Diffraction optical waveguide and near-eye display device

Abstract

The invention provides a diffractive optical waveguide and near-eye display equipment. The diffractive optical waveguide comprises a waveguide substrate, a coupling-in grating region, a coupling-out grating region, a turning grating region and an additional grating region, the coupling-in grating area, the coupling-out grating area, the turning grating area and the additional grating area are arranged on the waveguide substrate, and the coupling-in grating area is adjacent to the turning grating area in the first direction. The coupling-out grating region is adjacent to the coupling-in grating region and the turning grating region in the second direction, and the additional grating region is adjacent to at least one of the turning grating region and the coupling-out grating region; the first direction is different from the second direction; after the light is coupled into the waveguide substrate in the coupling-in grating area, the light is transmitted to the coupling-out grating area after being sequentially acted by at least one of the turning grating area and the additional grating area, and is coupled out of the waveguide substrate through the coupling-out grating area, so that the light can be circularly transmitted in the waveguide substrate in a reciprocating manner, and the utilization rate of light beam energy of the light can be improved. And the optical efficiency of the diffraction optical waveguide is improved.

Description

Technical Field

[0001] This application relates to the field of near-eye display technology, and more particularly to a diffractive waveguide and a near-eye display device. Background Technology

[0002] Near-eye display devices can include augmented reality (AR) devices, mixed reality (MR) devices, and so on. Near-eye display devices can utilize optical waveguides to achieve their near-eye display function. Optical waveguides can include diffractive waveguides.

[0003] Currently, diffractive waveguides are widely used in near-eye displays. However, due to the physical characteristics of diffractive waveguides, light suffers losses during propagation inside them, which can easily lead to low optical efficiency. Summary of the Invention

[0004] This application provides a diffractive waveguide and a near-eye display device, which aims to improve the utilization rate of light beam energy by the diffractive waveguide, thereby improving the optical efficiency of the diffractive waveguide.

[0005] In a first aspect, this application provides a diffractive optical waveguide, which includes a waveguide substrate, a coupling-in grating region, a coupling-out grating region, a transition grating region, and an additional grating region. The coupled-in grating region, the coupled-out grating region, the transition grating region, and the additional grating region are disposed on the waveguide substrate. The coupled-in grating region is adjacent to the transition grating region in a first direction, and the coupled-out grating region is adjacent to both the coupled-in grating region and the transition grating region in a second direction. The additional grating region is adjacent to at least one of the transition grating region and the coupled-out grating region. The first direction and the second direction are different. After the light is coupled into the waveguide substrate in the coupling grating region, the light is transmitted to the coupling out grating region after passing through at least one of the turning grating region and the added grating region in sequence, and is coupled out of the waveguide substrate through the coupling out grating region.

[0006] Secondly, this application provides a near-eye display device, which includes the aforementioned diffractive waveguide.

[0007] This application provides a diffractive waveguide and a near-eye display device. When the diffractive waveguide includes an additional grating region adjacent to a transition grating region, the additional grating region can guide a portion of the light rays that would otherwise be lost in the transition transmission path corresponding to the transition grating region back to the effective transmission path. This allows the light to circulate repeatedly within the waveguide substrate before being coupled out through the coupling grating region. Correspondingly, when the additional grating region is adjacent to the coupling grating region, the diffractive waveguide can also guide a portion of the light rays that would otherwise be lost in the coupling transmission path corresponding to the coupling grating region back to the effective transmission path, and then coupled out through the coupling grating region. Based on the configuration of the diffractive waveguide in this application, the utilization rate of the light beam energy by the diffractive waveguide is improved, thereby enhancing the light efficiency of the diffractive waveguide. Attached Figure Description

[0008] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a schematic diagram of the structure of a diffractive waveguide provided in an embodiment of this application; Figure 2 This is a wave vector space loop diagram of a diffractive waveguide according to an embodiment of this application; Figure 3 This is a schematic diagram of the light transmission path of a diffractive waveguide involved in the related technology; Figure 4 This is a schematic diagram of a light transmission path of a diffractive waveguide according to an embodiment of this application; Figure 5 This is a schematic diagram of another light transmission path of the diffractive waveguide involved in an embodiment of this application; Figure 6 This is a schematic diagram of another light transmission path of a diffractive waveguide according to an embodiment of this application; Figure 7 This is a schematic diagram of the structure of a near-eye display device provided in an embodiment of this application.

