Volume holographic optical waveguide structure
By setting a fixed layer on the substrate and using two or three beams of light to interfere with the exposure of the photosensitive layer, the problems of light propagation and image effect caused by excessive beams in the prior art are solved, thereby improving the quality of the grating and enhancing its convenience.
Patent Information
- Application Number
- CN202520037508.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-06
- Publication Date
- 2025-12-30
- Estimated Expiration
- 2035-01-06
AI Technical Summary
In the prior art, optical waveguide sheets obtained by coating materials on a rigid substrate or filling a liquid crystal cell are prone to excessive beams during exposure, resulting in problems with unexposed areas and affecting light propagation and image quality.
A photosensitive layer is placed on the upper surface of a substrate using a fixed layer. One-dimensional or two-dimensional expanded pupil waveguides are obtained by interference exposure using two or three beams. The photosensitive layer is cut into the required shape and placed according to the position of the grating, which simplifies the optical path device, reduces whitening around the grating, and improves the grating quality.
It effectively reduces beam overlap problems, improves grating quality, and enhances the convenience of optical waveguide sheets and the light propagation effect.
Smart Images
Figure CN223742779U_ABST
Abstract
Description
Technical Field
[0001] The embodiments of this application belong to the field of optical technology, and in particular relate to a volume holographic waveguide structure. Background Technology
[0002] Currently, holographic gratings have one-dimensional and two-dimensional optical waveguides. There are two methods to obtain the optical waveguide sheet: one is to coat a material on a rigid substrate and then cover it with a film, and the other is to fill a liquid crystal cell with a photosensitive material to obtain the waveguide sheet. Then, the two types of optical waveguides are subjected to corresponding interference exposure by limiting their shapes through apertures. The above two methods result in excessive exposure beams, and various problems are prone to occur in the non-exposed areas, affecting light propagation and image quality. Summary of the Invention
[0003] To solve or alleviate the above problems, embodiments of this application provide a volume holographic optical waveguide structure, including: a first substrate, a first photosensitive layer, and a second photosensitive layer;
[0004] A first photosensitive layer and a second photosensitive layer are disposed on the upper surface of the first substrate at intervals through a fixing layer; the fixing layer has the same refractive index as the first substrate, the first photosensitive layer and the second photosensitive layer.
[0005] The fixed layer has the same refractive index as the first photosensitive layer, the second photosensitive layer and the first substrate. A one-dimensional pupil-expanding waveguide sheet can be obtained by exposing the first photosensitive layer and the second photosensitive layer through the interference of two beams.
[0006] As a preferred embodiment of this application, a second substrate is also included;
[0007] The second substrate is disposed on the upper surface of the first substrate;
[0008] The first photosensitive layer and the second photosensitive layer are respectively disposed between the first substrate and the second substrate through the fixing layer.
[0009] As a preferred embodiment of this application, a third photosensitive layer is also included;
[0010] The third photosensitive layer is spaced apart from the first and second photosensitive layers;
[0011] A two-dimensional pupil-expanding waveguide sheet can be obtained by exposing the first, second, and third photosensitive layers through three-beam interference.
[0012] As a preferred embodiment of this application, a third photosensitive layer is also included;
[0013] The third photosensitive layer is disposed between the first substrate and the second substrate via the fixing layer; the third photosensitive layer is disposed at an interval from the first photosensitive layer and the second photosensitive layer.
[0014] A two-dimensional pupil-expanding waveguide sheet can be obtained by exposing the first, second, and third photosensitive layers through three-beam interference.
[0015] In a preferred embodiment of this application, both the first substrate and the second substrate are composed of glass, resin, or silicon.
[0016] In a preferred embodiment of this application, the fixing layer is an optical adhesive.
[0017] Compared with the prior art, the embodiments of this application cut the photosensitive layer into the required shape and attach it to the substrate surface. Different gratings are placed in different positions according to different design schemes. Different types of gratings can be obtained through a simple optical path device. There is no photosensitive material in the non-grating area, so it can be illuminated. The exposed light source can be irradiated, which can reduce the whitening around the grating and the problem of beam overlap, improve the grating quality, and greatly improve convenience. Attached Figure Description
[0018] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. Some specific embodiments of this application will be described in detail below with reference to the accompanying drawings in an exemplary and non-limiting manner. The same reference numerals in the drawings designate the same or similar parts or components. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:
[0019] Figure 1 A schematic diagram of the volume holographic waveguide structure provided in Embodiment 1 is shown;
[0020] Figure 2 A schematic diagram of the volume holographic waveguide structure provided in Embodiment 2 is shown;
[0021] Figure 3 A schematic diagram of the volume holographic waveguide structure provided in Embodiment 3 is shown;
[0022] Figure 4 A schematic diagram of the volume holographic waveguide structure provided in Embodiment 4 is shown. Detailed Implementation
[0023] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort should fall within the scope of protection of the present application.
