Diffractive optical waveguide and processing method therefor

Abstract

Provided in the present application are a diffractive optical waveguide and a processing method therefor. The diffractive optical waveguide comprises: a substrate; an out-coupling etched grating region, the out-coupling etched grating region being disposed on the substrate; and an imprint layer, the imprint layer and the out-coupling etched grating region being located on a same side surface of the substrate, and the out-coupling etched grating region being filled and covered by the imprint layer. An in-coupling imprint grating region is provided on the surface of the side of the imprint layer away from the substrate, and the included angle between the grating of the out-coupling etched grating region and the substrate is different from the included angle between the grating of the in-coupling imprint grating region and the substrate. The present application solves the problem of difficulty in improving the optical performance of diffractive optical waveguides in the prior art.

Description

Diffractive optical waveguide and processing method thereof

[0001] Cross-reference to Related Applications

[0002] The present application claims priority to the Chinese patent application No. 202410884291.9, filed on July 02, 2024, and entitled "Diffractive optical waveguide and processing method thereof", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the field of diffractive optics, in particular, to a diffractive optical waveguide and a processing method thereof. BACKGROUND

[0004] At present, the diffractive optical waveguide usually adopts a surface relief grating to realize light diffraction. In the processing of the diffractive optical waveguide with the surface relief grating, two ways are usually adopted to complete the processing of the key grating, such as a compression molding process and an etching process. Both of the two processes are used to complete the processing of the entire diffractive optical waveguide. The compression molding process can realize the processing of the slanted grating and the blazed grating. However, due to the limitations of the process and the material, the refractive index of the grating cannot reach more than 2.0, which limits the optical performance of the product. Although the etching process can realize the processing of the grating with a refractive index greater than 2.0, due to the process limitation, it is unable to produce large-scale batch processing of the slanted grating and the blazed grating, which also limits the optical performance of the product.

[0005] That is to say, the diffractive optical waveguide in the prior art has the problem of difficult improvement of the optical performance.

[0006] SUMMARY

[0007] The main purpose of the present application is to provide a diffractive optical waveguide and a processing method thereof to solve the problem of difficult improvement of the optical performance of the diffractive optical waveguide in the prior art.

[0008] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a diffractive optical waveguide is provided, comprising: a substrate; a coupling-out etched grating area, the coupling-out etched grating area being arranged on the substrate; a compression molding layer, the compression molding layer and the coupling-out etched grating area being located on the same side surface of the substrate, and the coupling-out etched grating area being filled and covered by the compression molding layer, the side surface of the compression molding layer away from the substrate having a coupling-in compression molding grating area, and the included angle between the grating of the coupling-out etched grating area and the substrate being different from the included angle between the grating of the coupling-in compression molding grating area and the substrate.

[0009] Optionally, the compression molding layer includes a first compression molding layer and a second compression molding layer along a direction parallel to the substrate, the first compression molding layer has the coupling-in compression molding grating area on the side surface away from the substrate, the second compression molding layer fills and covers the coupling-out etched grating area, and the thicknesses of the first compression molding layer and the second compression molding layer are the same or different.

[0010] Optionally, the projection of the in-coupling embossed grating region on the substrate is spaced apart from the projection of the out-coupling etched grating region on the substrate, the grating of the in-coupling embossed grating region is inclined to the substrate, and the grating of the out-coupling etched grating region is perpendicular to the substrate.

[0011] Optionally, the distance from the in-coupling embossed grating region to the substrate is greater than the height of the out-coupling etched grating region.

[0012] Optionally, the distance from the side surface of the second embossed layer away from the substrate to the side surface of the out-coupling etched grating region away from the substrate is greater than 0 nm and less than or equal to 1000 nm, and / or the thickness of the first embossed layer is greater than 0 nm and less than or equal to 1000 nm.

[0013] Optionally, the side surface of the embossed layer away from the substrate further has an out-coupling embossed grating region, and the out-coupling embossed grating region corresponds to the out-coupling etched grating region.

[0014] Optionally, the distance from the out-coupling embossed grating region to the substrate is equal to the distance from the in-coupling embossed grating region to the substrate, and the projection of the out-coupling embossed grating region on the out-coupling etched grating region at least partially covers the out-coupling etched grating region.

[0015] Optionally, the out-coupling etched grating region is a one-dimensional grating or a two-dimensional grating, and when the out-coupling etched grating region is a one-dimensional grating, the diffractive optical waveguide further comprises a turning etched grating region, the turning etched grating region is spaced apart from the out-coupling etched grating region on the side surface of the substrate, and the turning etched grating region is filled and covered by the embossed layer, and the grating of the turning etched grating region is perpendicular to the substrate.