[0010] Explanation of reference numerals in the attached figures: 10, near-eye display device; 100, diffractive waveguide; 110, waveguide substrate; 120, coupling grating region; 130, coupling out grating region; 140, turning grating region; 150, additional grating region; 151, first additional grating region; 152, second additional grating region; 153, third additional grating region. Detailed Implementation

[0011] 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 some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0012] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the described order. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0013] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0014] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a diffractive waveguide 100 provided in an embodiment of this application.

[0015] like Figure 1 As shown, the diffractive waveguide 100 includes a waveguide substrate 110, a coupling grating region 120, a coupling out grating region 130, a transition grating region 140, and an additional grating region 150.

[0016] The coupled-in grating region 120, the coupled-out grating region 130, the transition grating region 140, and the additional grating region 150 are disposed on the waveguide substrate 110. The coupled-in grating region 120 is adjacent to the transition grating region 140 in a first direction, and the coupled-out grating region 130 is adjacent to both the coupled-in grating region 120 and the transition grating region 140 in a second direction. The additional grating region 150 is adjacent to at least one of the transition grating region 140 and the coupled-out grating region 130. The first direction and the second direction are different.

[0017] After the light is coupled into the waveguide substrate 110 in the coupling grating region 120, the light is transmitted to the coupling out grating region 130 after passing through at least one of the bending grating region 140 and the additional grating region 150 in sequence, and is coupled out of the waveguide substrate 110 through the coupling out grating region 130.

[0018] For example, the added grating region 150 may be adjacent to the transition grating region 140. When the added grating region 150 and the transition grating region 140 are adjacent, the projection of the added grating region 150 onto the waveguide substrate 110 overlaps with the projection of the transition grating region 140 onto the waveguide substrate 110. For instance, at least one overlapping projection contour segment exists between the projections of the added grating region 150 and the transition grating region 140. Figure 1As shown, the added grating area 150 may include a first added grating area 151 and a second added grating area 152. Both the first added grating area 151 and the second added grating area 152 are adjacent to the transition grating area 140.

[0019] For example, the added grating region 150 can be adjacent to the coupling grating region 130. When the added grating region 150 is adjacent to the coupling grating region 130, the projection of the added grating region 150 onto the waveguide substrate 110 overlaps with the projection of the coupling grating region 130 onto the waveguide substrate 110. For instance, at least one overlapping projection profile segment exists between the projection of the added grating region 150 and the projection of the transition grating region 140. Figure 1 As shown, the added grating area 150 may include a third added grating area 153. The third added grating area 153 is adjacent to the coupled grating area 130.

[0020] Accordingly, the added grating region 150 can be adjacent to the transition grating region 140 and the coupling grating region 130. For example... Figure 1 As shown, the added grating area 150 may include a first added grating area 151, a second added grating area 152, and a third added grating area 153. The first added grating area 151 and the second added grating area 152 are both adjacent to the turning grating area 140, and the third added grating area 153 is adjacent to the coupling grating area 130.

[0021] like Figure 1 As shown, when the first direction and the second direction are different, the coupling grating region 120 is adjacent to the transition grating region 140 in the first direction, similar to how the coupling grating region 120 and the transition grating region 140 are longitudinally adjacent. The coupling out grating region 130 is adjacent to both the coupling grating region 120 and the transition grating region 140 in the second direction, similar to how the coupling out grating region 130 is laterally adjacent to the coupling grating region 120 and the transition grating region 140, respectively. When the coupling grating region 120 is adjacent to the transition grating region 140 in the first direction, there is no overlapping region between the projection of the coupling grating region 120 on the waveguide substrate 110 and the projection of the transition grating region 140 on the waveguide substrate 110. Accordingly, when the output grating region 130 is adjacent to the input grating region 120 and the transition grating region 140 in the second direction, the projection of the output grating region 130 on the waveguide substrate 110 does not overlap with the projections of the input grating region 120 and the transition grating region 140 on the waveguide substrate 110.

[0022] When light shines on the diffractive waveguide 100, the coupling grating region 120 of the diffractive waveguide 100 can couple the light into the waveguide substrate 110 of the diffractive waveguide 100. Then, the light can be transmitted to the coupling out grating region 130 of the diffractive waveguide 100 after passing through at least one of the turning grating region 140 and the additional grating region 150 of the diffractive waveguide 100, and then coupled out of the waveguide substrate 110 through the coupling out grating region 130.

