Nanoimprint master, and optical waveguide and manufacturing method therefor

Abstract

A nanoimprint master, an optical waveguide and a manufacturing method therefor. The nanoimprint master comprises: a grating structure area; a non-grating structure area, the non-grating structure area being located around the grating structure area; and a sinking structure which is arranged on the non-grating structure area and is adjacent to the grating structure area, the sinking structure extending in the peripheral direction of the grating structure area to surround the grating structure area.

Description

Nanoimprint master and optical waveguide and method for manufacturing the same

[0001] Related applications

[0002] This application claims priority to Chinese patent application No. 202311118170.5, filed on August 31, 2023, entitled “Nanoimprint Master and Optical Waveguide and Method for Manufacturing the Same,” the entire text of which is hereby incorporated by reference. Technical Field

[0003] The present application relates to the field of nanoimprint technology, and in particular to a nanoimprint master and an optical waveguide and a method for manufacturing the same. Background Art

[0004] Nanoimprint lithography is a novel micro-nanofabrication technology that transfers micro-nano image structures onto a corresponding substrate via a template. This technology overcomes the challenges of traditional photolithography in reducing feature size, offering advantages such as nanoscale feature sizes, high resolution, and low cost. While the development and upgrading of the AR / VR industry have led to the industrialization of nanoimprint lithography for the production of optical waveguide products, the use of nanoimprint lithography for the production of optical waveguide products also presents some process challenges. For example, the edges of the grating structure area of ​​the nanoimprinted product cannot fully adhere to the substrate due to the large height difference between the grating structure area and the non-grating structure area. This results in poor edge quality and uneven adhesive residue in the grating structure area, which in turn seriously affects the optical display performance of the optical waveguide.

[0005] Summary of the Invention

[0006] According to various embodiments of the present application, a nanoimprint master and an optical waveguide and a method for manufacturing the same are provided.

[0007] In a first aspect, the present application provides a nanoimprint master, comprising:

[0008] grating structure area;

[0009] a non-grating structure region, the non-grating structure region being located around the grating structure region; and

[0010] The sinker structure is arranged on the non-grating structure region at a position adjacent to the grating structure region, and the sinker structure extends along the circumference of the grating structure region to surround the grating structure region.

[0011] In one embodiment, a distance between an inner edge of the sinker structure and an outer edge of the grating structure region is between 0.01 um and 1000 um.

[0012] In one embodiment, the processing width of the sinking structure is greater than or equal to 0.01 um.

[0013] In one embodiment, the processing depth of the sunken structure is between 0.01um and 100um.

[0014] In one embodiment, the sinker structure comprises an annular groove recessed from the surface of the non-grating structure region.

[0015] In one embodiment, the depth of the annular groove is equal to the theoretical depth of the sunken structure.

[0016] In one embodiment, the theoretical depth ΔH of the sinking structure satisfies the relationship: ΔH=H1*(1-L / P); where H1 is the grating height of the grating structure region; L is the grating line width of the grating structure region; and P is the grating period of the grating structure region.

[0017] In one embodiment, the sinking structure includes a plurality of annular grooves sunken from the surface of the non-grating structure region and interconnected, and the depths of the annular grooves decrease from the inside to the outside to form stepped grooves.

[0018] In one embodiment, the difference between the groove depths of two adjacent annular grooves is equal to the allowable depth of the sub-plate, and the allowable depth of the sub-plate is determined by the material and thickness of the sub-plate.

[0019] In one embodiment, the number N of the annular grooves satisfies the relationship: N=ROUNDUP(ΔH / Δh); wherein ROUNDUP is a rounding-up function; ΔH is a theoretical depth of the sunken structure; and Δh is an allowable depth of the sub-plate.

[0020] In a second aspect, the present application further provides an optical waveguide, comprising:

[0021] a waveguide substrate; and

[0022] A coupling grating is formed on the waveguide substrate by nanoimprinting using any of the above-mentioned nanoimprint masters.