[0016] Optionally, the side surface of the embossed layer away from the substrate further has a turning embossed grating region and an out-coupling embossed grating region, the turning embossed grating region corresponds to the turning etched grating region, and the out-coupling embossed grating region corresponds to the out-coupling etched grating region.

[0017] Optionally, the refractive index of the turning etched grating region and the out-coupling etched grating region is greater than or equal to 2.0 and less than or equal to 2.4, and / or the refractive index of the in-coupling embossed grating region, the turning embossed grating region and the out-coupling embossed grating region is greater than or equal to 1.5 and less than or equal to 2.0.

[0018] Optionally, the out-coupling etched grating region comprises one of TiO2 grating, SiO2 grating, ZrO2 grating, SiN grating and SiC grating, and the in-coupling embossed grating region comprises a structure of embossed glue.

[0019] According to another aspect of the present application, a processing method of a diffraction optical waveguide is provided, the diffraction optical waveguide being the diffraction optical waveguide described above, and the processing method comprising: an etching process, in which an out-coupling etching grating region is processed on one side surface of the substrate; and an imprint process, in which an imprint layer and an in-coupling imprint grating region are formed on the side surface of the substrate having the out-coupling etching grating region.

[0020] By applying the technical solution of the present application, the diffraction optical waveguide comprises a substrate, an out-coupling etching grating region, and an imprint layer, the out-coupling etching grating region being arranged on the substrate; the imprint layer and the out-coupling etching grating region are located on the same side surface of the substrate, and the out-coupling etching grating region is filled and covered by the imprint layer; the side surface of the imprint layer away from the substrate has an in-coupling imprint grating region; the included angle between the grating of the out-coupling etching grating region and the substrate is different from the included angle between the grating of the in-coupling imprint grating region and the substrate.

[0021] By arranging the out-coupling etching grating region to be filled and covered by the imprint layer, the refractive index difference is formed between the imprint layer and the out-coupling etching grating region. Since the out-coupling etching grating region is formed by the etching process, a material with a higher refractive index can be used to ensure the high diffraction efficiency of the out-coupling etching grating region, and the in-coupling imprint grating region is formed by the imprint process, different inclination angles can be achieved to make the included angle between the grating of the out-coupling etching grating region and the substrate different from the included angle between the grating of the in-coupling imprint grating region and the substrate. By matching the different materials and inclination angles of the two grating regions, higher light transmission efficiency and better color uniformity are achieved, and the performance of the diffraction optical waveguide is improved. BRIEF DESCRIPTION OF DRAWINGS

[0022] The accompanying drawings, which form a part of the present application, are intended to provide further understanding of the present application, and the illustrative embodiments of the present application and their description serve the purpose of explaining the present application. In the drawings:

[0023] FIG. 1 shows a top view of a diffraction optical waveguide according to an embodiment of the present application;

[0024] FIG. 2 shows two side views of the diffraction optical waveguide according to the embodiment of the present application;

[0025] FIG. 3 shows a top view of a diffraction optical waveguide according to another embodiment of the present application;

[0026] FIG. 4 shows two side views of the diffraction optical waveguide according to the embodiment of the present application;

[0027] FIG. 5 shows a top view of a diffraction optical waveguide according to another embodiment of the present application;

[0028] FIG. 6 shows two side views of the diffraction optical waveguide according to the embodiment of the present application;

[0029] Figure 7 shows a top view of the diffractive optical waveguide of Embodiment Four of the present application;

[0030] Figure 8 shows two side views of the diffractive optical waveguide of Embodiment Four of the present application;

[0031] Figure 9 shows a flow chart of the processing of the diffractive optical waveguide of Embodiment One of the present application.

[0032] In the above drawings, reference numerals include the following:

[0033] 10, substrate; 21, turning etched grating region; 22, out-coupling etched grating region; 31, first imprinted layer; 32, second imprinted layer; 41, in-coupling imprinted grating region; 42, turning imprinted grating region; 43, out-coupling imprinted grating region. DETAILED DESCRIPTION

[0034] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with embodiments.

[0035] It should be noted that, unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0036] In the present application, unless otherwise specified, the orientation words such as "upper", "lower", "top", "bottom" are generally directed to the directions shown in the drawings, or are directed to the vertical, perpendicular or gravity directions of the components themselves; similarly, for the convenience of understanding and description, "inner" and "outer" refer to the inner and outer relative to the contour of the components themselves, but the above orientation words are not used to limit the present application.