[0023] For example, the first preset grating vector coupled into the grating region 120 can be represented as IG is used to indicate the coupled grating region 120. For example... Figure 2 As shown, the first preset grating vector satisfies: O is used to indicate the origin O in the wave vector spatial loop of the diffracting waveguide 100, and A is used to indicate point A in the wave vector spatial loop of the diffracting waveguide 100. The first preset grating period of the coupled grating region 120 can be expressed as: .

[0024] The second preset grating vector of the coupled grating region 130 can be expressed as: OG is used to indicate the coupling grating region 130. For example... Figure 2 As shown, the second preset grating vector satisfies: B is used to indicate point B in the wave vector spatial loop of the diffracting waveguide 100. The second preset grating period of the coupling grating region 130 can be expressed as... .

[0025] The third preset grating vector of the angular grating region 140 can be expressed as: FG is used to indicate the bend raster area 140. For example... Figure 2 As shown, the third preset grating vector satisfies: The third preset grating period of the transition grating region 140 can be expressed as: .

[0026] For example, the added grating area 150 may include at least one of the first added grating area 151, the second added grating area 152, and the third added grating area 153.

[0027] The first target grating vector of the first added grating region 151 can be expressed as: G1 is used to indicate the first added grating region 151. For example, the first target grating vector of the first added grating region 151 is n times the first preset grating vector coupled into the grating region 120; n is greater than or equal to 2. For instance, n includes integers corresponding to diffraction orders. For example, n can include 2, 3, 4, 5, etc., without limitation. Figure 2 As shown, the first target grating vector satisfies: D is used to indicate point D in the wave vector spatial loop of the diffractive waveguide 100. The direction of the first target vector corresponding to the first target grating vector is the same as the direction of the first preset vector corresponding to the first preset grating vector. The period of the first target grating in the first added grating region 151 can be expressed as: And the period of the first target grating satisfies: n is greater than or equal to 2.

[0028] The second target grating vector of the second added grating region 152 can be expressed as: G2 is used to indicate the second added grating region 152. For example, the second target grating vector of the second added grating region 152 is n times the second preset grating vector of the coupled grating region 130; n is greater than or equal to 2. For instance, n includes integers corresponding to diffraction orders. For example, n can include 2, 3, 4, 5, etc., without limitation. Figure 2 As shown, the second target grating vector satisfies: C is used to indicate point C in the wave vector spatial loop of the diffractive waveguide 100. The direction of the second target vector corresponding to the second target grating vector is the same as the direction of the second preset vector corresponding to the second preset grating vector. The period of the second target grating in the second added grating region 152 can be expressed as: And the period of the first target grating satisfies: n is greater than or equal to 2.

[0029] The third target grating vector of the third added grating region 153 can be expressed as: G3 is used to indicate the third additional grating region 153. For example, the third target grating vector of the third additional grating region 153 is n times the second preset grating vector of the coupled grating region 130; n is greater than or equal to 2. For instance, n includes integers corresponding to diffraction orders. For example, n can include 2, 3, 4, 5, etc., without limitation. Figure 2 As shown, the third target grating vector satisfies: The direction of the third target grating vector is the same as the direction of the second preset grating vector. The period of the second target grating in the second added grating area 152 can be expressed as... And the period of the first target grating satisfies: n is greater than or equal to 2.

[0030] In related technologies, a diffractive waveguide includes a waveguide substrate, a coupling grating region, a coupling out grating region, and a transition grating region; the coupling out grating region, the coupling out grating region, and the transition grating region are disposed on the waveguide substrate. For example... Figure 3 a and Figure 3As shown in b, when light shines on the diffractive waveguide in the related technology, the light transmission path of the diffractive waveguide in the related technology includes: the light is coupled into the waveguide substrate after being coupled into the coupling grating region (origin O), and then enters the transition grating region after being coupled into the coupling grating region (O→A), and then enters the transition grating region after being coupled into the transition grating region (A). B) After entering the coupling grating region, and after being acted upon by the coupling grating region (B→O), a portion of the light is coupled out from the coupling grating region (B→O). The coupled light can, for example, enter the human eye. Based on this, the propagation path of light in a diffractive waveguide can be represented as: (path) O→A B→O. Accordingly, in the related technology, the first preset grating vector coupled into the grating region, the second preset grating vector coupled out of the grating region, and the third preset grating vector of the transition grating region satisfy:

[0031]

[0032] However, in related technologies, during the modulation of light by the transition grating region, a portion of the light is easily lost in the transition transmission path corresponding to the transition grating region. Furthermore, during the modulation of light by the coupling grating region, a portion of the light is also easily lost in the coupling transmission path corresponding to the coupling grating region. Therefore, this often leads to lower optical efficiency of the diffractive waveguide in the related technologies.

[0033] For example, in this application, an additional grating region 150 is provided in the diffractive waveguide 100, and the additional grating region 150 is adjacent to the transition grating region 140. The additional grating region 150 can guide a portion of the light that is easily lost in the transition transmission path corresponding to the transition grating region 140 back to the effective transmission path, so that the light can be circulated and transmitted inside the waveguide substrate 110 and then coupled out through the coupling grating region 130, thereby improving the utilization rate of the beam energy of the diffractive waveguide 100 and thus improving the light efficiency of the diffractive waveguide 100.

[0034] In one embodiment, the added grating region 150 includes a first added grating region 151 and a second added grating region 152; in a first direction, the first added grating region 151 is adjacent to the transition grating region 140, and the transition grating region 140 is located between the coupled-in grating region 120 and the first added grating region 151; in a second direction, the second added grating region 152 is adjacent to the transition grating region 140, and the transition grating region 140 is located between the second added grating region 152 and the coupled-out grating region 130.

[0035] like Figure 1 as well as Figure 4As shown in Figure a, in the first direction, the first added grating region 151 is adjacent to the transition grating region 140, and the transition grating region 140 is located between the coupling grating region 120 and the first added grating region 151, similar to the first added grating region 151 and the transition grating region 140 being longitudinally adjacent, and the transition grating region 140 being longitudinally adjacent to the coupling grating region 120. When the first added grating region 151 and the transition grating region 140 are adjacent in the first direction, there is an overlapping area between the projection of the first added grating region 151 on the waveguide substrate 110 and the projection of the transition grating region 140 on the waveguide substrate 110. When the projection of the first added grating region 151 onto the waveguide substrate 110 contains two contour edges 1 and 2 arranged opposite each other in a first direction, and the projection of the transition grating region 140 onto the waveguide substrate 110 contains two contour edges 3 and 4 arranged opposite each other in a first direction, and contour edges 1 to 4 are sequentially adjacent in the first direction, the contour edge 2 of the first added grating region 151 overlaps with the contour edge 3 of the transition grating region 140, so that the first added grating region 151 is adjacent to the transition grating region 140 in the first direction. Of course, this is not the only possibility, and no limitation is made here.

[0036] like Figure 1 as well as Figure 4 As shown in Figure a, in the second direction, the second added grating region 152 is adjacent to the transition grating region 140, and the transition grating region 140 is located between the second added grating region 152 and the coupling grating region 130, similar to the second added grating region 152 and the transition grating region 140 being laterally adjacent, and the transition grating region 140 and the coupling grating region 130 being laterally adjacent. When the second added grating region 152 and the transition grating region 140 are adjacent in the second direction, there is an overlapping area between the projection of the second added grating region 152 onto the waveguide substrate 110 and the projection of the transition grating region 140 onto the waveguide substrate 110. When the projection of the second added grating region 152 onto the waveguide substrate 110 contains two contour edges 5 and 6 arranged opposite each other in the second direction, and the projection of the transition grating region 140 onto the waveguide substrate 110 contains two contour edges 7 and 8 arranged opposite each other in the second direction, and contour edges 5 to 8 are sequentially adjacent in the second direction, the contour edge 6 of the second added grating region 152 overlaps with the contour edge 7 of the transition grating region 140, so that the second added grating region 152 is adjacent to the transition grating region 140 in the second direction. Of course, this is not the only possibility, and no limitation is made here.

