Grating structure and optical waveguide device

Abstract

The invention relates to a grating structure and an optical waveguide device. The grating structure includes a first region, a second region, and a third region. The first area is a grating area. The second area is a non-grating area or another grating area. The second area is arranged outside the first area in a surrounding mode. The third area is arranged between the first area and the second area. The third area is provided with a grating transition part. Therefore, height mutation can be slowed down, and the flowability and the filling capacity of the printing glue at the boundary position are improved, so that the problems of cavities and white edges between the grating area and the non-grating area are solved, the product defect rate is reduced, and the stability and the process yield of the whole pattern are improved.

Description

Technical Field

[0001] The present application relates to the field of grating technology, and in particular to a grating structure and an optical waveguide device. Background Art

[0002] In the related art, a grating structure has a grating region and a non-grating region. There is a sudden change in height between the grating region and the non-grating region. Specifically, the height of the grating region is higher than that of the non-grating region. Grating structures are typically formed using soft template nanoimprinting. Due to the sudden change in height between the grating region and the non-grating region, the imprinting process can lead to insufficient colloid filling between the grating region and the non-grating region, which can easily produce microscopic voids and / or macroscopic white edges, seriously affecting the appearance consistency and product quality. Summary of the Invention

[0003] The embodiments of the present application provide a grating structure and an optical waveguide device, which can improve the problems of voids and white edges between the grating area and the non-grating area, reduce the product defect rate, and improve the stability of the overall pattern and the process yield.

[0004] In order to achieve the above-mentioned purpose, according to the first aspect of the present application, a grating structure is provided, including a first region, a second region and a third region, the first region is a grating region, the second region is a non-grating region or another grating region, the second region is arranged outside the first region, the third region is arranged between the first region and the second region, and the third region is provided with a grating transition portion.

[0005] Optionally, the number of the grating transition portions is at least two and they are spaced apart in the third region.

[0006] Optionally, along the same ray direction from the first region to the second region, the cross-sectional areas of at least two of the grating transition portions decrease gradually.

[0007] Optionally, along the same ray direction from the first region to the second region, the widths of at least two of the grating transition portions decrease gradually, and / or the lengths of at least two of the grating transition portions decrease gradually.

[0008] Optionally, the third region includes at least two transition regions, each of which is provided with at least two grating transition portions at intervals, and along the same ray direction from the first region to the second region, the spacing between each two adjacent grating transition portions located in different transition regions increases or decreases.

[0009] Optionally, the third region includes at least two transition regions, each of which is provided with at least two grating transition portions at intervals, and along the same ray direction from the first region to the second region, the number of the grating transition portions located in different transition regions increases.

[0010] Optionally, along the same ray direction from the first region to the second region, the total cross-sectional areas of all the grating transition portions located in different transition zones decrease.

[0011] Optionally, the grating transition portion includes a rectangular transition section and a trapezoidal transition section, and along the first direction, the rectangular transition section is spaced apart from the first region, the trapezoidal transition section is connected to the opposite ends of the rectangular transition section in the second direction, and the larger end of the trapezoidal transition section is connected to the rectangular transition section, or, the trapezoidal transition section is connected to the opposite ends of the first region in the second direction, and the larger end of the trapezoidal transition section is connected to the grating stripes of the first region, wherein the first direction is arranged at an angle to the second direction.

[0012] Optionally, the grating transition portion is configured to be parallel to the grating stripes in the first region.

[0013] According to a second aspect of the present application, an optical waveguide device is further provided, comprising the aforementioned grating structure.

[0014] In the grating structure and optical waveguide device of the embodiments of the present application, a transition connection portion is used to connect the grating area and the non-grating area, or a transition connection portion is used to connect two adjacent grating areas. This can reduce height mutations and improve the fluidity and filling capacity of the printed glue at the boundary position, thereby improving the problems of voids and white edges between the grating area and the non-grating area, reducing the product defect rate, and improving the stability of the overall pattern and the process yield.

[0015] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] To more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present application. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0017] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings, wherein the same drawing numbers represent the same parts in the following description.