[0023] In a third aspect, the present application further provides a method for manufacturing a nanoimprint master, comprising:

[0024] Step S100: Calculating a theoretical depth ΔH of the sunken structure based on the grating height H1, the grating line width L, and the grating period P of the grating structure region:

[0025] Step S200: obtaining the sub-plate allowable depth Δh based on the sub-plate material and sub-plate thickness;

[0026] Step S300: comparing the allowable depth Δh of the sub-plate with the theoretical depth ΔH of the sunken structure;

[0027] Step S400: If Δh ≥ ΔH, then no sinker structure is provided at a position adjacent to the grating structure region on the non-grating structure region; or, a position adjacent to the grating structure region on the non-grating structure region is etched to form a single annular groove, wherein the groove depth of the annular groove is equal to the theoretical depth of the sinker structure; and

[0028] Step S500 : If Δh<ΔH, a sinker structure is disposed on the non-grating structure region at a position adjacent to the grating structure region.

[0029] In one embodiment, step S500 includes:

[0030] Step S510: rounding down ΔH / Δh to obtain the number N of annular grooves of the sinking structure; and

[0031] Step S520 : etching a portion of the non-grating structure region adjacent to the grating structure region to form N annular grooves, where N is a positive integer.

[0032] In one embodiment, step S500 includes:

[0033] Step S510 ′: adjusting the daughter plate material and the daughter plate thickness to improve the daughter plate allowable depth to obtain the daughter plate allowable improvement depth Δh′;

[0034] Step S520′: If Δh′≥ΔH, then no sinker structure is provided at a position adjacent to the grating structure region on the non-grating structure region; alternatively, a position adjacent to the grating structure region on the non-grating structure region is etched to form a single annular groove, wherein the groove depth of the annular groove is equal to the theoretical depth of the sinker structure;

[0035] Step S530': if Δh'<ΔH, round down ΔH / Δh' to obtain the number N of annular grooves of the sinking structure; and

[0036] Step S540 ′: etching a portion of the non-grating structure region adjacent to the grating structure region to form N annular grooves, where N is a positive integer.

[0037] In one embodiment, when N=1, the depth of the annular groove is equal to the theoretical depth of the sunken structure; when N≥2, multiple annular grooves are interconnected, wherein the depths of the multiple annular grooves decrease successively from the inside to the outside, and the difference between the depths of two adjacent annular grooves is equal to the allowable depth of the sub-plate.

[0038] In a fourth aspect, the present application further provides a method for manufacturing an optical waveguide, comprising:

[0039] Manufacturing a nanoimprint master by any of the above-mentioned methods for manufacturing a nanoimprint master;

[0040] Imprinting a daughter substrate with the nanoimprint master to form a nanoimprint daughter substrate after curing; and

[0041] The waveguide substrate is imprinted by the nanoimprinting plate to form an optical waveguide after curing.

[0042] The details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the disclosed drawings without any creative work.

[0044] FIG1 is a schematic structural diagram of a nanoimprint master according to one embodiment of the present application;

[0045] FIG2 shows a first example of a nanoimprint master according to the above embodiment of the present application;

[0046] FIG3 shows a schematic diagram of a partial enlargement S of the nanoimprint master in FIG2 ;

[0047] FIG4 shows a second example of the nanoimprint master according to the above embodiment of the present application;

[0048] FIG5 is a schematic flow chart of a method for manufacturing a nanoimprint master according to one embodiment of the present application;

[0049] FIG6 shows a first example of step S500 in the method for manufacturing a nanoimprint master according to the above embodiment of the present application;

[0050] FIG. 7 shows a second example of step S500 in the method for manufacturing a nanoimprint master according to the above embodiment of the present application;

[0051] FIG8 is a schematic structural diagram of an optical waveguide according to an embodiment of the present application;

[0052] FIG9 is a schematic flow chart of a method for manufacturing an optical waveguide according to an embodiment of the present application;

[0053] FIG. 10 shows an example of a method for manufacturing an optical waveguide according to the above-described embodiment of the present application.

