens 322 in sequence, and finally be incident on the grating layer 002. If the first reflector 311, the first lens 321, and the second lens 322 are arranged on the reference light path, the reference light emitted by the reference light generator 200 will be reflected by the first reflector 311, and then enter the first lens 321 and the second lens 322 in sequence, and finally be incident on the grating layer 002.

[0040] The first reflector 311 is connected to a first rotating mechanism 312 and has a rotation center O, which is located on the reflection surface of the first reflector 311. The first rotating mechanism 312 drives the first reflector 311 to rotate around the rotation center O. The optical axis of the first lens 321 coincides with the optical axis of the second lens 322. The first lens 321 has a first focus F1, and the second lens 322 has a second focus F2. The first focus F1 and the second focus F2 coincide and are located between the first lens 321 and the second lens 322. The first lens 321 and the second lens 322 have a pair of conjugate points, which are the first base point A1 and the second base point A2. The first base point A1 and the second base point A2 are both located on the optical axes of the first lens 321 and the second lens 322. The first base point A1 is located on the side of the first lens 321 facing away from the second lens 322, and coincides with the rotation center O. The second base point A2 is located on the side of the second lens 322 facing away from the first lens 321, and coincides with the grating layer 002. Therefore, as long as the first reflector 311 is rotated around the rotation center O by a certain angle, the incident angle of the signal light or the reference light on the grating layer 002 can be changed without adjusting the position of the first reflector 311, and at the same time, it can be ensured that the adjusted signal light or the reference light can always be incident on the grating layer 002 and interfere, and even the center of the illuminated area of ​​the grating layer 002 always coincides with the second focus of the second lens 322, which greatly improves the efficiency of making the holographic grating waveguide. Through a large number of experiments, a relationship table between the grating period and the exposure angle (the angle of the first reflector 311) can be obtained, as shown in FIG. Fig. 9 (All values ​​in the figure are virtual values, which need to be obtained according to specific exposure device experiments during the equipment debugging phase). During production, it is only necessary to rotate the first reflector 311 according to the target grating period and the relationship table.

[0041] The first rotating mechanism 312 can adopt an electric rotating mechanism such as an electric rotating table and an electric angle table, so as to electrically control the rotation of the first reflector 311, which can not only avoid manual adjustment and further improve the efficiency of making the holographic grating waveguide, but also enable the exposure angle to be accurately controlled, greatly improving the manufacturing accuracy of the holographic grating waveguide. The electric rotating table is an electric mechanical device that can rotate around a fixed axis, usually composed of one or more motors, reducers, bearings, turntables and control systems, etc., which can realize continuous or intermittent rotation of an object, and has the characteristics of high precision, high speed, high torque and good stability. The electric angle table (sometimes also called an electric tilt table or angle adjustment table) is a device that can accurately rotate an object within a small angle range, usually including a rotatable platform, a motor, a reducer, an angle sensor and a control system, etc., which can realize accurate angle adjustment of the object, and has the characteristics of high precision, high resolution and fast response.

[0042] The exposure device can be equipped with two sets of first regulators, such as Figure 6 , one group is arranged on the signal light path, used to adjust the incident angle of the signal light on the grating layer 002, and the other group is arranged on the reference light path, used to adjust the incident angle of the reference light on the grating layer 002, and the second base points A2 of the two groups of first adjusters coincide with each other, ensuring that the irradiation area of ​​the signal light on the grating layer 002 and the irradiation area of ​​the reference light on the grating layer 002 overlap as much as possible. The exposure device can also be configured with only one group of first adjusters, which are either arranged on the reference light path, such as Figure 7 , used to adjust the incident angle of the reference light on the grating layer 002, or set in the signal light path, such as Figure 8 , used to adjust the incident angle of the signal light on the grating layer 002.

[0043] In the case where the exposure device is only equipped with one set of first adjusters, the exposure device can also adjust the incident angle of the light on another optical path through the second adjuster. Specifically, if the incident angle of the signal light is adjusted by the first adjuster, the second adjuster is arranged on the reference light path, and is used to adjust the incident angle of the reference light on the grating layer 002. If the incident angle of the reference light is adjusted by the first adjuster, the second adjuster is arranged on the signal light path, and is used to adjust the incident angle of the signal light on the grating layer 002.

