Grating structure and optical waveguide device

Abstract

The application relates to a grating structure and an optical waveguide device. The grating structure comprises 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 annularly arranged outside the first region. The third region is arranged between the first region and the second region. The third region is provided with a grating transition part. Thus, the height mutation can be slowed down, the flowability and filling capacity of the printing glue at the boundary position are improved, the cavity and white edge problems between the grating region and the non-grating region are improved, the product defect rate is reduced, and the stability of the overall pattern and the process yield are improved.

Description

Technical Field

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

[0002] In related technologies, grating structures have grating regions and non-grating regions. There is a height abrupt change between the grating and non-grating regions. Specifically, the height of the grating region is greater than that of the non-grating region. Grating structures are typically formed using soft template nanoimprinting. Due to this height abrupt change between the grating and non-grating regions, insufficient colloid filling can occur during the imprinting process, easily resulting in microscopic voids and / or macroscopic white edges, severely affecting appearance consistency and product quality. Summary of the Invention

[0003] This application provides 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] To achieve the above objectives, according to a first aspect of this application, a grating structure is provided, comprising a first region, a second region, and a third region, wherein the first region is a grating region, the second region is a non-grating region or another grating region, the second region is disposed around the first region, and the third region is disposed between the first region and the second region, and the third region is provided with a grating transition portion.

[0005] Optionally, the grating transition portions are configured as at least two and are distributed at intervals within the third region.

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

[0007] Optionally, along the same ray direction from the first region to the second region, the width of at least two of the grating transition portions decreases, and / or the length of at least two of the grating transition portions decreases.

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

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

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

[0011] Optionally, the grating transition portion includes a rectangular transition segment and a trapezoidal transition segment. Along the first direction, the rectangular transition segment is spaced apart from the first region, and the trapezoidal transition segment is connected to the opposite ends of the rectangular transition segment in the second direction, with the larger end of the trapezoidal transition segment connected to the rectangular transition segment. Alternatively, the trapezoidal transition segment is connected to the opposite ends of the first region in the second direction, with the larger end of the trapezoidal transition segment connected to the grating stripes of the first region, wherein the first direction and the second direction are set at an angle.

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

[0013] According to a second aspect of this application, an optical waveguide device is also provided, including the grating structure as described above.

[0014] In the grating structure and optical waveguide device of this application embodiment, the transition connection is used to connect the grating area and the non-grating area, or to connect two adjacent grating areas. This can slow down height abrupt changes, improve the fluidity and filling ability of the printing paste at the boundary position, thereby improving the 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 this application will be described in detail in the following detailed description section. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0018] Figure 1This is a schematic diagram of a grating structure with void defects in related technologies;

[0019] Figure 2 This is a schematic diagram of a grating structure with white edge defects in related technologies;

[0020] Figure 3 This is one of the structural schematic diagrams of the grating structure provided in the exemplary embodiments of this application;

[0021] Figure 4 This is a second schematic diagram of the grating structure provided in the exemplary embodiments of this application;

[0022] Figure 5 This is the third schematic diagram of the grating structure provided in the exemplary embodiments of this application;

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

[0024] Explanation of reference numerals in the attached figures:

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

[0026] 2. Second area;

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

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

[0029] 5. Hollow;

[0030] 6. White border. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0032] Among related technologies, diffractive waveguides possess high integration, a thin and lightweight 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 waveguides, nanoimprint lithography is widely used for pattern replication of key grating structures in these devices. Compared to traditional photolithography, nanoimprint lithography offers advantages such as simpler process, higher resolution, lower cost, and suitability for large-area production, enabling mass production of diffractive waveguides.

[0033] A soft-stencil nanoimprinting method is typically used to fabricate grating structures. Specifically, a soft stencil is first prepared using a high-precision hard stencil, and then the nanopattern is transferred onto a photosensitive resin substrate using the soft stencil. This method allows the stencil to have a longer lifespan and can reduce the defect rate, making it particularly suitable for pattern transfer on large-sized or uneven substrates.

[0034] However, due to the abrupt changes in height between the grating and non-grating regions of the grating structure, the imprinting colloid in the abruptly changed areas is not fully filled during the imprinting process, such as... Figure 1 As shown, voids can easily form at the microscopic level, such as... Figure 2 As shown, it will also produce white edges at the macroscopic level, which seriously affects the appearance consistency and product quality of optical waveguide devices.