[0054] Explanation of the main component symbols: 10. Nanoimprint master; 11. Grating structure region; 111. In-coupling grating structure region; 112. Out-coupling grating structure region; 12. Non-grating structure region; 13. Sinking structure; 130. Annular groove; 131. In-coupling sinking structure; 132. Out-coupling sinking structure; 20. Optical waveguide; 21. Waveguide base; 211. Waveguide substrate; 212. Waveguide glue; 22. Coupling grating; 221. In-coupling grating; 222. Out-coupling grating; 30. Nanoimprint daughter plate; 300. Daughter plate base; 31. Daughter plate substrate; 32. Daughter plate glue.

[0055] The above description of the main component symbols is combined with the accompanying drawings and specific implementation methods to further illustrate this application in detail. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0057] Those skilled in the art should understand that, in the disclosure of this application, the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be understood as limiting this application.

[0058] In this application, the term "a" or "an" in the claims and the specification should be understood as "one or more." That is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple. Unless the disclosure of this application clearly indicates that the number of the element is only one, the term "a" or "an" should not be understood as unique or singular, and the term "a" or "an" should not be understood as a limitation on quantity.

[0059] In the description of this application, it should be understood that "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In the description of this application, it should be noted that, unless otherwise clearly specified and limited, "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through a medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0060] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0061] In the process of analyzing the nanoimprinting process, the applicant found that the main reasons for the poor edges and uneven residual glue defects in the grating structure area are: when the sub-plate imprints the product, there is a large height difference between the top of the grating in the grating structure area and the top of the glue layer in the non-grating structure area, and the thickness of the product glue layer is relatively thin, resulting in the sub-plate outside the grating structure area unable to be bonded to the substrate, resulting in poor edges and forming a ring-shaped defective band, which seriously affects the product appearance and optical display performance; during the imprinting and bonding process, the sub-plate at the edge of the grating structure area will be concave and deformed, resulting in the edge glue of the grating structure area cannot be fully filled, resulting in uneven residual glue defects, which will further affect the optical display performance.

[0062] In order to solve this problem, the present application creatively proposes a nanoimprint master and optical waveguide and a manufacturing method thereof, which can solve the problems of poor edges and uneven residual glue in the grating structure area in the nanoimprint process, enhance the optical display performance and improve the product appearance.

[0063] Specifically, referring to Figures 1 to 4 of the accompanying drawings of the present application, a nanoimprint master 10 is provided according to one embodiment of the present application, which may include a grating structure region 11, a non-grating structure region 12 located around the grating structure region 11, and a sinker structure 13. The sinker structure 13 is disposed on the non-grating structure region 12 adjacent to the grating structure region 11, and extends along the circumference of the grating structure region 11 to surround the grating structure region 11.

[0064] More specifically, as shown in Figures 2 and 4, the nanoimprint master 10 of the present application can have one or more grating structure regions 11. In this case, the nanoimprint master 10 also requires a corresponding number of sinker structures 13, and the sinker structures 13 surround the grating structure regions 11 one by one. For example, the nanoimprint master 10 can include an input grating structure region 111 and an output grating structure region 112 arranged at intervals. In this case, the nanoimprint master 10 needs to perform sinking processing on the peripheries of the input grating structure region 111 and the output grating structure region 112, respectively, to obtain an input sinker structure 131 surrounding the input grating structure region 111 and an output sinker structure 132 surrounding the output grating structure region 112, so as to ensure that the input grating and the output grating formed by imprint transfer do not have problems such as poor edges and uneven adhesive residue.

[0065] It is noteworthy that, since the sinking structure 13 surrounding the grating structure region 11 is provided on the non-grating structure region 12 of the nanoimprint master 10 adjacent to the grating structure region 11, the difference in height between the top of the grating transferred by the nanoimprint master 10 and the top of the glue layer in the non-grating structure region is reduced, thereby reducing or eliminating defects such as poor edges and uneven glue residue in the grating structure region caused by excessive height differences.

[0066] Optionally, as shown in FIG3 , the distance A between the inner edge of the sinker structure 13 and the outer edge of the grating structure region 11 can be between 0.01 μm and 1000 μm to protect the grating structure in the grating structure region 11 from damage. It is understood that the distance A mentioned in this application can be adjusted based on factors such as the fillability of the sub-plate material and the thickness of the sub-plate, and this application will not elaborate on this further.