[0037] like Figure 4 a and Figure 4As shown in b, when light shines on the diffractive waveguide 100, the light transmission path of the diffractive waveguide 100 includes: the light is coupled into the waveguide substrate 110 after passing through the coupling grating region 120 (origin O), and then enters the transition grating region 140 after passing through the coupling grating region 120 (O→A), and then enters the transition grating region 140 after passing through the transition grating region 140 (A... B) After entering the coupling grating region 130, and after being acted upon by the coupling grating region 130 (B→O), a portion of the light is coupled out from the coupling grating region 130 (B→O). Based on this, the propagation path of the light in the diffractive waveguide 100 can be represented as: (Path 1) O→A B→O. Correspondingly, the first preset grating vector coupled into the grating region 120, the second preset grating vector coupled out of the grating region 130, and the third preset grating vector of the transition grating region 140 satisfy:

[0038]

[0039] like Figure 4 a and Figure 4 As shown in b, the light transmission path of the diffractive waveguide 100 further includes: after the light passes through the coupling grating region 120 (origin O), it is coupled into the waveguide substrate 110, and after passing through the coupling grating region 120 (O→A), it passes through the turning grating region 140. A portion of the light passes through the turning grating region 140 and enters the first additional grating region 151. After passing through the first additional grating region 151 (A→D), it returns to the turning grating region 140, and after passing through the turning grating region 140 (D... After C), the light enters the second added grating area 152, which can guide the light back to the turning grating area 140 (C→B), where it propagates along a grid path (B). A) A portion of the light enters the first added grating region 151, repeating the above path, while the other portion continues into the coupling grating region 130, and is coupled out after being acted upon by the coupling grating region 130 (B→O). Based on this, the propagation path of the light in the diffractive waveguide 100 can be represented as: (Path 2) O→A→D C→B A→O, (Repeating path 3) O→A→D C→B A→D C→B A→O. Correspondingly, the first preset grating vector coupled into the grating region 120, the second preset grating vector coupled out of the grating region 130, and the third preset grating vector of the transition grating region 140 satisfy:

[0040]

[0041] Based on this, the addition of the grating region 150, including the first addition grating region 151 and the second addition grating region 152, can guide a portion of the light that is easily lost in the turning transmission path corresponding to the turning grating region 140 back to the effective transmission path, so that the light can be circulated and transmitted inside the waveguide substrate 110 and then coupled out through the coupling grating region 130, thereby improving the utilization rate of the beam energy of the diffractive waveguide 100 and thus improving the light efficiency of the diffractive waveguide 100.

[0042] For example, in this application, an additional grating region 150 is provided in the diffractive waveguide 100, and the additional grating region 150 is adjacent to the coupling grating region 130. The additional grating region 150 can guide a portion of the light that is easily lost in the coupling transmission path corresponding to the coupling grating region 130 back to the effective transmission path, and then couple out through the coupling grating region 130, so as to improve the utilization rate of the beam energy of the diffractive waveguide 100, thereby improving the light efficiency of the diffractive waveguide 100.

[0043] In one embodiment, the added grating region 150 includes a third added grating region 153; in the second direction, the third added grating region 153 is adjacent to the coupled grating region 130, and the coupled grating region 130 is located between the transition grating region 140 and the third added grating region 153.

[0044] like Figure 1 as well as Figure 5 As shown in Figure a, in the second direction, the third added grating region 153 is adjacent to the coupling grating region 130, and the coupling grating region 130 is located between the turning grating region 140 and the third added grating region 153, similar to the third added grating region 153 being laterally adjacent to the coupling grating region 130, and the coupling grating region 130 being laterally adjacent to the turning grating region 140. When the third added grating region 153 and the coupling grating region 130 are adjacent in the second direction, there is an overlapping area between the projection of the third added grating region 153 onto the waveguide substrate 110 and the projection of the coupling grating region 130 onto the waveguide substrate 110. In the projection of the third added grating region 153 onto the waveguide substrate 110, there are two contour edges 9 and 10 arranged opposite each other in the second direction. Similarly, in the projection of the coupling grating region 130 onto the waveguide substrate 110, there are two contour edges 11 and 12 arranged opposite each other in the second direction, and contour edges 9 to 12 are sequentially adjacent in the second direction. In this case, contour edge 10 of the third added grating region 153 overlaps with contour edge 11 of the coupling grating region 130, so that the third added grating region 153 is adjacent to the coupling grating region 130 in the second direction. However, this is not a limitation and is not specified herein.