[0037] In order to solve the problem of difficult optical performance improvement of the existing diffractive optical waveguide, the present application provides a diffractive optical waveguide and a processing method thereof.

[0038] As shown in Figures 1 to 9, the diffractive optical waveguide comprises a substrate 10, an out-coupling etched grating region 22 and an imprinted layer, the out-coupling etched grating region 22 is arranged on the substrate 10; the imprinted layer and the out-coupling etched grating region 22 are located on the same side surface of the substrate 10, and the out-coupling etched grating region 22 is filled and covered by the imprinted layer, the side surface of the imprinted layer away from the substrate 10 has an in-coupling imprinted grating region 41, and the included angle between the grating of the out-coupling etched grating region 22 and the substrate 10 is different from the included angle between the grating of the in-coupling imprinted grating region 41 and the substrate 10.

[0039] The imprint layer is filled and covered by the coupling-out etching grating area 22, so that the refractive index difference is formed between the imprint layer and the coupling-out etching grating area 22. Since the coupling-out etching grating area 22 is formed by etching process, a material with higher refractive index can be used to ensure the high diffraction efficiency of the coupling-out etching grating area 22, and the coupling-in imprint grating area 41 is formed by imprint process, which can realize different tilt angles, so that the angle between the grating of the coupling-out etching grating area 22 and the substrate 10 is different from the angle between the grating of the coupling-in imprint grating area 41 and the substrate 10. Through the combination of different materials and tilt angles of the two grating areas, higher light transmission efficiency and better color uniformity are realized, and the performance of the diffraction optical waveguide is improved.

[0040] It should be noted that the gratings of the coupling-out etching grating area 22 and the coupling-in imprint grating area 41 are both periodic relief gratings. The coupling-out etching grating area 22 is an etching structure, that is, the coupling-out etching grating area 22 is made by etching process. The coupling-in imprint grating area 41 and the imprint layer are integrally formed, and the materials of the two are the same, which are both imprint glue structures. The coupling-out etching grating area 22 and the coupling-in imprint grating area 41 are different in material due to different manufacturing processes, and the refractive indexes are also different.

[0041] In the present application, the imprint layer includes a first imprint layer 31 and a second imprint layer 32 along the direction parallel to the substrate 10, the first imprint layer 31 has a coupling-in imprint grating area 41 away from the side surface of the substrate 10, and the second imprint layer 32 fills and covers the coupling-out etching grating area 22. The thicknesses of the first imprint layer 31 and the second imprint layer 32 are the same or different. Since the first imprint layer 31 between the coupling-in imprint grating area 41 and the substrate 10 and the second imprint layer 32 covering the coupling-out etching grating area 22 are respectively controlled in thickness, in other optional embodiments, the thickness of the first imprint layer 31 and the thickness of the second imprint layer 32 can be set to be the same. However, in the present application, the thickness of the first imprint layer 31 and the thickness of the second imprint layer 32 are different. In specific processing, the first imprint layer 31 and the second imprint layer 32 can be connected seamlessly or with a gap.

[0042] Specifically, the projection of the coupling-in imprint grating area 41 on the substrate 10 is arranged with a spacing from the projection of the coupling-out etching grating area 22 on the substrate 10, the grating of the coupling-out etching grating area 22 is arranged perpendicularly to the substrate 10, and the grating of the coupling-in imprint grating area 41 is arranged obliquely to the substrate 10, that is, the grating of the coupling-in imprint grating area 41 is not arranged perpendicularly to the substrate 10. In different embodiments of the present application, the grating of the coupling-in imprint grating area 41 includes one of a blazed grating and a slanted tooth grating. The grating of the coupling-out etching grating area 22 includes a straight tooth grating.

[0043] As shown in FIG. 2 and FIG. 4, the distance from the in-coupling imprinted grating region 41 to the substrate 10 is greater than the height of the out-coupling etched grating region 22. Specifically, the distance from the bottom of the in-coupling imprinted grating region 41 to the substrate 10 is greater than the height of the out-coupling etched grating region 22, that is, the in-coupling imprinted grating region 41 and the out-coupling etched grating region 22 are at different heights, are arranged in different layers, and have a height difference. Specifically, the distance from the in-coupling imprinted grating region 41 to the substrate 10 is equal to the thickness of the first imprinted layer 31, and the distance from the out-coupling etched grating region 22 to the substrate 10 is 0.