[0035] According to the first aspect of this application, referring to Figures 3 to 6 This 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 has a grating transition portion 4.

[0036] In the embodiments of this application, the transition connection is used to connect the grating area and the non-grating area, or to connect two adjacent grating areas. This can slow down height abrupt changes, improve the flowability and filling ability of the printing adhesive at the boundary position, thereby improving the 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.

[0037] It is understandable that if the first region 1 is a grating region, then the first region 1 has several grating stripes 11. When the second region 2 is a non-grating region, there will be a height difference between the first region 1 and the second region 2. When the second region 2 is a grating region, there may also be a height difference between the grating stripes 11 in the first region 1 and the grating stripes 11 in the second region 2. By providing a grating transition portion 4 in the third region 3 between the first region 1 and the second region 2, the height difference between the first region 1 and the second region 2 can be buffered, allowing for a smoother transition. Thus, by using a flexible transition method, the flowability and filling ability of the imprinting adhesive between the first region 1 and the second region 2 are improved, effectively alleviating the problem of difficult filling of the imprinting adhesive. As a result, the imprinting quality between the first region 1 and the second region 2 is improved, and the possibility of void defects 5 and white edge defects 6 is reduced.

[0038] The grating structures in the embodiments of this application particularly include complex grating designs with variable period, linewidth, and orientation. Furthermore, they can be applied to transitions between grating regions and non-grating regions, as well as between grating regions themselves. For example, structures where the image region of the grating is recessed relative to the surrounding non-image region, and structures where the image region of the grating protrudes relative to the surrounding non-image region.

[0039] The embodiments of this application can not only improve the voids 5 and white edges 6 defects between grating areas and non-grating areas, or improve the voids 5 and white edges 6 defects between two adjacent grating areas, but also achieve a transition connection between two adjacent grating areas. At the same time, this transition connection method will not affect the original structure and performance of the grating area, maintain the high precision and high efficiency of the original grating area, and significantly improve the consistency, yield and appearance quality of the product.

[0040] For example, grating structures include waveguide input couplers and output gratings.

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

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

[0043] Understandably, the grating transition portions 4 are spaced at least two apart, so that the first region 1 and the second region 2 form a flexible transition through the at least two intermittently arranged grating transition portions 4. This can alleviate the problem of imprinting filling difficulties caused by abrupt changes in the height of the grating stripes 11 within the first region 1, improve imprinting quality, and reduce the possibility of voids 5 and white edges 6 defects.

[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, trapezoid, or various 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 rectangular, then the grating transition portion 4 is also rectangular. This ensures that the grating transition portion 4 and the grating stripes 11 maintain consistency in pattern period and direction.

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

[0047] It is understandable that the cross-sectional area of ​​at least two grating transition sections 4 is reduced, thereby the at least two grating transition sections 4 have the following distribution characteristics: the lines of the grating transition sections 4 are discontinuous structures, and the decreasing area reduces the image density accordingly. From the first region 1 to the second region 2, all grating transition sections 4 show a gradual reduction in area, forming a visually natural boundary attenuation, thereby effectively avoiding the phenomenon of insufficient filling caused by height abrupt changes, and improving defects such as holes 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 width of at least two grating transition portions 4 decreases, and / or the length of at least two grating transition portions 4 decreases.

[0049] It is understood that by decreasing the length and / or width of at least two grating transition portions 4, the at least two grating transition portions 4 have the following distribution characteristics: the grating transition portion 4 in the third region 3 and the grating stripes 11 in the first region 1 can maintain the grating period and direction unchanged, and form a pattern structure with a gradually changing density gradient. This creates a visually natural boundary attenuation, effectively avoiding insufficient filling caused by abrupt height changes, and improving defects such as holes 5 and white edges 6.

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

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

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

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

[0055] like Figure 6 As shown, in some embodiments, the height of at least two grating transition portions 4 decreases along the same ray direction from the first region 1 to the second region 2. This creates a buffer transition design in the height direction for the at least two grating transition portions 4, effectively avoiding insufficient filling caused by abrupt 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, and at least two grating transition portions 4 are provided in each transition region 31 at intervals. Along the same ray direction from the first region 1 to the second region 2, the spacing between each pair of adjacent grating transition portions 4 in different transition regions 31 increases or decreases.