[0018] Figure 1It is a structural schematic diagram of a grating structure with a cavity defect in the related art;

[0019] Figure 2 It is a structural schematic diagram of a grating structure with white edge defects in the related art;

[0020] Figure 3 is one of the structural schematic diagrams of the grating structure provided in the exemplary embodiment of the present application;

[0021] Figure 4 This is the second structural schematic diagram of the grating structure provided in the exemplary embodiment of the present application;

[0022] Figure 5 This is the third structural diagram of the grating structure provided in the exemplary embodiment of the present application;

[0023] Figure 6 is a cross-sectional view of a grating structure provided in an exemplary embodiment of the present application.

[0024] Description of reference numerals:

[0025] 1. First region; 11. Grating stripes;

[0026] 2. Second area;

[0027] 3. Third area; 31. Transition area;

[0028] 4. Grating transition section; 41. Rectangular transition section; 42. Trapezoidal transition section;

[0029] 5. Hollow;

[0030] 6. White edge. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0032] Among related technologies, diffraction waveguides offer high integration, a lightweight and thin structure, and the ability to adapt to augmented reality (AR) and virtual reality (VR) terminal devices. To meet the demand for high-precision nanostructures in optical waveguides, nanoimprint lithography is widely used to replicate the patterns of key grating structures in such devices. Compared to traditional photolithography, nanoimprint lithography offers the advantages of simple process, high resolution, low cost, and suitability for large-scale production, enabling mass production of diffraction waveguides.

[0033] Grating structures are typically fabricated using a soft-template nanoimprinting approach. Specifically, a soft template is first prepared using a high-precision hard template, which is then used to transfer the nanopattern to a photosensitive resin substrate. This approach ensures a long template life and reduces defect rates, making it particularly suitable for pattern transfer on large or uneven substrates.

[0034] However, due to the height mutation between the grating area and the non-grating area of ​​the grating structure, the imprinting colloid in the height mutation part is not fully filled during the imprinting process, e.g. Figure 1 As shown, it is easy to generate voids 5 at the microscopic level, such as Figure 2 As shown, white edges 6 are also generated at the macro level, seriously affecting the appearance consistency and product quality of the optical waveguide device.

[0035] According to the first aspect of this application, referring to Figures 3 to 6 The present application provides a grating structure. The grating structure includes a first region 1, a second region 2, and a third region 3. The first region 1 is a grating region. The second region 2 is a non-grating region or another grating region. The second region 2 is disposed around the first region 1. The third region 3 is disposed between the first region 1 and the second region 2. The third region 3 is provided with a grating transition portion 4.

[0036] In the embodiments of the present application, a transition connection portion is used to connect the grating area and the non-grating area, or a transition connection portion is used to connect two adjacent grating areas. This can slow down the height mutation and improve the fluidity and filling capacity of the printing glue at the boundary position, thereby improving the void 5 and white edge 6 problems between the grating area and the non-grating area, reducing the product defect rate, and improving the stability of the overall pattern and the process yield.

[0037] It can be understood that if the first area 1 is a grating area, the first area 1 has a number of grating stripes 11. When the second area 2 is a non-grating area, there will be a height difference between the first area 1 and the second area 2. When the second area 2 is a grating area, there may also be a height difference between the grating stripes 11 in the first area 1 and the grating stripes 11 in the second area 2. Based on the provision of a grating transition portion 4 in the third area 3 between the first area 1 and the second area 2, the grating transition portion 4 is utilized to buffer the height difference between the first area 1 and the second area 2, so that the two can transition more smoothly. Thus, the fluidity and filling capacity of the embossed colloid between the first area 1 and the second area 2 are improved by a flexible transition, effectively alleviating the problem of difficulty in filling the embossed colloid. Thus, the embossing quality between the first area 1 and the second area 2 is improved, and the possibility of defects such as voids 5 and white edges 6 is reduced.

[0038] The grating structures in the embodiments of the present application particularly include complex grating designs with variable period, line width, and orientation. These structures can be adapted for transitional connections between grating and non-grating regions, as well as between grating regions. For example, structures can include structures where the image region of the grating is recessed relative to the surrounding non-image region, or structures where the image region of the grating is raised relative to the surrounding non-image region.