[0024] Example 1
[0025] This application provides a volume holographic optical waveguide structure, including: a first substrate 1, a first photosensitive layer 2, and a second photosensitive layer 3;
[0026] A first photosensitive layer 2 and a second photosensitive layer 3 are disposed at intervals on the upper surface of the first substrate 1 through a fixing layer (not shown);
[0027] The fixed layer (not shown) has the same refractive index as the first photosensitive layer 2, the second photosensitive layer 3 and the first substrate 1. A one-dimensional pupil-expanding waveguide sheet can be obtained by exposing the first photosensitive layer 2 and the second photosensitive layer 3 through the interference of two beams.
[0028] Specifically, the substrate material can be glass, resin, silicon wafer, etc. According to the design requirements, the first photosensitive layer 2 and the second photosensitive layer 3 can be set at intervals, and the first photosensitive layer 2 and the second photosensitive layer 3 can be of arbitrary shape. The first photosensitive layer 2 and the second photosensitive layer 3 are set at corresponding positions on the substrate through a fixing layer, and only two beams are needed to obtain a one-dimensional optical waveguide at once.
[0029] In this embodiment, the fixing layer (not shown) is an optical adhesive, and the fixing layer has the same refractive index as the first substrate 1, the first photosensitive layer 2, and the second photosensitive layer 3.
[0030] It should be noted that the first photosensitive layer 2 and the second photosensitive layer 3 need to be located at the position of the optical path.
[0031] Example 2
[0032] Based on Embodiment 1, the volume holographic waveguide structure further includes a second substrate 4;
[0033] The second substrate 4 is disposed on the upper surface of the first substrate 1;
[0034] The first photosensitive layer 2 and the second photosensitive layer 3 are respectively disposed between the first substrate 2 and the second substrate 3 through the fixing layer.
[0035] In this embodiment, the first photosensitive layer 2 and the second photosensitive layer 3 are fixed between the first substrate 1 and the second substrate 2. By exposing the first photosensitive layer 2 and the second photosensitive layer 3 through the interference of two beams, a one-dimensional pupil-expanding waveguide sheet can be obtained in one step.
[0036] Example 3
[0037] Based on Embodiment 1, the volume holographic waveguide structure further includes a third photosensitive layer 5;
[0038] The third photosensitive layer 5 is disposed at an interval from the first photosensitive layer 2 and the second photosensitive layer 3;
[0039] A two-dimensional pupil-expanding waveguide sheet can be obtained by exposing the first photosensitive layer 2, the second photosensitive layer 3, and the third photosensitive layer 5 through three-beam interference.
[0040] Example 4
[0041] Based on Embodiment 2, the volume holographic waveguide structure also includes a third photosensitive layer 5;
[0042] The third photosensitive layer 5 is disposed between the first substrate 1 and the second substrate 2 via the fixing layer; the third photosensitive layer 5 is disposed at an interval from the first photosensitive layer 2 and the second photosensitive layer 3.
[0043] A two-dimensional pupil-expanding waveguide sheet can be obtained by exposing the first photosensitive layer 2, the second photosensitive layer 3, and the third photosensitive layer 5 through three-beam interference.
[0044] The above embodiments of this application cut the photosensitive layer into the required shape and attach it to the substrate surface. Different grating positions are placed according to different design schemes. Different types of gratings can be obtained through a simple optical path device. There is no photosensitive material in the non-grating area, so it can be illuminated. The exposed light source can be used for illumination, which can reduce the whitening around the grating and the problem of beam overlap, improve the grating quality, and greatly improve convenience.
[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A volume holographic optical waveguide structure, characterized by Comprise: A first substrate, a first photosensitive layer and a second photosensitive layer; The first substrate upper surface is provided with the first photosensitive layer and the second photosensitive layer through a fixed layer, the fixed layer has the same optical refractive index as the first substrate, the first photosensitive layer and the second photosensitive layer; The fixed layer has the same refractive index as the first photosensitive layer, the second photosensitive layer and the first substrate, and one-dimensional pupil expanding optical waveguide sheet can be obtained by exposing the first photosensitive layer and the second photosensitive layer through two beams of light.
2. A volume holographic optical waveguide structure as claimed in claim 1, characterized in that Also comprising a second substrate; The second substrate is arranged on the upper surface of the first substrate; The first photosensitive layer and the second photosensitive layer are arranged between the first substrate and the second substrate through the fixed layer.
3. A volume holographic optical waveguide structure as claimed in claim 1, characterized in that Also comprising a third photosensitive layer; The third photosensitive layer is arranged between the first photosensitive layer and the second photosensitive layer through the fixed layer; Two-dimensional pupil expanding optical waveguide sheet can be obtained by exposing the first photosensitive layer, the second photosensitive layer and the third photosensitive layer through three beams of light.
4. A volume holographic optical waveguide structure as claimed in claim 2, characterized in that Also comprising a third photosensitive layer; The third photosensitive layer is arranged between the first substrate and the second substrate through the fixed layer; the third photosensitive layer is arranged between the first photosensitive layer and the second photosensitive layer through the fixed layer; Two-dimensional pupil expanding optical waveguide sheet can be obtained by exposing the first photosensitive layer, the second photosensitive layer and the third photosensitive layer through three beams of light.
5. A volume holographic optical waveguide structure as claimed in claim 2, wherein, The first substrate and the second substrate are composed of one of glass, resin and silicon.
6. A volume holographic optical waveguide structure as claimed in claim 2, wherein, The fixed layer is optical glue.