[0045] like Figure 5a and Figure 5 As shown in b, when light shines on the diffractive waveguide 100, the light transmission path of the diffractive waveguide 100 includes: the light is coupled into the waveguide substrate 110 after passing through the coupling grating region 120 (origin O), and then enters the transition grating region 140 after passing through the coupling grating region 120 (O→A), and then enters the transition grating region 140 after passing through the transition grating region 140 (A... B) After entering the coupling grating region 130, and after being acted upon by the coupling grating region 130 (B→O), a portion of the light is coupled out from the coupling grating region 130 (B→O). Based on this, the propagation path of the light in the diffractive waveguide 100 can be represented as: (Path 1) O→A B→O. Correspondingly, the first preset grating vector coupled into the grating region 120, the second preset grating vector coupled out of the grating region 130, and the third preset grating vector of the transition grating region 140 satisfy:

[0046]

[0047] like Figure 5 a and Figure 5 As shown in b, the light transmission path of the diffractive waveguide 100 also includes: a portion of the light that does not couple out from the coupling grating region 130 continues into the third additional grating region 153, and after being acted upon by the third additional grating region 153 (B→C), it returns to the coupling grating region 130, and after being acted upon by the coupling grating, it couples out (C→O). Based on this, the light transmission path in the diffractive waveguide 100 can be represented as: (Path 2) O→A B→C→O. Correspondingly, the first preset grating vector coupled into the grating region 120, the second preset grating vector coupled out of the grating region 130, and the third preset grating vector of the transition grating region 140 satisfy:

[0048]

[0049] Based on this, the third additional grating region 153 included in the additional grating region 150 can guide a portion of the light that is easily lost in the coupled transmission path corresponding to the coupled grating region 130 back to the effective transmission path and coupled out through the coupled grating region 130, so as to improve the utilization rate of the beam energy of the diffractive waveguide 100, thereby improving the light efficiency of the diffractive waveguide 100.

[0050] In one embodiment, the third additional grating region 153 is also adjacent to the coupled grating region 130 in the first direction.

[0051] like Figure 1 as well as Figure 5As shown in Figure a, in the first direction, the third added grating region 153 is adjacent to the coupling grating region 130, similar to the longitudinal adjacency of the third added grating region 153 and the coupling grating region 130, and the coupling grating region 130 is longitudinally adjacent to the turning grating region 140. When the third added grating region 153 and the coupling grating region 130 are adjacent in the first direction, there is an overlapping area between the projection of the third added grating region 153 onto the waveguide substrate 110 and the projection of the coupling grating region 130 onto the waveguide substrate 110. When the projection of the third added grating region 153 onto the waveguide substrate 110 contains two contour edges 13 and 14 arranged opposite each other in the first direction, and the projection of the coupling grating region 130 onto the waveguide substrate 110 contains two contour edges 15 and 16 arranged opposite each other in the first direction, and contour edges 13 to 16 are sequentially adjacent in the first direction, the contour edge 14 of the third added grating region 153 overlaps with the contour edge 15 of the coupling grating region 130, so that the third added grating region 153 is adjacent to the coupling grating region 130 in the first direction. Of course, this is not the only possibility, and no limitation is made here.

[0052] like Figure 5 a and Figure 5 As shown in b, when the third additional grating region 153 is still adjacent to the coupling grating region 130 in the first direction, the third additional grating region 153 can more comprehensively cover the light rays that have not been coupled out from the coupling grating region 130, so that the light rays that have not been coupled out from the coupling grating region 130 can continue to enter the third additional grating region 153, and after being acted upon by the third additional grating region 153 (B→C), return to the coupling grating region 130, and be coupled out after being acted upon by the coupling grating (C→O).

[0053] Based on this, the third additional grating region 153 included in the additional grating region 150 can guide a portion of the light that is easily lost in the coupled transmission path corresponding to the coupled grating region 130 back to the effective transmission path and coupled out through the coupled grating region 130, so as to improve the utilization rate of the beam energy of the diffractive waveguide 100, thereby improving the light efficiency of the diffractive waveguide 100.

[0054] In one embodiment, the added grating area 150 includes a first added grating area 151, a second added grating area 152, and a third added grating area 153.