[0044] The second regulator includes a second reflector 411, which is arranged on the optical path and is connected to a rotation and movement mechanism 412. The rotation and movement mechanism 412 drives the second reflector 411 to rotate to adjust the incident angle of the reference light or the signal light on the grating layer 002, and drives the second reflector 411 to move so that the reference light and the signal light overlap in the irradiation area of ​​the grating layer 002, thereby achieving the purpose of controlling the exposure angle (the angle of the second reflector 411) and the exposure position (the position of the second reflector 411). Through a large number of experiments, a relationship table between the grating period and the exposure angle and exposure position can be obtained, such as Fig.10 (All the values ​​in the figure are virtual values, which need to be obtained according to the specific exposure device experiment during the equipment debugging stage). When making, it is only necessary to rotate and move the first reflector 311 according to the target grating period and the relationship table.

[0045] The rotating and moving mechanism 412 can adopt an electric displacement mechanism such as an electric multi-dimensional combination table that integrates the functions of rotation and movement, or a combination of electric rotating mechanisms such as an electric rotating table, an electric angle table, and electric moving mechanisms such as an electric translation table and an electric lifting table, so as to electrically control the rotation and movement of the second reflector 411, which can not only avoid manual adjustment, but also enable the exposure angle and exposure position to be accurately controlled, thereby improving the production efficiency and production accuracy of the holographic grating waveguide. The electric multi-dimensional combination table is a precision device that integrates electric drive technology and multi-dimensional motion capabilities, and is mainly used to achieve precise displacement and positioning of multiple axes (such as X, Y, Z axes and possible rotation axes), and has the characteristics of high precision, multi-axis linkage, good stability, etc. The electric translation table is a mechanical device that realizes linear displacement through electric drive, usually composed of a motor, a reducer, a transmission mechanism, a guide rail, a platform, etc., and can accurately move the load in a specified direction, and has the characteristics of high precision, high stability and large load-bearing capacity. An electric lift is an electric mechanical device that can achieve vertical lifting and lowering. It is usually composed of a motor, a reducer, a lifting mechanism, a support structure and a control system. It can carry objects of a certain weight and achieve smooth lifting and lowering movements. It has the characteristics of large carrying capacity, high stability and easy operation.

[0046] In contrast, the second adjuster not only needs to adjust the angle of the second reflector 411, but also needs to adjust the position of the second reflector 411 in order to adjust the incident angle of the signal light or the reference light and ensure that the irradiation area before and after the adjustment remains basically unchanged; while the first adjuster only needs to adjust the angle of the first reflector 311 to adjust the incident angle of the signal light or the reference light and ensure that the irradiation area before and after the adjustment remains basically unchanged, so the adjustment efficiency is higher, and the efficiency of manufacturing the holographic grating waveguide is correspondingly higher.

[0047] The exposure device can also be equipped with a stage 510. The stage 510 is used to load the holographic grating waveguide, and plays a role in positioning and fixing the holographic grating waveguide. Different holographic grating waveguides may have different thicknesses, and the position of the grating layer 002 in the holographic grating waveguide may also be different. In order to ensure that the second focus of the second lens 322 is exactly located on the grating layer 002, the stage 510 can be connected to the second moving mechanism 520, and the second moving mechanism 520 can drive the stage 510 to move, thereby driving the holographic grating waveguide loaded on the stage 510 to move, until the grating layer 002 in the holographic grating waveguide coincides with the second focus of the second lens 322.

[0048] The second moving mechanism 520 can adopt an electric moving mechanism such as an electric translation table, an electric lifting table, etc., so as to electrically control the movement of the stage 510, which can not only avoid manual adjustment, but also enable the position of the holographic grating waveguide loaded on the stage 510 to be precisely controlled, thereby further improving the production efficiency and production accuracy of the holographic grating waveguide.

[0049] The signal light generator 100 may be configured with a signal light source and a first lens 321 group. The signal light source generates a first light beam and emits it to the first lens 321 group. The first lens 321 group shapes the first light beam and emits the signal light. The first lens 321 group may shape the first light beam into a parallel light beam or into a divergent light beam. In other words, the signal light emitted by the signal light generator 100 may be a parallel light beam or a divergent light beam.

[0050] The reference light generator 200 may be configured with a reference light source and a second lens group 322. The reference light source generates a second light beam and emits it to the second lens group 322. The second lens group 322 shapes the second light beam and emits the reference light. The second lens group 322 may shape the second light beam into a parallel light beam or into a divergent light beam. In other words, the reference light emitted by the reference light generator 200 may be a parallel light beam or a divergent light beam.