[0039] The embodiments of the present application not only improve the voids 5 and white edges 6 between the grating and non-grating regions, or between two adjacent grating regions, but also achieve a transitional connection between the two adjacent grating regions. Furthermore, this transitional connection does not affect the original structure and performance of the grating regions, maintaining the high precision and efficiency of the original grating regions, significantly improving product consistency, yield, and appearance quality.

[0040] For example, the grating structure is a waveguide input coupler, an output grating, etc.

[0041] In some embodiments, the grating transition portion 4 and the grating stripes 11 in the grating region are made of the same material.

[0042] Please continue reading Figures 3 to 6 In some embodiments, there are at least two grating transition portions 4 , which are spaced apart in the third region 3 .

[0043] It is understood that the grating transition portions 4 are arranged at intervals of at least two, so that a flexible transition is formed between the first region 1 and the second region 2 through the intermittent arrangement of the at least two grating transition portions 4. This can alleviate the difficulty in embossing and filling caused by the sudden height change of the grating stripes 11 in the first region 1, improve the embossing quality, and reduce the possibility of defects such as voids 5 and white edges 6.

[0044] In some embodiments, the grating transition portion 4 has a gradient shape, so that the grating transition portion 4 can form a flexible transition between the first region 1 and the second region 2 .

[0045] In some embodiments, the grating transition portion 4 can be configured as a rectangle, a trapezoid, or a variety of other structures, such as an axis or a curve. The shape of the grating transition portion 4 can be adapted to the shape of the grating stripes 11 within the first region 1. For example, if the grating stripes 11 are configured as rectangles, the grating transition portion 4 can also be configured as a rectangle. This allows the grating transition portion 4 and the grating stripes 11 to maintain consistent pattern period and orientation.

[0046] like Figure 4 and Figure 5 As shown, in some embodiments, along the same ray direction from the first region 1 to the second region 2 , the cross-sectional areas of at least two grating transition portions 4 decrease gradually.

[0047] It can be understood that by decreasing the cross-sectional area of ​​at least two grating transition portions 4, the at least two grating transition portions 4 have the following distribution characteristics: the lines of the grating transition portions 4 are discontinuous structures, and the decreasing area causes the image density to decrease accordingly. From the first region 1 to the second region 2, all the grating transition portions 4 as a whole show a gradually decreasing area, forming a visually natural boundary attenuation, thereby effectively avoiding the underfill phenomenon caused by height mutation, and improving defects such as voids 5 and white edges 6.

[0048] Please continue reading Figure 4 and Figure 5 In some embodiments, along the same ray direction from the first region 1 to the second region 2 , the widths of at least two grating transition portions 4 decrease, and / or the lengths of at least two grating transition portions 4 decrease.

[0049] It is understood that by gradually decreasing the length and / or width of the at least two grating transition portions 4, the at least two grating transition portions 4 exhibit the following distribution characteristics: the grating transition portions 4 in the third region 3 and the grating stripes 11 in the first region 1 maintain the same grating period and orientation, while forming a pattern structure with a gradual density gradient. This creates a visually natural edge attenuation, effectively avoiding underfill caused by sudden height changes and improving defects such as voids 5 and white edges 6.

[0050] It should be noted that the width direction of the grating transition portion 4 is the first direction, and the length direction of the grating transition portion 4 is the second direction.

[0051] In some embodiments, along the same ray direction from the first region 1 to the second region 2 , the widths of at least two grating transition portions 4 decrease gradually.

[0052] In some embodiments, along the same ray direction from the first region 1 to the second region 2 , the lengths of at least two grating transition portions 4 decrease gradually.

[0053] In some embodiments, along the same ray direction from the first region 1 to the second region 2 , the widths of at least two grating transition portions 4 decrease gradually, and the lengths of at least two grating transition portions 4 decrease gradually.

[0054] In some embodiments, the width of the narrowest grating transition 4 may be less than 80 nanometers.