[0044] Specifically, the thickness of the first imprinted layer 31 is greater than 0 nm and less than or equal to 1000 nm. The distance from the side surface of the second imprinted layer 32 away from the substrate 10 to the side surface of the out-coupling etched grating region 22 away from the substrate 10 is greater than 0 nm and less than or equal to 1000 nm. That is, the second imprinted layer 32 is arranged higher than the out-coupling etched grating region 22, and the second imprinted layer 32 fills the gap of the out-coupling etched grating region 22 and completely covers the out-coupling etched grating region 22. Such an arrangement is conducive to the protection of the out-coupling etched grating region 22 by the second imprinted layer 32, while the combination of different materials of the second imprinted layer 32 and the out-coupling etched grating region 22 forms a refractive index difference, improving the diffraction performance. Preferably, the distance from the side surface of the second imprinted layer 32 away from the substrate 10 to the side surface of the out-coupling etched grating region 22 away from the substrate 10 is greater than 0 nm and less than or equal to 100 nm.

[0045] Specifically, the out-coupling etched grating region 22 is a one-dimensional grating or a two-dimensional grating. When the out-coupling etched grating region 22 is a one-dimensional grating, the diffractive optical waveguide further comprises a turning etched grating region 21, which is arranged on the side surface of the substrate 10 and spaced apart from the out-coupling etched grating region 22, and the turning etched grating region 21 is filled and covered by the second imprinted layer 32, and the grating of the turning etched grating region 21 is arranged perpendicular to the substrate 10. Specifically, the turning etched grating region 21 and the out-coupling etched grating region 22 are at the same height. When the out-coupling etched grating region 22 is a two-dimensional grating, the turning etched grating region 21 can not be arranged.

[0046] The diffractive optical waveguide of the present application will be described below in conjunction with specific embodiments and drawings.

[0047] Embodiment One

[0048] As shown in FIG. 1 and FIG. 2, the diffractive optical waveguide of embodiment one is described.

[0049] As shown in FIG. 1 and FIG. 2, the diffractive optical waveguide comprises a substrate 10, a turning etched grating region 21, a coupling-out etched grating region 22, an imprint layer and a coupling-in imprint grating region 41. The imprint layer is composed of a first imprint layer 31 and a second imprint layer 32 along the direction parallel to the substrate 10. The two side surfaces of the substrate 10 are planar, and the turning etched grating region 21 and the coupling-out etched grating region 22 are arranged on one side surface of the substrate 10 in a spaced manner, both of which are one-dimensional gratings, and the gratings of the turning etched grating region 21 and the coupling-out etched grating region 22 are straight-tooth gratings, i.e., the gratings of the turning etched grating region 21 and the coupling-out etched grating region 22 are perpendicular to the substrate 10. The second imprint layer 32 covers the side surface of the substrate 10 with the turning etched grating region 21 and the coupling-out etched grating region 22, and the projection of the imprint layer on the substrate 10 completely covers the substrate 10, and the second imprint layer 32 fills and coats the turning etched grating region 21 and the coupling-out etched grating region 22. The first imprint layer 31 is located between the coupling-in imprint grating region 41 and the substrate 10, and the projections of the coupling-in imprint grating region 41, the turning etched grating region 21 and the coupling-out etched grating region 22 on the substrate 10 are arranged in a spaced manner, specifically, the line connecting the projection of the coupling-in imprint grating region 41 on the substrate 10 to the projection of the turning etched grating region 21 on the substrate 10 is perpendicular to the line connecting the projection of the turning etched grating region 21 on the substrate 10 to the projection of the coupling-out etched grating region 22 on the substrate 10. The grating of the coupling-in imprint grating region 41 is inclined to the substrate 10.

[0050] In the embodiment, the turning etched grating region 21 and the coupling-out etched grating region 22 are both formed by etching process, and the material is transparent inorganic matter, for example, the coupling-out etched grating region 22 comprises one of TiO2 grating, SiO2 grating, ZrO2 grating, SiN grating and SiC grating, and the turning etched grating region 21 comprises one of TiO2 grating, SiO2 grating, ZrO2 grating, SiN grating and SiC grating. The refractive index of the turning etched grating region 21 and the coupling-out etched grating region 22 is greater than or equal to 2.0 and less than or equal to 2.4. The imprint layer and the coupling-in imprint grating region 41 are formed by imprint process, and the materials of the two are both transparent high-refractive-index imprint glue structure. The refractive index of the coupling-in imprint grating region 41 and the imprint layer is greater than or equal to 1.5 and less than or equal to 2.0. In the embodiment, the refractive index of the coupling-in imprint grating region 41 and the imprint layer is 1.9.