[0067] Optionally, as shown in FIG3 , the processing width B of the sunken structure 13 can be greater than or equal to 0.01 μm to avoid the problem of poor ring shape caused by the processing width B of the sunken structure 13 being too small. It is understood that the processing width B mentioned in this application is related to the stiffness of the sub-plate material. That is, the stiffer the sub-plate material, the larger the processing width B required.

[0068] In addition, the processing width B of the sinker structure 13 can be less than or equal to the width of the non-grating structure area 12, that is, the sinker structure 13 can at most cover the entire non-grating structure area 12. Optionally, the processing width B of the sinker structure 13 is generally less than or equal to 30 cm.

[0069] Optionally, the processing depth of the sinking structure 13 may be between 0.01 um and 100 um to ensure that the sub-plate can be in close contact with the imprint substrate (such as the waveguide substrate).

[0070] It is worth noting that, as shown in Figure 3, the processing depth of the sunken structure 13 can be set according to the theoretical depth ΔH of the sunken structure 13, and the theoretical depth ΔH of the sunken structure 13 can be calculated according to the grating height H1, the residual glue thickness H2, and the imprint thickness H3 of the non-grating structure area of ​​the actual product, and the relationship satisfies: ΔH=H1+H2-H3; H1*L+P*H2=H3*P, where L is the grating line width of the grating structure area 11; P is the grating period of the grating structure area 11.

[0071] After sorting out, it can be seen that the theoretical depth ΔH of the sinking structure 13 satisfies the relationship ΔH=H1*(1-L / P); where H1 is the grating height of the grating structure area 11; L is the grating line width of the grating structure area 11; and P is the grating period of the grating structure area 11.

[0072] It is understood that in actual products, the sum of the grating height in the grating structure area and the thickness of the residual adhesive area is greater than the embossing thickness in the non-grating structure area. This application defines the difference between these two as the theoretical depth ΔH of the sunken structure 13. The theoretical depth ΔH of the sunken structure 13 and the allowable depth Δh of the sub-plate jointly determine whether a ring defect will occur. The allowable depth Δh of the sub-plate is determined by the sub-plate material / material and the thickness of the sub-plate. If the allowable depth Δh of the sub-plate is greater than or equal to the theoretical depth ΔH of the sunken structure 13, a ring defect will not occur even if the sunken structure is not installed. If the allowable depth Δh of the sub-plate is less than the theoretical depth ΔH of the sunken structure 13, the sunken structure must be installed to prevent the ring defect.

[0073] It is worth noting that, in order to further improve the problem of uneven residual adhesive, even if the allowable depth Δh of the daughter plate is greater than or equal to the theoretical depth ΔH of the sunken structure 13 , the nanoimprint master 10 of the present application can still be provided with the sunken structure 13 .

[0074] For example, in the first example of the present application, as shown in Figures 2 and 3, the sinking structure 13 may include a single annular groove 130 recessed from the surface of the non-grating structure area 12 to surround the grating structure area 11, so that there is a buffer between the top height of the grating after imprinting and the top height of the glue layer in the non-grating structure area, avoiding defects caused by the sub-plate not being able to contact the imprinting substrate due to excessive height difference, such as the problem of uneven residual glue at the edge of the grating structure area.

[0075] 3 , the depth of the annular groove 130 may be equal to the theoretical depth ΔH of the sunken structure 13. It is understood that in other examples of the present application, the depth of the annular groove 130 may also be greater than the theoretical depth ΔH, as long as it is not greater than the allowable depth Δh of the sub-plate.

[0076] It's worth noting that when the sub-plate allowable depth Δh is less than the theoretical depth ΔH of the sinking structure 13, if the sinking structure 13 only includes a single annular groove, the depth of this annular groove will be greater than the sub-plate allowable depth Δh, and the ring defect problem will still exist. Therefore, in the second example of the present application, as shown in Figure 4, the sinking structure 13 can include multiple annular grooves 130 that are recessed from the surface of the non-grating structure area 12 and interconnected. The groove depths of the multiple annular grooves 130 decrease from the inside to the outside to form stepped grooves, which helps to solve the ring defect caused by excessive groove depth.