[0055] like Figure 6 As shown, in some embodiments, along the same ray direction from the first region 1 to the second region 2, the heights of at least two grating transition portions 4 decrease gradually. Thus, the at least two grating transition portions 4 form a buffer transition design in the height direction, thereby effectively avoiding insufficient filling caused by sudden height changes and improving defects such as voids 5 and white edges 6.

[0056] like Figure 4 As shown, in some embodiments, the third region 3 includes at least two transition regions 31, each transition region 31 is provided with at least two grating transition portions 4 at intervals, and along the same ray direction from the first region 1 to the second region 2, the spacing between each two adjacent grating transition portions 4 located in different transition regions 31 increases or decreases.

[0057] It is understood that by dividing the third region 3 into at least two transition zones 31, and spacing at least two grating transition portions 4 within each transition zone 31, the shapes of the at least two grating transition portions 4 within the same transition zone 31 can be identical. For different transition zones 31, the spacing between two adjacent grating transition portions 4 along the same ray from the first region 1 to the second region 2 can increase or decrease. This allows for a gradual density change in the grating transition portions 4. When the spacing between two adjacent grating transition portions 4 increases, the density of the grating transition portions 4 gradually decreases, resulting in a gradual decrease in the pattern area, creating a visually natural attenuation of the boundary. This effectively avoids underfilling caused by sudden height changes, thereby improving defects such as voids 5 and white edges 6. When the spacing between two adjacent grating transition portions 4 decreases, the grating transition portions 4 can form a progressively increasing pattern structure, facilitating the filling of the embossed colloid, thereby effectively avoiding underfilling caused by sudden height changes, thereby improving defects such as voids 5 and white edges 6.

[0058] In some embodiments, the number of grating transition portions 4 disposed in each transition region 31 is the same. Alternatively, the number of grating transition portions 4 disposed in each transition region 31 is different.

[0059] In some embodiments, the grating transition portions 4 disposed in each transition region 31 have the same shape.

[0060] In some embodiments, the grating transition portions 4 provided in each transition region 31 have different shapes. For example, for at least two grating transition portions 4 in the same transition region 31, the widths of the at least two grating transition portions 4 decrease along the same ray direction from the first region 1 to the second region 2. Alternatively, for at least two grating transition portions 4 in the same transition region 31, the lengths of the at least two grating transition portions 4 decrease along the same ray direction from the first region 1 to the second region 2. Alternatively, for at least two grating transition portions 4 in the same transition region 31, the heights of the at least two grating transition portions 4 decrease along the same ray direction from the first region 1 to the second region 2. Alternatively, for at least two grating transition portions 4 in the same transition region 31, the areas of the at least two grating transition portions 4 decrease along the same ray direction from the first region 1 to the second region 2.

[0061] like Figure 4As shown, in some embodiments, the third region 3 includes at least two transition regions 31, each transition region 31 is provided with at least two grating transition portions 4 at intervals, and along the same ray direction from the first region 1 to the second region 2, the number of grating transition portions 4 located in different transition regions 31 increases.

[0062] It can be understood that along the same ray direction from the first region 1 to the second region 2, the number of grating transition portions 4 located in different transition zones 31 increases gradually, so that all grating transition portions 4 can form a pattern structure with increasing density, which is beneficial to the filling of the imprinted colloid, thereby effectively avoiding the insufficient filling phenomenon caused by height mutation, and improving defects such as voids 5 and white edges 6.

[0063] like Figure 4 As shown, in some embodiments, along the same ray direction from the first region 1 to the second region 2 , the total cross-sectional areas of all grating transition portions 4 located in different transition zones 31 decrease.

[0064] It is understandable that the decreasing total cross-sectional area can make all grating transition portions 4 form a natural visual boundary attenuation, thereby effectively avoiding the insufficient filling phenomenon caused by height mutation and improving defects such as voids 5 and white edges 6.

[0065] like Figure 3 As shown, in some embodiments, the grating transition portion 4 includes a rectangular transition section 41 and a trapezoidal transition section 42. Along the first direction, the rectangular transition section 41 is spaced apart from the first region 1, and the trapezoidal transition section 42 is connected to the opposite ends of the rectangular transition section 41 in the second direction, and the larger end of the trapezoidal transition section 42 is connected to the rectangular transition section 41. Alternatively, the trapezoidal transition section 42 is connected to the opposite ends of the first region 1 in the second direction, and the larger end of the trapezoidal transition section 42 is connected to the grating stripes 11 of the first region 1, wherein the first direction is arranged at an angle to the second direction.