[0051] Figure 2 shows the side view of two diffraction optical waveguides of the present embodiment, the upper part shows the schematic diagram of the coupling-in embossed grating region 41 using blazed gratings, the cross section of the blazed gratings along the direction perpendicular to the substrate 10 is triangular. The lower part shows the schematic diagram of the coupling-in embossed grating region 41 using slanted gratings, the cross section of the slanted gratings along the direction perpendicular to the substrate 10 is parallelogram. The gratings of the upper and lower turning etched grating regions 21 in Figure 2 are the same, which are straight gratings, the cross section of the gratings along the direction perpendicular to the substrate 10 is rectangular. The gratings of the upper and lower coupling-out etched grating regions 22 in Figure 2 are the same, which are straight gratings, the cross section of the gratings along the direction perpendicular to the substrate 10 is rectangular.

[0052] In summary, the present embodiment realizes higher light transfer efficiency and better color uniformity in the diffraction optical waveguide by combining the coupling-in embossed grating region 41 and the turning etched grating region 21 of different materials, the coupling-in embossed grating region 41 and the coupling-out etched grating region 22 of different materials, and setting the included angle of the gratings of the above different grating regions with the substrate 10 to be different, which greatly improves the design freedom and performance of the diffraction optical waveguide.

[0053] Embodiment Two

[0054] As shown in Figures 3 and 4, the diffraction optical waveguide of embodiment two is described.

[0055] The difference between the present embodiment and embodiment one is that the coupling-out etched grating region 22 is a two-dimensional grating, and the turning etched grating region 21 is not provided. The projection of the coupling-in embossed grating region 41 on the substrate 10 is arranged apart from the projection of the coupling-out etched grating region 22 on the substrate 10.

[0056] In the present embodiment, the coupling-out etched grating region 22 is formed by etching process, and the material is transparent inorganic matter, for example, the coupling-out etched grating region 22 includes one of TiO2 grating, SiO2 grating, ZrO2 grating, SiN grating and SiC grating. The refractive index of the coupling-out etched grating region 22 is greater than or equal to 2.0 and less than or equal to 2.4. The embossed layer and the coupling-in embossed grating region 41 are formed by embossing process, and the materials of the two are both transparent high refractive index embossed glue structure. The refractive index of the coupling-in embossed grating region 41 and the embossed layer is greater than or equal to 1.5 and less than or equal to 2.0. In the present embodiment, the refractive index of the coupling-in embossed grating region 41 and the embossed layer is 1.9.

[0057] Figure 4 shows side views of two diffractive optical waveguides of the present embodiment, showing a schematic diagram of the in-coupling embossed grating region 41 using a blazed grating, which is triangular in cross-section along a direction perpendicular to the substrate 10. A schematic diagram of the in-coupling embossed grating region 41 using a slanted grating, which is parallelogram in cross-section along a direction perpendicular to the substrate 10, is shown below. The gratings of the upper and lower out-coupling etched grating regions 22 in Figure 2 are the same, which are straight gratings, rectangular in cross-section along a direction perpendicular to the substrate 10.

[0058] In summary, the present embodiment achieves higher light transfer efficiency and better color uniformity in the diffractive optical waveguide by combining the in-coupling embossed grating region 41 and the out-coupling etched grating region 22 of different materials, while the gratings of the above grating regions of different materials are arranged at different angles with respect to the substrate 10, greatly improving the design freedom and performance of the diffractive optical waveguide.

[0059] Embodiment Three

[0060] As shown in Figures 5 and 6, a diffractive optical waveguide of Embodiment Three is described.

[0061] The difference between the present embodiment and Embodiment One is that the second embossed layer 32 further has a turning embossed grating region 42 and an out-coupling embossed grating region 43 on the side surface away from the substrate 10, the turning embossed grating region 42 corresponds to the turning etched grating region 21, and the out-coupling embossed grating region 43 corresponds to the out-coupling etched grating region 22. The turning embossed grating region 42 and the out-coupling embossed grating region 43 are both inclined to the substrate 10.

[0062] In the present embodiment, the in-coupling embossed grating region 41, the turning embossed grating region 42, and the out-coupling embossed grating region 43 are all located on the side surface of the embossed layer away from the substrate 10. The distances from the in-coupling embossed grating region 41, the turning embossed grating region 42, and the out-coupling embossed grating region 43 to the substrate 10 are equal. The projection of the turning embossed grating region 42 on the turning etched grating region 21 at least partially covers the turning etched grating region 21, and the projection of the out-coupling embossed grating region 43 on the out-coupling etched grating region 22 at least partially covers the out-coupling etched grating region 22.