[0055] like Figure 6 a and Figure 6As shown in b, when the added grating region 150 includes a first added grating region 151, a second added grating region 152, and a third added grating region 153, the light transmission path in the diffractive waveguide 100 can be determined by combining the light transmission paths of the diffractive waveguide 100 when the added grating region 150 includes the first added grating region 151 and the second added grating region 152 in the aforementioned embodiments, and the light transmission path of the diffractive waveguide 100 when the added grating region 150 includes the third added grating region 153. This will not be elaborated further here. Correspondingly, the first preset grating vector coupled into the grating region 120, the second preset grating vector coupled out of the grating region 130, and the third preset grating vector of the turning grating region 140 can also be determined by combining the aforementioned embodiments. This will not be elaborated further here.

[0056] Based on this, the added grating region 150, including the first added grating region 151 and the second added grating region 152, can guide a portion of the light that is easily lost in the turning transmission path corresponding to the turning grating region 140 back to the effective transmission path, so that the light can circulate repeatedly within the waveguide substrate 110 and then be coupled out through the coupling grating region 130. Furthermore, the added grating region 150, including the third added grating region 153, can guide a portion of the light that is easily lost in the coupling transmission path corresponding to the coupling grating region 130 back to the effective transmission path and be coupled out through the coupling grating region 130. The addition of the grating region 150 in the diffractive waveguide 100 helps to improve the utilization rate of the light beam energy of the diffractive waveguide 100, thereby improving the light efficiency of the diffractive waveguide 100.

[0057] In one embodiment, the projected area of ​​the grating region 150 on the waveguide substrate 110 is less than or equal to at least one of the projected areas of the transition grating region 140 on the waveguide substrate 110 and the projected areas of the coupling grating region 130 on the waveguide substrate 110.

[0058] For example, such as Figure 1 As shown, when the added grating region 150 includes a first added grating region 151 and a second added grating region 152, the projected area of ​​the first added grating region 151 on the waveguide substrate 110 is less than or equal to the projected area of ​​the transition grating region 140 on the waveguide substrate 110, and the projected area of ​​the second added grating region 152 on the waveguide substrate 110 is less than or equal to the projected area of ​​the transition grating region 140 on the waveguide substrate 110.

[0059] For example, such as Figure 1 As shown, when the added grating region 150 includes a third added grating region 153, the projected area of ​​the third added grating region 153 on the waveguide substrate 110 is less than or equal to the projected area of ​​the coupling grating region 130 on the waveguide substrate 110.

[0060] When the projected area of ​​the added grating region 150 on the waveguide substrate 110 is less than or equal to at least one of the projected areas of the transition grating region 140 and the coupling grating region 130 on the waveguide substrate 110, the diffracting waveguide 100 can improve the utilization rate of light beam energy by using the added grating region 150 with a smaller projected area. This is beneficial for improving the light efficiency of the diffracting waveguide 100 while ensuring its miniaturization. Furthermore, when the diffracting waveguide 100 can improve the utilization rate of light beam energy by using the added grating region 150 with a smaller projected area, it is beneficial for improving the design flexibility of the diffracting waveguide 100.

[0061] In the above embodiment, when the added grating region 150 is provided and is adjacent to the transition grating region 140, the diffractive waveguide 100 can use the added grating region 150 to guide a portion of the light that is easily lost in the transition transmission path corresponding to the transition grating region 140 back to the effective transmission path, so that the light can circulate repeatedly within the waveguide substrate 110 and then be coupled out through the coupling grating region 130. Correspondingly, when the added grating region 150 is adjacent to the coupling grating region 130, the diffractive waveguide 100 can also use the added grating region 150 to guide a portion of the light that is easily lost in the coupling transmission path corresponding to the coupling grating region 130 back to the effective transmission path, and then be coupled out through the coupling grating region 130. Based on the configuration of the diffractive waveguide 100 in this application, it is beneficial to improve the utilization rate of the beam energy of the diffractive waveguide 100, thereby improving the light efficiency of the diffractive waveguide 100.

[0062] Please see Figure 7 , Figure 7 This is a schematic diagram of the structure of a near-eye display device 10 provided in an embodiment of this application.

[0063] In one embodiment, the near-eye display device 10 includes a diffractive waveguide 100 as provided in any of the embodiments described above.