[0077] Optionally, as shown in FIG4 , the depth difference between two adjacent annular grooves 130 may be equal to the sub-plate allowable depth Δh, to avoid the problem of annular defects caused by the depth difference between two adjacent annular grooves 130 being greater than the sub-plate allowable depth Δh.

[0078] Optionally, the number N of annular grooves 130 can satisfy the relationship: N = ROUNDUP(ΔH / Δh); where ROUNDUP is a round-up function, ΔH is the theoretical depth of the sunken structure, and Δh is the allowable depth of the sub-plate. Thus, the number N mentioned in this application is a positive integer greater than 1. For example, when ΔH / Δh = 1.2, N = 2; when ΔH / Δh = 2.5, N = 3, to ensure that the difference in groove depth between two adjacent annular grooves 130 is no greater than the allowable depth Δh of the sub-plate.

[0079] In summary, the sinker structure 13 mentioned in the present application can be implemented as, but is not limited to, one or more annular grooves 130 formed by etching in the non-grating structure region 12. It is understood that the annular shape mentioned in the present application is not limited to a circular ring, and can also be implemented as a rectangular ring or other types of annular structures, as long as they match the shape of the grating structure region 11. This application will not elaborate on this.

[0080] In a second aspect, as shown in FIG5 , an embodiment of the present application further provides a method for manufacturing a nanoimprint master, which may include:

[0081] Step S100: Calculating a theoretical depth ΔH of the sunken structure based on the grating height H1, the grating line width L, and the grating period P of the grating structure region:

[0082] Step S200: obtaining the sub-plate allowable depth Δh based on the sub-plate material and sub-plate thickness;

[0083] Step S300: comparing the allowable depth Δh of the sub-plate with the theoretical depth ΔH of the sunken structure;

[0084] Step S400: If Δh ≥ ΔH, then no sinker structure is provided at a position adjacent to the grating structure region on the non-grating structure region; or, a position adjacent to the grating structure region on the non-grating structure region is etched to form a single annular groove, wherein the groove depth of the annular groove is equal to the theoretical depth of the sinker structure; and

[0085] Step S500 : If Δh<ΔH, disposing a sinker structure on the non-grating structure region adjacent to the grating structure region.

[0086] It is worth noting that in step S400, when Δh≥ΔH, it is not necessary to provide a sinking structure or to provide a single annular groove, both of which can avoid the problem of annular defects.

[0087] Optionally, in the first example of the present application, as shown in FIG6 , step S500 may include:

[0088] Step S510: rounding up ΔH / Δh to obtain the number N of annular grooves of the sinking structure, where N is a positive integer greater than 1; and

[0089] Step S520: Etching the position of the non-grating structure area adjacent to the grating structure area to form N interconnected annular grooves, wherein the groove depths of the N annular grooves decrease from the inside to the outside, and the difference in groove depth between two adjacent annular grooves is equal to the allowable depth of the sub-plate.

[0090] It is worth noting that since the allowable depth Δh of the sub-plate is determined by the material and thickness of the sub-plate, the present application can improve the allowable depth of the sub-plate by adjusting the material of the sub-plate (such as the type of glue) and / or the thickness of the sub-plate to obtain an allowable improvement depth Δh' of the sub-plate that is increased compared to the allowable depth Δh of the sub-plate; at this time, if the allowable improvement depth Δh' of the sub-plate can be greater than or equal to the theoretical depth ΔH of the sinking structure, there is no need to set a sinking structure or only a single annular groove needs to be set to solve the problem of poor annularity; and if the allowable improvement depth Δh' of the sub-plate is still less than the theoretical depth ΔH of the sinking structure, multiple annular grooves must be set to form a step groove in order to solve the problem of poor annularity.