[0063] Specifically, the distance from the turning embossed grating region 42 to the turning etched grating region 21 along a direction perpendicular to the substrate 10 is greater than 0 nm and less than or equal to 100 nm. The distance from the out-coupling embossed grating region 43 to the out-coupling etched grating region 22 along a direction perpendicular to the substrate 10 is greater than 0 nm and less than or equal to 100 nm.

[0064] In the embodiment, the turning etched grating region 21 and the coupling-out etched grating region 22 are formed by etching process, and the material is transparent inorganic substance. The refractive index of the turning etched grating region 21 and the coupling-out etched grating region 22 is greater than or equal to 2.0 and less than or equal to 2.4. The imprint layer, the coupling-in imprint grating region 41, the turning imprint grating region 42 and the coupling-out imprint grating region 43 are formed by imprint process, and the material is transparent high refractive index imprint glue structure. The refractive index of the imprint layer, the coupling-in imprint grating region 41, the turning imprint grating region 42 and the coupling-out imprint grating region 43 is greater than or equal to 1.5 and less than or equal to 2.0. In the embodiment, the refractive index of the imprint layer, the coupling-in imprint grating region 41, the turning imprint grating region 42 and the coupling-out imprint grating region 43 is 1.9.

[0065] FIG. 6 shows the side view of two kinds of diffractive optical waveguides of the embodiment, and the upper part shows the schematic diagram when the coupling-in imprint grating region 41 adopts blazed grating, the cross section of the blazed grating in the direction perpendicular to the substrate 10 is triangular, the turning imprint grating region 42 and the coupling-out imprint grating region 43 both adopt inclined tooth grating, and the cross section of the inclined tooth grating in the direction perpendicular to the substrate 10 is parallelogram. The lower part shows the schematic diagram when the coupling-in imprint grating region 41, the turning imprint grating region 42 and the coupling-out imprint grating region 43 all adopt inclined tooth grating, and the cross section of the inclined tooth grating in the direction perpendicular to the substrate 10 is parallelogram. The gratings of the upper and lower turning etched grating regions 21 in FIG. 6 are the same, and both are straight tooth grating, and the cross section of the grating in the direction perpendicular to the substrate 10 is rectangular. The gratings of the upper and lower coupling-out etched grating regions 22 in FIG. 6 are the same, and both are straight tooth grating, and the cross section of the grating in the direction perpendicular to the substrate 10 is rectangular. The inclined directions of the gratings of the turning imprint grating region 42 and the coupling-out imprint grating region 43 in FIG. 6 are the same, and both are rightward inclined. The inclined direction of the grating of the coupling-in imprint grating region 41 is different from that of the turning imprint grating region 42, and the grating of the coupling-in imprint grating region 41 is leftward inclined.

[0066] In summary, the embodiment realizes higher light transfer efficiency and better color uniformity in the diffractive optical waveguide by combining the grating regions of different materials, and the grating of the grating region of different materials has different angles with the substrate 10, which greatly improves the design freedom and performance of the diffractive optical waveguide. Compared with the first embodiment, the design freedom of the embodiment is higher, and the performance is better.

[0067] Embodiment Four

[0068] As shown in FIG. 7 and FIG. 8, the diffractive optical waveguide of the fourth embodiment is described.

[0069] The difference between the present embodiment and embodiment two is that the second imprint layer 32 further has a coupling-out imprint grating region 43 on the side surface away from the substrate 10, and the coupling-out imprint grating region 43 corresponds to the coupling-out etching grating region 22. The grating of the coupling-out imprint grating region 43 is inclined to the substrate 10.

[0070] In the present embodiment, the coupling-in imprint grating region 41 and the coupling-out imprint grating region 43 are both located on the side surface of the imprint layer away from the substrate 10. The distance from the coupling-in imprint grating region 41 and the coupling-out imprint grating region 43 to the substrate 10 is equal. The projection of the coupling-out imprint grating region 43 on the coupling-out etching grating region 22 at least partially covers the coupling-out etching grating region 22. The distance from the coupling-out imprint grating region 43 to the coupling-out etching grating region 22 is greater than 0 nm and less than or equal to 100 nm.