[0057] It is understood that by dividing the third region 3 into at least two transition regions 31, and by providing at least two grating transition portions 4 at intervals within each transition region 31, the shapes of the at least two grating transition portions 4 within the same transition region 31 can be identical. For different transition regions 31, the spacing between two adjacent grating transition portions 4 increases or decreases along the same ray direction from the first region 1 to the second region 2. This allows for a gradual change in the density of 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, so that the pattern area gradually decreases, forming a visually natural boundary attenuation, thereby effectively avoiding insufficient filling caused by abrupt height changes and 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 an increasing pattern structure, which is beneficial for filling the imprinted adhesive, thereby effectively avoiding insufficient filling caused by abrupt height changes and improving defects such as voids 5 and white edges 6.

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

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

[0060] In some embodiments, the shapes of the grating transition portions 4 disposed in each transition region 31 are different. For example, for at least two grating transition portions 4 in the same transition region 31, the width of the at least two grating transition portions 4 decreases 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 length of the at least two grating transition portions 4 decreases 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 height of the at least two grating transition portions 4 decreases 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 area of ​​the at least two grating transition portions 4 decreases 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, and at least two grating transition portions 4 are provided in each transition region 31 at intervals. 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 is understandable that the number of grating transition portions 4 located in different transition zones 31 increases along the same ray direction from the first region 1 to the second region 2, which can enable all grating transition portions 4 to form a pattern structure with increasing density, which is beneficial for filling the imprinted colloid, thereby effectively avoiding the phenomenon of insufficient filling caused by height abrupt change, 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 area of ​​all grating transition portions 4 located in different transition regions 31 decreases.

[0064] Understandably, the decrease in total cross-sectional area can create a visually natural boundary decay in all grating transition sections 4, thereby effectively avoiding the phenomenon of insufficient filling caused by abrupt changes in height, 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, with the larger end of the trapezoidal transition section 42 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, with the larger end of the trapezoidal transition section 42 connected to the grating stripe 11 of the first region 1. The first direction and the second direction are set at an angle.

[0066] Understandably, the grating transition section 4 is divided into a rectangular transition segment 41 and a trapezoidal transition segment 42. The rectangular transition segment 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 in the same manner, so that the grating period and direction of the rectangular transition section remain unchanged. The trapezoidal transition segment 42 gives the grating transition section 4 a characteristic of decreasing width, so that the overall image area of ​​the grating transition section 4 gradually decreases, forming a visually natural boundary attenuation, thereby effectively avoiding the phenomenon of insufficient filling caused by abrupt changes in height, and improving defects such as holes 5 and white edges 6.

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

[0068] The design rules for the grating transition section 4 in this embodiment can be arbitrarily combined. Based on the arbitrary combination of design rules, the patterns formed by all transition connections can exhibit a linear or non-linear decreasing trend.

[0069] For example, along the same ray direction from the first region 1 to the second region 2, the area of ​​at least two grating transition portions 4 decreases, and the third region 3 includes at least two transition regions 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 number of grating transition portions 4 located in different transition regions 31 increases.

[0070] For example, along the same ray direction from the first region 1 to the second region 2, the width of at least two grating transition portions 4 decreases, and the length of at least two grating transition portions 4 decreases. Furthermore, the third region 3 includes at least two transition regions 31, each transition region 31 having at least two grating transition portions 4 spaced apart, and along the same ray direction from the first region 1 to the second region 2, the spacing between every 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 width of at least two grating transition portions 4 decreases, and the length of at least two grating transition portions 4 decreases. Furthermore, the third region 3 includes at least two transition regions 31, each transition region 31 having at least two grating transition portions 4 spaced apart, and along the same ray direction from the first region 1 to the second region 2, the spacing between every 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 within the first region 1. This allows the grating transition portion 4 to maintain a constant grating period and orientation.

[0073] According to a second aspect of this application, an optical waveguide device is provided, which includes the grating structure described above. The optical waveguide device has the aforementioned grating structure, which will not be elaborated further herein.

[0074] In some embodiments, the optical waveguide device includes a VR / AR head-mounted display device, where a grating structure can serve as a diffractive optical waveguide module. The optical waveguide device also includes high-density information display / transmission photonic chips, such as photonic crystal arrays, integrated diffractive structures, etc. The optical waveguide device further includes optical films / functional films to improve visual consistency and graphic accuracy.