[0091] For example, in the second example of the present application, as shown in FIG7 , step S500 may include:

[0092] Step S510 ′: adjusting the daughter plate material and the daughter plate thickness to improve the daughter plate allowable depth to obtain the daughter plate allowable improvement depth Δh′;

[0093] Step S520′: If Δh′≥ΔH, then no sinker structure is provided at a position adjacent to the grating structure region on the non-grating structure region; alternatively, a position adjacent to the grating structure region on the non-grating structure region is etched to form a single annular groove, wherein the groove depth of the annular groove is equal to the theoretical depth of the sinker structure;

[0094] Step S530 ′: if Δh′<ΔH, round up ΔH / Δh′ to obtain the number N of annular grooves of the sinking structure, where N is a positive integer greater than 1; and

[0095] Step S540': etching the non-grating structure area adjacent to the grating structure area to form N interconnected annular grooves, wherein the depths of the N annular grooves decrease from the inside to the outside, and the difference in depth between two adjacent annular grooves is equal to the allowable depth of the sub-plate.

[0096] On the third aspect, as shown in FIG8 , an embodiment of the present application further provides an optical waveguide 20, which may include a waveguide substrate 21 and a coupling grating 22. The coupling grating 22 may be formed on the waveguide substrate 21 by nanoimprinting via the above-mentioned nanoimprint master 10, so as to ensure that the edge grating teeth of the coupling grating 22 have a better restoration effect, thereby reducing or eliminating the problems of poor edges and uneven residual glue.

[0097] Alternatively, as shown in FIG8 , the coupling grating 22 can be implemented as an in-coupling grating 221 and an out-coupling grating 222 spaced apart from each other on the waveguide substrate 21, wherein the in-coupling grating 221 and the out-coupling grating 222 correspond to the in-coupling grating structure region 111 and the out-coupling grating structure region 112 in the nanoimprint master 10, respectively. It is understood that the coupling grating 22 mentioned in the present application can also be implemented as a pupil expansion grating (not shown in the figure) located in the optical path between the in-coupling grating 221 and the out-coupling grating 222; accordingly, the nanoimprint master 10 is also provided with a pupil expansion grating structure region corresponding to the pupil expansion grating, which will not be described in detail in the present application.

[0098] In a fourth aspect, as shown in FIG9 , an embodiment of the present application further provides a method for manufacturing an optical waveguide, which may include the following steps:

[0099] The nanoimprint master 10 is manufactured by the above-mentioned method for manufacturing the nanoimprint master.

[0100] Imprinting the daughter plate substrate 300 with the nanoimprint master 10 to form the nanoimprint daughter plate 30 after curing; and

[0101] The waveguide substrate 21 is imprinted by the nanoimprinting plate 30 to form the optical waveguide 20 after curing.

[0102] For example, as shown in FIG10 , the daughter plate base 300 mentioned in the present application can be composed of a daughter plate substrate 31 and a daughter plate glue 32 coated on the surface of the daughter plate substrate 31 , and the nanoimprint master 10 is imprinted on the daughter plate glue 32 of the daughter plate base 300 , so that the nanoimprint daughter plate 30 can be obtained after the daughter plate glue 32 is cured.

[0103] Similarly, as shown in FIG10 , the waveguide base 21 mentioned in the present application may also be composed of a waveguide substrate 211 and a waveguide glue 212 coated on the surface of the waveguide substrate 211 before curing. The nanoimprint sub-plate 30 is imprinted on the waveguide glue 212 of the waveguide base 21, so that the optical waveguide 20 can be obtained after the waveguide glue 212 is cured.

[0104] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0105] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person skilled in the art could make numerous variations and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application.

Claims

1. A nanoimprint master, characterized in that: include: Grating structure area; a non-grating structure region, wherein the non-grating structure region is located around the grating structure region; as well as A sinker structure is disposed on the non-grating structure region and adjacent to the grating structure region, and the sinker structure extends along the peripheral direction of the grating structure region to surround the grating structure region.

2. The nanoimprint master according to claim 1, wherein: The distance between the inner edge of the sinking structure and the outer edge of the grating structure region is between 0.01 um and 1000 um.

3. The nanoimprint master according to claim 1, wherein: The processing width of the sinking structure is greater than or equal to 0.01um.

4. The nanoimprint master according to claim 1, wherein: The processing depth of the sinking structure is between 0.01um and 100um.

5. The nanoimprint master according to any one of claims 1 to 4, wherein: The sinker structure includes a single annular groove sunken from the surface of the non-grating structure area.