[0071] In the present embodiment, the coupling-out etching grating region 22 is formed by etching process, and the material is transparent inorganic matter, for example, the coupling-out etching grating region 22 is a TiO2 grating. The refractive index of the coupling-out etching grating region 22 is greater than or equal to 2.0 and less than or equal to 2.4. The imprint layer, the coupling-in imprint grating region 41 and the coupling-out imprint grating region 43 are all formed by imprint process, and the material is transparent high-refractive-index imprint glue structure. The refractive index of the imprint layer, the coupling-in imprint grating region 41 and the coupling-out imprint grating region 43 is greater than or equal to 1.5 and less than or equal to 2.0. In the present embodiment, the refractive index of the imprint layer, the coupling-in imprint grating region 41 and the coupling-out imprint grating region 43 is 1.9.

[0072] FIG. 8 shows the side view of two kinds of diffractive optical waveguides of the present embodiment, the upper part shows the schematic diagram when the coupling-in imprint grating region 41 adopts a blazed grating, the cross section of the blazed grating in the direction perpendicular to the substrate 10 is triangular, and the coupling-out imprint grating region 43 adopts a skew grating, the cross section of the skew grating in the direction perpendicular to the substrate 10 is parallelogram. The lower part shows the schematic diagram when the coupling-in imprint grating region 41 and the coupling-out imprint grating region 43 both adopt skew gratings, the cross section of the skew grating in the direction perpendicular to the substrate 10 is parallelogram. The gratings of the upper and lower coupling-out etching grating regions 22 in FIG. 8 are the same, and both are straight-tooth gratings, the cross section of the gratings in the direction perpendicular to the substrate 10 is rectangular. The inclination direction of the grating of the coupling-out imprint grating region 43 in FIG. 8 is to the right. The inclination direction of the grating of the coupling-in imprint grating region 41 is different from that of the coupling-out imprint grating region 43, and the grating of the coupling-in imprint grating region 41 is inclined to the left.

[0073] In summary, the present embodiment realizes higher light transfer efficiency and better color uniformity in the diffractive optical waveguide by combining grating regions of different materials, and the grating of the grating region of different materials has different angles with the substrate 10, which greatly improves the design freedom and performance of the diffractive optical waveguide. Moreover, compared with embodiment two, the present embodiment has higher design freedom and better performance.

[0074] Further, the application also provides a processing method of the diffraction optical waveguide, the diffraction optical waveguide being the diffraction optical waveguide described above, the processing method comprising:

[0075] The etching process is used to process the out-coupling etching grating area 22 on one side surface of the substrate 10, or to process the out-coupling etching grating area 22 and the turning etching grating area 21.

[0076] The imprint process is used to form the imprint layer and the in-coupling imprint grating area 41 on one side surface of the substrate 10 having the out-coupling etching grating area 22, or to form the imprint layer, the in-coupling imprint grating area 41, the out-coupling imprint grating area 43, or the imprint layer, the in-coupling imprint grating area 41, the turning imprint grating area 42 and the out-coupling imprint grating area 43.

[0077] FIG. 9 describes the detailed process of the processing method of the diffraction optical waveguide, taking Example One as an example.

[0078] In the above etching process, the following steps are included:

[0079] Step S11: Obtain the substrate 10, which can be a glass wafer;

[0080] Step S12: Deposit a whole layer of inorganic transparent thin film layer with high refractive index on one side surface of the substrate 10;

[0081] Step S13: Deposit a whole layer of metal mask layer on the inorganic transparent thin film layer;

[0082] Step S14: Apply a whole layer of photoresist water or imprint glue on the metal mask layer;

[0083] Step S15: Perform the exposure process or the imprint process;

[0084] Step S16: Perform the developing process or the etching residue removal process;

[0085] Step S17: Etch the metal mask layer;

[0086] Step S18: Remove the photoresist water or the imprint glue;

[0087] Step S19: Etch the inorganic transparent thin film with high refractive index;

[0088] Step S110: Remove the metal mask layer, thereby forming the out-coupling etching grating area 22 and the turning etching grating area 21 on the substrate 10.

[0089] In the above imprint process, the following steps are included:

[0090] Step S21: coating an entire layer of high refractive index imprint glue on the side surface of the substrate 10 having the out-coupling etched grating region 22 and the turning etched grating region 21;

[0091] Step S22: aligning the sub-plate having the structure shape to the imprint glue;

[0092] Step S23: performing the imprinting process and the curing process;

[0093] Step S24: performing the sub-plate demolding process, thereby forming the imprint layer having the in-coupling imprint grating region 41.

[0094] Obviously, the above-described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work should fall within the scope of protection of the present application.

[0095] It should be noted that the terms used herein are only intended to describe specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise, and it should be further understood that the terms "comprise" and / or "include" as used in the specification indicate the presence of the features, steps, operations, devices, components and / or combinations thereof.