[0064] It should be understood that, in any of the embodiments described above, when the diffractive waveguide 100 is provided with an additional grating region 150, and the additional grating region 150 is adjacent to the transition grating region 140, the diffractive waveguide 100 can use the additional grating region 150 to guide a portion of the light that is easily lost in the transition transmission path corresponding to the transition grating region 140 back to the effective transmission path, so that the light can circulate repeatedly within the waveguide substrate 110 and then be coupled out through the coupling grating region 130. Correspondingly, when the additional grating region 150 is adjacent to the coupling grating region 130, the diffractive waveguide 100 can also use the additional grating region 150 to guide a portion of the light that is easily lost in the coupling transmission path corresponding to the coupling grating region 130 back to the effective transmission path, and then be coupled out through the coupling grating region 130. Based on the configuration of the diffractive waveguide 100 in this application, it is beneficial to improve the utilization rate of the beam energy of the diffractive waveguide 100, thereby improving the light efficiency of the diffractive waveguide 100. The specific structure and implementation principle of the diffractive waveguide 100 included in the near-eye display device 10 can be found in the preceding text and will not be described again here.

[0065] For example, the near-eye display device 10 includes AR devices, such as AR glasses, AR helmets, etc.; the near-eye display device 10 may also include mixed reality (MR) devices, such as MR glasses, MR helmets, etc., without limitation.

[0066] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0067] It should also be understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. It should be noted that, herein, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0068] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. The above descriptions are merely specific implementations of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A diffractive optical waveguide, characterized in that, The diffractive waveguide includes a waveguide substrate, a coupling-in grating region, a coupling-out grating region, a transition grating region, and an additional grating region. The coupled-in grating region, the coupled-out grating region, the transition grating region, and the additional grating region are disposed on the waveguide substrate. The coupled-in grating region is adjacent to the transition grating region in a first direction, and the coupled-out grating region is adjacent to both the coupled-in grating region and the transition grating region in a second direction. The additional grating region is adjacent to at least one of the transition grating region and the coupled-out grating region. The first direction and the second direction are different. After the light is coupled into the waveguide substrate in the coupling grating region, the light is transmitted to the coupling out grating region after passing through at least one of the turning grating region and the added grating region in sequence, and is coupled out of the waveguide substrate through the coupling out grating region.

2. The diffractive waveguide according to claim 1, characterized in that, The added grating area includes a first added grating area and a second added grating area; In a first direction, the first added grating region is adjacent to the turning grating region, and the turning grating region is located between the coupling grating region and the first added grating region; In the second direction, the second added grating region is adjacent to the turning grating region, and the turning grating region is located between the second added grating region and the coupling grating region.

3. The diffractive waveguide according to claim 2, characterized in that, The first target grating vector of the first added grating region is n times the first preset grating vector of the coupled grating region; and / or, The second target grating vector of the second added grating area is n times the second preset grating vector of the coupled grating area; n is greater than or equal to 2.

4. The diffractive waveguide according to claim 3, characterized in that, The direction of the first target vector corresponding to the first target grating vector is the same as the direction of the first preset vector corresponding to the first preset grating vector; and / or, The direction of the second target vector corresponding to the second target grating vector is the same as the direction of the second preset vector corresponding to the second preset grating vector.

5. The diffractive waveguide according to any one of claims 1 to 4, characterized in that, The added grating area includes a third added grating area; In the second direction, the third additional grating region is adjacent to the coupling grating region, and the coupling grating region is located between the turning grating region and the third additional grating region.

6. The diffractive waveguide according to claim 5, characterized in that, The third additional grating region is also adjacent to the coupled grating region in the first direction.

7. The diffractive waveguide according to claim 5, characterized in that, The third target grating vector of the third added grating area is n times the second preset grating vector of the coupled grating area; n is greater than or equal to 1.5 and less than or equal to 3.

8. The diffractive waveguide according to claim 7, characterized in that, The direction of the third target vector corresponding to the third target grating vector is the same as the direction of the second preset vector corresponding to the second preset grating vector.

9. The diffractive waveguide according to any one of claims 1 to 4, characterized in that, The projected area of ​​the added grating region on the waveguide substrate is less than or equal to at least one of the projected area of ​​the transition grating region on the waveguide substrate and the projected area of ​​the added grating region on the waveguide substrate.

10. A near-eye display device, characterized in that, Includes the diffractive waveguide as described in any one of claims 1 to 9.

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