[0075] According to a third aspect of this 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 form a grating region. The second template area is disposed around the first template area. The second template area is used to form a grating transition portion 4.

[0076] It is understandable 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. Thus, in the grating structure formed by the grating template, the 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 the template). The grating transition part 4 can slow down the abrupt change in degree between the grating area and the non-grating area, improve the fluidity and filling ability of the printing adhesive at the boundary position, avoid the phenomenon of adhesive blockage at the boundary position, thereby improving the voids 5 and white edges 6 between the grating area and the non-grating area, reducing the product defect rate, and improving the overall pattern stability and process yield.

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

[0078] In some embodiments, the grating template can also be a soft template, in which case the grating structure can be directly formed by pressing the soft template.

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

[0080] It is understandable that by constructing at least two spaced transition molding portions within the second template area, when the grating template forms the grating structure, at least two spaced grating transition portions 4 can be formed between the grating area and the non-grating area. This allows for a flexible transition between the grating area and the non-grating area through the intermittently arranged at least two grating transition portions 4. Consequently, the problem of imprinting filling difficulties caused by abrupt changes in the height of the grating stripes 11 within the grating area can be alleviated, imprinting quality can be improved, and the possibility of voids 5 and white edges 6 defects can be reduced.

[0081] In some embodiments, along the same ray direction from the first template area to the second template area, the cross-sectional area of ​​at least two transition forming portions decreases.

[0082] It is understandable that by making the cross-sectional area of ​​at least two transition parts decrease along the same ray direction from the first template area to the second template area, when the grating template forms a grating structure, the area of ​​at least two grating transition parts 4 can be reduced. Therefore, the at least two grating transition parts 4 have the following distribution characteristics: the lines of the grating transition parts 4 are discontinuous, the decreasing area reduces the image density, and from the grating area to the non-grating area, all grating transition parts 4 exhibit a gradual decrease in area, forming a visually natural boundary attenuation, thereby effectively avoiding insufficient filling caused by height abrupt changes, and improving defects such as holes 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 width of at least two transition forming portions decreases, and / or the length of at least two transition forming portions decreases.

[0084] It is understandable that by making the width of at least two transition molding portions decrease and / or the length of at least two transition molding portions decrease along the same ray direction from the first template area to the second template area, when the grating template forms a grating structure, the length and / or width of at least two grating transition portions 4 can be reduced. Thus, the at least two grating transition portions 4 have the following distribution characteristics: the grating transition portions 4 and the grating stripes 11 within the grating area can maintain the grating period and direction unchanged, and form a pattern structure with a gradually changing density gradient. This creates a visually natural boundary attenuation, effectively avoiding insufficient filling caused by abrupt 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 area to the second template area, the width of at least two transition forming portions decreases.

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

[0087] In some embodiments, along the same ray direction from the first template area to the second template area, the width of at least two transition forming portions decreases, and the length of at least two transition forming portions decreases.

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

[0089] In some embodiments, the height of at least two transition molding portions decreases along the same ray direction from the first template area to the second template area. This allows at least two grating transition portions 4 to form a buffered transition design in the height direction, effectively avoiding insufficient filling caused by abrupt 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, and at least two transition forming parts are provided at intervals in each transition template area. Along the same ray direction from the first template area to the second template area, the spacing between each pair of adjacent transition forming parts in different transition template areas increases or decreases.

[0091] It is understandable that by increasing or decreasing the spacing between any two adjacent transition molding portions located in different transition template areas along the same ray direction from the first template area to the second template area, when the grating template forms a grating structure, the spacing between any two adjacent grating transition portions 4 can increase or decrease along the direction from the grating area to the non-grating area. This allows for a gradual change in the density of 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, so that it can appear as a gradual reduction in the pattern area, forming a visually natural boundary attenuation, thereby effectively avoiding insufficient filling caused by abrupt height changes, and 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 an increasing pattern structure, which is beneficial for filling the imprinted adhesive, thereby effectively avoiding insufficient filling caused by abrupt height changes, and improving defects such as voids 5 and white edges 6.

[0092] In some embodiments, the number of transition forming parts provided in each transition template area is the same. Alternatively, the number of transition forming parts provided in each transition template area is different.

[0093] In some embodiments, the shape of the transition forming portion provided in each transition template area is the same.