[0096] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0097] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A diffractive optical waveguide, characterized by, Comprising: a substrate (10); an out-coupling etched grating region (22) disposed on the substrate (10); a stamping layer, the stamping layer and the out-coupling etched grating region (22) are located on the same side surface of the substrate (10), and the out-coupling etched grating region (22) is filled and covered by the stamping layer, the stamping layer away from the side surface of the substrate (10) has an in-coupling stamping grating region (41), the angle between the grating of the out-coupling etched grating region (22) and the substrate (10) is different from the angle between the grating of the in-coupling stamping grating region (41) and the substrate (10).

2. The diffractive optical waveguide of claim 1, wherein, The stamping layer includes a first stamping layer (31) and a second stamping layer (32) along the direction parallel to the substrate (10), the first stamping layer (31) away from the side surface of the substrate (10) has the in-coupling stamping grating region (41), and the second stamping layer (32) fills and covers the out-coupling etched grating region (22), the thickness of the first stamping layer (31) and the second stamping layer (32) is the same or different.

3. The diffractive optical waveguide of claim 1, wherein, The projection of the in-coupling stamping grating region (41) on the substrate (10) is spaced apart from the projection of the out-coupling etched grating region (22) on the substrate (10), the grating of the out-coupling etched grating region (22) is disposed perpendicular to the substrate (10), and the grating of the in-coupling stamping grating region (41) is disposed oblique to the substrate (10).

4. The diffractive optical waveguide of claim 1, wherein, The distance of the in-coupling stamping grating region (41) to the substrate (10) is greater than the height of the out-coupling etched grating region (22).

5. The diffractive optical waveguide according to claim 2, wherein The distance from the side surface of the substrate (10) away from the second stamping layer (32) to the side surface of the out-coupling etched grating region (22) away from the substrate (10) is greater than 0 nm and less than or equal to 1000 nm; and / or The thickness of the first stamping layer (31) is greater than 0 nm and less than or equal to 1000 nm.

6. The diffractive optical waveguide of claim 1, wherein, The stamping layer away from the side surface of the substrate (10) also has an out-coupling stamping grating region (43), which corresponds to the out-coupling etched grating region (22).

7. The diffractive optical waveguide of claim 6, wherein, The distance of the out-coupling stamping grating region (43) to the substrate (10) is equal to the distance of the in-coupling stamping grating region (41) to the substrate (10), and the projection of the out-coupling stamping grating region (43) on the out-coupling etched grating region (22) at least partially covers the out-coupling etched grating region (22).

8. The diffractive optical waveguide of claim 1, wherein, The out-coupling etched grating region (22) is a one-dimensional grating or a two-dimensional grating, when the out-coupling etched grating region (22) is a one-dimensional grating, the diffractive optical waveguide further comprises a turning etched grating region (21), the turning etched grating region (21) is disposed on the side surface of the substrate (10) and is spaced apart from the out-coupling etched grating region (22), and the turning etched grating region (21) is filled and covered by the stamping layer, the grating of the turning etched grating region (21) is disposed perpendicular to the substrate (10).

9. The diffractive optical waveguide of claim 8, wherein, The side surface of the imprint layer away from the substrate (10) also has a turning imprint grating area (42) corresponding to the turning etching grating area (21) and a coupling-out imprint grating area (43) corresponding to the coupling-out etching grating area (22).

10. The diffractive optical waveguide according to any one of claims 1-7, wherein, The refractive index of the turning etching grating area (21) and the coupling-out etching grating area (22) is greater than or equal to 2.0 and less than or equal to 2.4; and / or The refractive index of the coupling-in imprint grating area (41), the turning imprint grating area (42) and the coupling-out imprint grating area (43) is greater than or equal to 1.5 and less than or equal to 2.

0.

11. The diffractive optical waveguide of claim 1, wherein, The coupling-out etching grating area (22) comprises one of TiO2 grating, SiO2 grating, ZrO2 grating, SiN grating and SiC grating, and the coupling-in imprint grating area (41) comprises an imprint glue structure.

12. A method of fabricating a diffractive optical waveguide, characterized by, The diffractive optical waveguide is the diffractive optical waveguide according to any one of claims 1-11, and the processing method comprises: An etching process is used to form the coupling-out etching grating area (22) on one side surface of the substrate (10); An imprint process is used to form the imprint layer and the coupling-in imprint grating area (41) on the side surface of the substrate (10) having the coupling-out etching grating area (22).

Images