[0066] It is understood that the grating transition portion 4 is divided into a rectangular transition section 41 and a trapezoidal transition section 42. The rectangular transition section 41 is spaced apart from the first region 1 so that it is spaced apart from the grating stripes 11 within the first region 1 and arranged identically, so that the rectangular transition portion maintains the grating period and direction unchanged. The trapezoidal transition section 42 can give the grating transition portion 4 a characteristic of decreasing width, thereby making the grating transition portion 4 appear as a gradually decreasing image area, forming a visually natural edge attenuation, effectively avoiding underfill caused by sudden height changes, and improving defects such as voids 5 and white edges 6.

[0067] In some embodiments, the first direction and the second direction are arranged at an obtuse angle, or the first direction and the second direction are arranged at an acute angle, or the first direction and the second direction are arranged at a right angle.

[0068] The design rules of the grating transition portion 4 in the embodiment of the present application can be arbitrarily combined. Based on any combination of the design rules, the patterns formed by all transition connection portions can be made to have a linear or nonlinear decreasing trend.

[0069] For example, along the same ray direction from the first region 1 to the second region 2, the areas of the at least two grating transition portions 4 decrease gradually, and the third region 3 includes at least two transition zones 31, each transition zone 31 is provided with at least two grating transition portions 4 at intervals, and along the same ray direction from the first region 1 to the second region 2, the number of grating transition portions 4 located in different transition zones 31 increases gradually.

[0070] For example, along the same ray direction from the first region 1 to the second region 2, the widths of at least two grating transition portions 4 decrease, and the lengths of at least two grating transition portions 4 decrease. Furthermore, the third region 3 includes at least two transition zones 31, each of which is provided with at least two grating transition portions 4 at intervals. Along the same ray direction from the first region 1 to the second region 2, the spacing between each two adjacent grating transition portions 4 increases.

[0071] For example, along the same ray direction from the first region 1 to the second region 2, the widths of at least two grating transition portions 4 decrease, and the lengths of at least two grating transition portions 4 decrease. Furthermore, the third region 3 includes at least two transition zones 31, each of which is provided with at least two grating transition portions 4 at intervals. Along the same ray direction from the first region 1 to the second region 2, the spacing between two adjacent grating transition portions 4 decreases.

[0072] In some embodiments, the grating transition portion 4 is configured to be parallel to the grating stripes 11 in the first region 1. Thus, the grating transition portion 4 can maintain the grating period and direction unchanged.

[0073] According to a second aspect of the present application, an optical waveguide device is provided, the optical waveguide device including the above-mentioned grating structure. The optical waveguide device has the above-mentioned grating structure, and this application will not elaborate on it here.

[0074] In some embodiments, optical waveguide devices include VR / AR head-mounted displays (HMDs), in which grating structures can serve as diffractive optical waveguide modules. Optical waveguide devices also include high-density information display / transmission photonic chips, such as photonic crystal arrays and integrated diffraction structures. Optical waveguide devices also include optical / functional films to enhance visual consistency and image accuracy.

[0075] According to a third aspect of the present application, a grating template is provided. The grating template includes a first template area and a second template area. The first template area is used to shape the grating region. The second template area is arranged around the first template area and is used to shape the grating transition portion 4.

[0076] It can be understood that the first template area of ​​the grating template is used to form the grating area, and the second template area is used to form the grating transition part 4. Therefore, in the grating structure formed by the grating template, a grating transition part 4 can be formed between the grating area and the non-grating area (the non-grating area does not need to be formed by a template). The grating transition part 4 can slow down the sudden change between the grating area and the non-grating area, improve the fluidity and filling ability of the printing glue at the boundary position, avoid the occurrence of colloid blockage at the boundary position, thereby improving the problems of voids 5 and white edges 6 between the grating area and the non-grating area, reducing the product defect rate, and improving the stability of the overall pattern and the process yield.