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

[0096] Understandably, by increasing the number of transition molding portions located in different transition template areas along the same ray direction from the first template area to the second template area, when the grating template forms a grating structure, the number of grating transition portions 4 located in different transition areas 31 along the direction from the grating area to the non-grating area can also increase. Thus, all the grating transition portions 4 can form a pattern structure with increasing density, which is beneficial for filling the imprinted adhesive and effectively avoids insufficient filling caused by height abrupt changes, thereby 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 area of ​​all transition forming parts located in different transition template areas decreases.

[0098] It is understandable that by decreasing the total cross-sectional area of ​​all transition molding parts located in different transition template areas, when the grating template forms a grating structure, the total cross-sectional area of ​​all grating transition parts 4 located in different transition zones 31 can also decrease. The decrease in total cross-sectional area can make all grating transition parts 4 visually achieve a natural boundary attenuation, thereby effectively avoiding the phenomenon of insufficient filling caused by abrupt height changes, and improving defects such as voids 5 and white edges 6.

[0099] In some embodiments, the transition forming section 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, and the trapezoidal forming section is connected to the opposite ends of the rectangular forming section in the second direction, with the larger end of the trapezoidal forming section connected to the rectangular forming section. Alternatively, the trapezoidal forming section is connected to the opposite ends of the first template area in the second direction, with the larger end of the trapezoidal forming section connected to the grating stripe 11 forming section of the first template area, wherein the first direction and the second direction are set at an angle.

[0100] It is understandable that the rectangular forming section can form a rectangular transition segment 41, and the trapezoidal forming section can form a trapezoidal transition segment 42. Therefore, the grating transition section 4 can be divided into a rectangular transition segment 41 and a trapezoidal transition segment 42. The rectangular transition segment 41 is spaced apart from the grating area, so that it is spaced apart from the grating stripes 11 within the grating area and arranged identically, ensuring that the grating period and direction remain unchanged in the rectangular transition section. The trapezoidal transition segment 42 gives the grating transition section 4 a gradually decreasing width characteristic, thus making the overall image area of ​​the grating transition section 4 gradually decrease, forming a visually natural boundary attenuation, thereby effectively avoiding insufficient filling caused by abrupt height changes, and improving defects such as holes 5 and white edges 6.

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

[0102] In some embodiments, a grating stripe 11 forming section is provided in the first template area, 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 correspondingly forms the grating stripe 11, and the transition forming section correspondingly forms the grating transition section 4, thereby making the grating transition section 4 parallel to the grating stripe 11 in the first region 1. Thus, the grating transition section 4 can maintain the grating period and direction unchanged.

[0103] According to a fourth aspect of this application, a grating imprinting method is provided, which uses a grating template as described in the above embodiments to imprint a grating pattern. This grating imprinting method possesses all the beneficial effects of the aforementioned grating template, which will not be elaborated further herein.

[0104] The grating imprinting method in this embodiment 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 press the soft template with the substrate coated with the imprinting adhesive.

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

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

[0109] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying 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, "multiple" means two or more, unless otherwise explicitly specified.

[0110] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0111] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0112] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A grating structure, characterized in that, It 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 arranged around 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). The grating transition section (4) is provided in at least two parts and is distributed at intervals within the third region (3); Along the same ray direction from the first region (1) to the second region (2), the cross-sectional area of ​​at least two of the grating transition portions (4) decreases; The grating transition section (4) maintains the same pattern period and direction as the grating stripes (11) in the first region (1).

2. The grating structure according to claim 1, characterized in that, Along the same ray direction from the first region (1) to the second region (2), the width of at least two of the grating transition portions (4) decreases, and / or the length of at least two of the grating transition portions (4) decreases.

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

4. The grating structure according to claim 1, characterized in that, The third region (3) includes at least two transition regions (31), and at least two grating transition portions (4) are provided in each transition region (31) at intervals. 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.

5. The grating structure according to claim 4, characterized in that, 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 regions (31) decreases.

6. The grating structure according to claim 1, characterized in that, The grating transition section (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). 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 stripe (11) of the first region (1). The first direction is the width direction of the grating transition section (4), and the second direction is the length direction of the grating transition section (4).

7. An optical waveguide device, characterized in that, Includes the grating structure as described in any one of claims 1 to 6.

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