[0051] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. An exposure device for making a holographic grating waveguide, wherein the holographic grating waveguide comprises a waveguide layer and a grating layer stacked, and the exposure device comprises a signal light generator for emitting a signal light and a reference light generator for emitting a reference light; characterized in that: The exposure device also includes a first regulator for adjusting the incident angle of the signal light or the reference light; the first regulator includes a first reflector, a first lens, and a second lens sequentially arranged on the optical path, the first reflector has a rotation center located on its reflection surface, the optical axis of the first lens coincides with the optical axis of the second lens, the first lens has a first focus, the second lens has a second focus, the first focus and the second focus coincide and are located between the first lens and the second lens, the first lens and the second lens have a first base point and a second base point, the first base point and the second base point are conjugate and are both located on the optical axis, the first base point is located on the side of the first lens facing away from the second lens and coincides with the rotation center, the second base point is located on the side of the second lens facing away from the first lens and coincides with the grating layer; the first reflector is connected to a first rotating mechanism, the first rotating mechanism drives the first reflector to rotate around the rotation center to adjust the incident angle of the signal light or the reference light on the grating layer.

2. The exposure device for making a holographic grating waveguide according to claim 1, characterized in that: The exposure device includes two groups of first adjusters, one group is used to adjust the incident angle of the signal light on the grating layer, and the other group is used to adjust the incident angle of the reference light on the grating layer. The second base points of the two groups of first adjusters coincide.

3. The exposure device for making a holographic grating waveguide according to claim 1 or 2, characterized in that: The first rotating mechanism is an electric rotating table or an electric angular table.

4. The exposure device for making a holographic grating waveguide according to claim 1, characterized in that: The first regulator is used to adjust the incident angle of the signal light on the grating layer, and the exposure device also includes a second regulator for adjusting the incident angle of the reference light; the second regulator includes a second reflector arranged on the optical path, and the second reflector is connected to a rotating movement mechanism, and the rotating movement mechanism drives the second reflector to rotate to adjust the incident angle of the reference light on the grating layer, and drives the second reflector to move so that the irradiation area of ​​the reference light on the grating layer overlaps with the irradiation area of ​​the signal light on the grating layer.

5. The exposure device for making a holographic grating waveguide according to claim 1, characterized in that: The first regulator is used to adjust the incident angle of the reference light on the grating layer, and the exposure device also includes a second regulator for adjusting the incident angle of the signal light; the second regulator includes a second reflector arranged on the optical path, and the second reflector is connected to a rotating movement mechanism, and the rotating movement mechanism drives the second reflector to rotate to adjust the incident angle of the signal light on the grating layer, and drives the second reflector to move so that the irradiation area of ​​the signal light on the grating layer overlaps with the irradiation area of ​​the reference light on the grating layer.

6. The exposure device for making a holographic grating waveguide according to claim 4 or 5, characterized in that: The rotating movement mechanism is an electric multi-dimensional combination table; or The rotation and movement mechanism includes a second rotation mechanism for driving the second reflector to rotate and a first movement mechanism for driving the second reflector to move. The second rotation mechanism is an electric rotation table or an electric angle table, and / or the first movement mechanism is an electric translation table or an electric lifting table.

7. The exposure device for making a holographic grating waveguide according to claim 1, 2, 4 or 5, characterized in that: The exposure device also includes a stage for loading the holographic grating waveguide.

8. The exposure device for manufacturing a holographic grating waveguide according to claim 7, characterized in that: The stage is connected to a second moving mechanism, and the second moving mechanism drives the stage to move to ensure that the grating layer coincides with the second focus of the second lens.

9. The exposure device for manufacturing a holographic grating waveguide according to claim 8, characterized in that: The second moving mechanism is an electric translation platform or an electric lifting platform.

10. The exposure device for making a holographic grating waveguide according to claim 1, 2, 4 or 5, characterized in that: The signal light generator comprises a signal light source and a first lens group, the signal light source generates a first light beam and emits it to the first lens group, the first lens group shapes the first light beam and emits the signal light; and / or The reference light generator includes a reference light source and a second lens group. The reference light source generates a second light beam and emits the second light beam to the second lens group. The second lens group shapes the second light beam and emits the reference light.

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