[0077] In some embodiments, the grating template may be a hard template, and the hard template may be used to replicate a soft template, thereby imprinting a grating structure.

[0078] In some embodiments, the grating template may also be a soft template, and the grating structure is directly embossed using the soft template.

[0079] In some embodiments, at least two transition molding portions spaced apart are configured in the second template area.

[0080] It is understood that by constructing at least two spaced transition portions within the second template region, when the grating template forms a grating structure, at least two spaced grating transition portions 4 can be formed between the grating region and the non-grating region. The intermittent arrangement of at least two grating transition portions 4 allows for a smooth transition between the grating region and the non-grating region. This alleviates the difficulty in embossing and filling caused by the sudden height changes of the grating stripes 11 within the grating region, improves embossing quality, and reduces the likelihood of void 5 and white edge 6 defects.

[0081] In some embodiments, along the same ray direction from the first template region to the second template region, the cross-sectional areas of at least two transitional moldings decrease gradually.

[0082] It can be understood that, by gradually decreasing the cross-sectional areas of at least two transitional portions along the same ray direction from the first template area to the second template area, when the grating template forms a grating structure, the areas of at least two grating transition portions 4 can be gradually decreased. Thus, the at least two grating transition portions 4 have the following distribution characteristics: the lines of the grating transition portions 4 are discontinuous, and the decreasing area leads to a corresponding decrease in image density. From the grating area to the non-grating area, the overall area of ​​all grating transition portions 4 gradually decreases, creating a visually natural boundary attenuation. This effectively avoids underfill caused by sudden height changes and improves defects such as voids 5 and white edges 6.

[0083] In some embodiments, along the same ray direction from the first template area to the second template area, the widths of at least two transitional formed portions decrease gradually, and / or the lengths of at least two transitional formed portions decrease gradually.

[0084] It is understood that, by gradually decreasing the widths and / or lengths of at least two transitional portions along the same ray direction from the first template area to the second template area, when the grating template forms a grating structure, the lengths and / or widths of at least two grating transitional portions 4 can be gradually decreased. Consequently, the at least two grating transitional portions 4 exhibit the following distribution characteristics: the grating transitional portions 4 and the grating stripes 11 within the grating region maintain the grating period and orientation, while forming a pattern structure with a gradually changing density gradient. This creates a visually natural edge attenuation, effectively avoiding underfill caused by sudden height changes and improving defects such as voids 5 and white edges 6.

[0085] In some embodiments, along the same ray direction from the first template region to the second template region, the widths of at least two transitional forming portions decrease gradually.

[0086] In some embodiments, along the same ray direction from the first template area to the second template area, the lengths of at least two transitional forming portions decrease gradually.

[0087] In some embodiments, along the same ray direction from the first template area to the second template area, the widths of at least two transitional formed portions decrease gradually, and the lengths of at least two transitional formed portions decrease gradually.

[0088] In some embodiments, the width of the narrowest transition profile can be less than 80 nanometers.

[0089] In some embodiments, along the same ray direction from the first template area to the second template area, the height of at least two transitional moldings decreases. This allows the at least two grating transition portions 4 to form a buffered transition design in the height direction, effectively avoiding underfill caused by sudden height changes and improving defects such as voids 5 and white edges 6.

[0090] In some embodiments, the second template area includes at least two transition template areas, each transition template area is provided with at least two transition forming parts, and along the same ray direction from the first template area to the second template area, the distance between each two adjacent transition forming parts located in different transition template areas increases or decreases.

[0091] It can be understood that by increasing or decreasing the spacing between adjacent transition-molded portions located in different transition template regions along the same ray direction from the first template region to the second template region, when the grating template forms a grating structure, the spacing between adjacent grating transition portions 4 along the direction from the grating region to the non-grating region can be increased or decreased. This allows the density of the grating transition portions 4 to gradually change. When the spacing between adjacent grating transition portions 4 increases, the density of the grating transition portions 4 gradually decreases, allowing it to appear as a gradual decrease in the graphic area, forming a visually natural boundary attenuation, thereby effectively avoiding underfilling caused by sudden height changes and improving defects such as voids 5 and white edges 6. When the spacing between adjacent grating transition portions 4 decreases, the grating transition portions 4 can form an increasing pattern structure, which facilitates the filling of the imprinted colloid, thereby effectively avoiding underfilling caused by sudden height changes and improving defects such as voids 5 and white edges 6.