6. The nanoimprint master according to claim 5, wherein: The depth of the annular groove is equal to the theoretical depth of the sinking structure.

7. The nanoimprint master according to claim 6, wherein: The theoretical depth ΔH of the sinking structure satisfies the relationship: ΔH=H1*(1-L / P); wherein H1 is the grating height of the grating structure region; L is the grating line width of the grating structure region; and P is the grating period of the grating structure region.

8. The nanoimprint master according to any one of claims 1 to 4, wherein: The sinking structure includes a plurality of annular grooves which are sunken from the surface of the non-grating structure area and are interconnected. The depths of the plurality of annular grooves decrease from the inside to the outside to form stepped grooves.

9. The nanoimprint master according to claim 8, wherein: The difference between the groove depths of two adjacent annular grooves is equal to the allowable depth of the sub-plate, and the allowable depth of the sub-plate is determined by the sub-plate material and the thickness of the sub-plate.

10. The nanoimprint master according to claim 8, wherein: The number N of the annular grooves satisfies the relationship: N=ROUNDUP(ΔH / Δh); wherein ROUNDUP is a round-up function; ΔH is a theoretical depth of the sinking structure; and Δh is an allowable depth of the sub-plate.

11. An optical waveguide, characterized in that include: waveguide substrate; and The coupling grating is passed through the nanoimprint master as claimed in any one of claims 1 to 10 through the nano The waveguide substrate is formed by embossing.

12. A method for manufacturing a nanoimprint master, characterized in that: include: Step S100: Calculate the theoretical depth ΔH=H1*(1-L / P) of the sinking structure based on the grating height H1, the grating line width L and the grating period P of the grating structure region; Step S200: obtaining a sub-plate allowable depth Δh based on the sub-plate material and sub-plate thickness; Step S300: comparing the allowable depth Δh of the sub-plate with the theoretical depth ΔH of the sunken structure; Step S400: if Δh≥ΔH, then no sinking structure is provided at a position adjacent to the grating structure region on the non-grating structure region; or, a position adjacent to the grating structure region on the non-grating structure region is etched to form a single annular groove, wherein the groove depth of the annular groove is equal to the theoretical depth of the sinking structure; as well as Step S500: If Δh<ΔH, a sinker structure is disposed on the non-grating structure region at a position adjacent to the grating structure region.

13. The method for manufacturing a nanoimprint master according to claim 12, wherein: The step S500 includes: Step S510: rounding up ΔH / Δh to obtain the number N of annular grooves of the sinking structure, where N is a positive integer greater than 1; and Step S520: etching the position of the non-grating structure area adjacent to the grating structure area to form N interconnected annular grooves, wherein the depths of the N annular grooves decrease from the inside to the outside, and the difference in the depths of two adjacent annular grooves is equal to the allowable depth of the sub-plate.

14. The method for manufacturing a nanoimprint master according to claim 12, wherein: The step S500 includes: Step S510': adjusting the daughter plate material and the daughter plate thickness to improve the daughter plate allowable depth to obtain the daughter plate allowable improved depth Δh'; Step S520': if Δh'≥ΔH, then no sinking structure is provided at a position adjacent to the grating structure region on the non-grating structure region; or, a position adjacent to the grating structure region on the non-grating structure region is etched to form a single annular groove, wherein the groove depth of the annular groove is equal to the theoretical depth of the sinking structure; Step S530': if Δh'<ΔH, round up ΔH / Δh' to obtain the number N of annular grooves of the sinking structure, where N is a positive integer greater than 1; and Step S540': etching the position of the non-grating structure area adjacent to the grating structure area to form N interconnected annular grooves, wherein the depths of the N annular grooves decrease from the inside to the outside, and the difference in depth between two adjacent annular grooves is equal to the allowable depth of the sub-plate.

15. A method for manufacturing an optical waveguide, characterized in that: include: Manufacturing a nanoimprint master by the method for manufacturing a nanoimprint master as claimed in any one of claims 12 to 14; Imprinting a daughter substrate with the nanoimprint master to form a nanoimprint daughter substrate after curing; and The waveguide substrate is imprinted by the nanoimprinting plate to form an optical waveguide after curing.

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