[0092] In some embodiments, the number of transition forming portions provided in each transition template region is the same, or the number of transition forming portions provided in each transition template region is different.

[0093] In some embodiments, the transition forming portions provided in each transition template area have the same shape.

[0094] In some embodiments, the shapes of the transition forming parts provided in each transition template area are different. For example, for at least two transition forming parts in the same transition template area, the widths of the at least two transition forming parts decrease along the same ray direction from the first template area to the second template area. Alternatively, for at least two transition forming parts in the same transition template area, the lengths of the at least two transition forming parts decrease along the same ray direction from the first template area to the second template area. Alternatively, for at least two transition forming parts in the same transition template area, the heights of the at least two transition forming parts decrease along the same ray direction from the first template area to the second template area. Alternatively, for at least two transition forming parts in the same transition template area, the areas of the at least two transition forming parts decrease along the same ray direction from the first template area to the second template area.

[0095] In some embodiments, the second template area includes at least two transition template areas, each transition template area is provided with at least two transition forming parts, and along the same ray direction from the first template area to the second template area, the number of transition forming parts located in different transition template areas increases.

[0096] It is understood that by increasing the number of transitional molded portions located in different transitional template regions along the same ray direction from the first template region to the second template region, when the grating template forms a grating structure, the number of grating transition portions 4 located in different transitional regions 31 along the direction from the grating region to the non-grating region can be increased. Thus, all grating transition portions 4 can form a pattern structure with increasing density, which facilitates filling with the imprinting colloid, effectively avoiding underfilling caused by sudden height changes, and improving defects such as voids 5 and white edges 6.

[0097] In some embodiments, along the same ray direction from the first template area to the second template area, the total cross-sectional areas of all transitional molded portions located in different transitional template areas decrease.

[0098] It is understood that by gradually decreasing the total cross-sectional area of ​​all transition-molded portions within different transition template regions, when the grating template forms a grating structure, the total cross-sectional area of ​​all grating transition portions 4 within different transition regions 31 can be gradually decreased. This gradual decrease in total cross-sectional area allows all grating transition portions 4 to form a visually natural boundary attenuation, thereby effectively avoiding underfilling caused by sudden height changes and improving defects such as voids 5 and white edges 6.

[0099] In some embodiments, the transition forming portion includes a rectangular forming section and a trapezoidal forming section. Along the first direction, the rectangular forming section is spaced apart from the first template area, the trapezoidal forming section is connected to the opposite ends of the rectangular forming section in the second direction, and the larger end of the trapezoidal forming section is connected to the rectangular forming section, or the trapezoidal forming section is connected to the opposite ends of the first template area in the second direction, and the larger end of the trapezoidal forming section is connected to the grating stripe 11 forming section of the first template area, wherein the first direction is set at an angle to the second direction.

[0100] It is understood that the rectangular shaped portion can form a rectangular transition section 41, and the trapezoidal shaped portion can form a trapezoidal transition section 42. Thus, the grating transition section 4 can be divided into a rectangular transition section 41 and a trapezoidal transition section 42. The rectangular transition section 41 is spaced apart from the grating region so that it is spaced apart from the grating stripes 11 within the grating region and arranged identically, so that the rectangular transition section maintains the grating period and direction unchanged. The trapezoidal transition section 42 can give the grating transition section 4 a characteristic of gradually decreasing width, resulting in the overall appearance of the grating transition section 4 as a gradually decreasing image area, forming a visually natural boundary attenuation, effectively avoiding underfill caused by sudden height changes, and improving defects such as voids 5 and white edges 6.

[0101] In some embodiments, the first direction and the second direction are arranged at an obtuse angle, or the first direction and the second direction are arranged at an acute angle, or the first direction and the second direction are arranged at a right angle.

[0102] In some embodiments, a grating stripe 11 forming section is provided in the first template region, and a transition forming section is parallel to the grating stripe 11 forming section. After the grating structure is formed using the grating template, the grating stripe 11 forming section corresponds to the grating stripe 11, and the transition forming section corresponds to the grating transition section 4, thereby making the grating transition section 4 parallel to the grating stripes 11 in the first region 1. This allows the grating transition section 4 to maintain a constant grating period and direction.

[0103] According to a fourth aspect of the present application, a grating imprinting method is provided, wherein the grating imprinting method uses the grating template in the above embodiment to form a grating pattern. The grating imprinting method has all the beneficial effects of the above grating template, and the present application will not elaborate on them here.

[0104] The grating imprinting method in the embodiment of the present application specifically includes:

[0105] Step 1: Use the grating template (hard template) in the above embodiment to make a soft template.

[0106] Step 2: Align and imprint the soft template with the substrate coated with the imprint colloid.

[0107] Step 3: Transfer the embossed pattern by UV curing or thermal curing to form a grating pattern with a complete boundary structure and no white edges 6.

[0108] In some embodiments, the substrate may be quartz or silicon and patterned by an electron beam lithography process.

[0109] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0110] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0111] The embodiments, implementation methods and related technical features of the present application can be combined and replaced with each other without conflict.

[0112] The above are merely preferred embodiments of the present application and do not constitute any form of limitation to the present application. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A grating structure, characterized in that: The invention comprises a first region (1), a second region (2) and a third region (3), wherein the first region (1) is a grating region, the second region (2) is a non-grating region or another grating region, the second region (2) is arranged outside the first region (1), the third region (3) is arranged between the first region (1) and the second region (2), and the third region (3) is provided with a grating transition portion (4).

2. The grating structure according to claim 1, wherein: The grating transition portions (4) are provided in at least two portions and are distributed at intervals within the third region (3).

3. The grating structure according to claim 2, wherein: Along the same ray direction from the first region (1) to the second region (2), the cross-sectional areas of at least two grating transition portions (4) decrease gradually.

4. The grating structure according to claim 2, wherein: Along the same ray direction from the first region (1) to the second region (2), the widths of at least two of the grating transition portions (4) decrease gradually, and / or the lengths of at least two of the grating transition portions (4) decrease gradually.

5. The grating structure according to claim 2, wherein: The third region (3) includes at least two transition regions (31), each of the transition regions (31) being provided with at least two grating transition portions (4) at intervals, and along the same ray direction from the first region (1) to the second region (2), the spacing between each two adjacent grating transition portions (4) located in different transition regions (31) increases or decreases.

6. The grating structure according to claim 2, wherein: The third region (3) includes at least two transition regions (31), each of the transition regions (31) being provided with at least two grating transition portions (4) at intervals, and along the same ray direction from the first region (1) to the second region (2), the number of the grating transition portions (4) located in different transition regions (31) increases.

7. The grating structure according to claim 6, wherein: Along the same ray direction from the first region (1) to the second region (2), the total cross-sectional area of ​​all the grating transition portions (4) located in different transition zones (31) decreases.

8. The grating structure according to claim 1, wherein: The grating transition portion (4) includes a rectangular transition section (41) and a trapezoidal transition section (42), wherein the rectangular transition section (41) is spaced apart from the first region (1) along a first direction, and the trapezoidal transition section (42) is connected to the two opposite ends of the rectangular transition section (41) in a second direction, and the larger end of the trapezoidal transition section (42) is connected to the rectangular transition section (41), or the trapezoidal transition section (42) is connected to the two opposite ends of the first region (1) in the second direction, and the larger end of the trapezoidal transition section (42) is connected to the grating stripes (11) of the first region (1), wherein the first direction is arranged at an angle to the second direction.

9. The grating structure according to any one of claims 1 to 8, characterized in that The grating transition portion (4) is configured to be parallel to the grating stripes (11) in the first region (1).

10. An optical waveguide device, characterized in that: Comprising the grating structure according to any one of claims 1 to 9.

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