Abstract: A diffractive optical waveguide is disclosed, in which a grating structure comprises a plurality of optical unit structures arranged in an array, a cross-section of an optical unit structure has a shape with two small ends and a large middle part, length L and maximum width W of the cross-section satisfy 0.2L?W?0.8L, and contour curves each are formed between an upper vertex and a left vertex, the upper vertex and a right vertex, a lower vertex and the left vertex, and the lower vertex and the right vertex, respectively. A display device comprising the same and a design and formation method for the same are also disclosed. The cross-section of the optical unit structure has a curved contour, with edges which are smooth and have very good processability. Also, the cross-section with curve contour of the optical unit structure has a very high degree of design freedom.

Abstract: The present application provides a display device and glasses. The display device includes an optical waveguide, a first and second projectors, at least one optical sensing assembly, and a feedback tracking device. The first and second projectors respectively project a first light with a wavelength of visible light wavelength and a second light with a wavelength of second wavelength to a coupling-in device. The optical sensing assembly is arranged corresponding to a coupling-out device, and includes at least one imaging device. The feedback tracking device is electrically connected to the first projector and the light sensing assembly. The optical sensing assembly is used for receiving the second light reflected by human eye. The feedback tracking device adjusts the first projector according to the second light received by the optical sensing assembly such that the first light coupled out of the coupling-out device follows a line of sight of human eye.

Abstract: A method for designing a diffractive optical element comprises: determining parameters of a light source and a target light field of a diffractive optical element; according to the parameters of the light source, determining the distribution of a plurality of first microstructure units on the diffractive optical element; dividing the target light field into a plurality of target maps superimposed to form the target light field, the first microstructure units corresponding to the target maps; performing distortion pre-correction on the plurality of target maps separately; and according to the plurality of corrected target maps and the parameters of the light source, designing corresponding phase distributions of the plurality of first microstructure units separately. A VCSEL partitioned light source may be combined with a diffractive optical element to project a uniform light field. The diffractive optical element is applied to a partitioned illumination system, which provides a uniform illumination.

Abstract: An optical waveguide device and a display device are provided. The optical waveguide device includes a waveguide substrate having a coupling-out region and first and second surfaces with coupling-in and reflection regions, a coupling-in grating disposed in the coupling-in region to diffract input light to form positive first-order and zero-order diffraction light, a coupling-out grating disposed and a reflection grating disposed in the reflection region such that portion of the zero-order diffraction light forms positive first-order reflection light through diffraction. A light spot of the zero-order diffraction light first projected onto the second surface has a first profile at least partially located in the reflection region. A projection of the reflection region on the first surface partially overlaps with the coupling-in region, and a ratio of area of an overlapping portion to that of the coupling-in region is less than or equal to 40%.

Abstract: The present application provides a display device and glasses. The display device includes an optical waveguide, a first and second projectors, at least one optical sensing assembly, and a feedback tracking device. The first and second projectors respectively project a first light with a wavelength of visible light wavelength and a second light with a wavelength of second wavelength to a coupling-in device. The optical sensing assembly is arranged corresponding to a coupling-out device, and includes at least one imaging device. The feedback tracking device is electrically connected to the first projector and the light sensing assembly. The optical sensing assembly is used for receiving the second light reflected by human eye. The feedback tracking device adjusts the first projector according to the second light received by the optical sensing assembly such that the first light coupled out of the coupling-out device follows a line of sight of human eye.

Abstract: An optical waveguide and a display device are provided. The optical waveguide includes a waveguide substrate causing light to propagate within it through total internal reflection and at least one grating disposed between and inclined with respect to the first and second surfaces of the waveguide substrate for transmitting and reflecting incident light or for transmitting and diffractively deflecting incident light. The transmitted light is coupled into the waveguide substrate to propagate within it through total internal reflection, and the reflected or diffractively deflected light is coupled out from the waveguide substrate. The grating is configured such that the reflection efficiency or diffraction deflection efficiency when an incidence angle is less than a first angle and greater than a fourth angle is greater than that when the incidence angle is greater than the first angle, wherein the first angle is greater than the fourth angle.

Abstract: A grating structure, a diffraction optical waveguide, and a display device are disclosed. The grating line of the grating structure has a cross-sectional profile with a narrow top and a wide bottom, wherein the cross-sectional profile comprises six feature points, and the six feature points respectively have coordinates (0, 0), (L2, H2), (L3, H3), (L4, H4), (L5, H5) and (L6, 0) in a cross section, and satisfy following relationships: Hdrop=min(H4,H5)?max(H3,H2)>50 nm; 0.1<(L5?L4)/(L3?L2); L3>0.34T; and 0.05T<L5?L4<0.32T. By controlling the parameters of these feature points, the cross-sectional profile can be adjusted, and thus significantly improving the optical effect (comprising diffraction efficiency and uniformity) that the grating structure can achieve, and at the same time increasing degrees of freedom in grating design and optical effect regulation.

Abstract: The application discloses an optical waveguide device for image display and a display device. The optical waveguide device comprises a coupling-in grating and a coupling-out grating provided on a waveguide substrate. The coupling-out grating is used to couple, at least a portion of light propagating into it along an input direction, out of the waveguide substrate, and has a receiving end located upstream and a coupling-out end located downstream along the input direction. The receiving end is divided into a first grating area, a second grating area and a blank area between the first and second grating areas in a width direction perpendicular to the input direction. The blank area can prevent central light from being prematurely diffracted and splitted by the coupling-out grating, thereby reducing the loss of light energy while ensuring effective coupling-out into an eyebox range, maximizing coupling-out efficiency, and improving the optical effect.

Abstract: The present application discloses an optical waveguide device, which comprises a waveguide substrate and a coupling-in grating and a coupling-out grating arranged on the waveguide substrate, and the coupling-in grating is configured to couple an input light beam from the outside of the waveguide substrate into the waveguide substrate so that the input light beam can be transmitted to the coupling-out grating through total reflection. Wherein the coupling-in grating has a grating vector direction pointing to the coupling-out grating, and the coupling-out grating includes a one-dimensional region in which a one-dimensional grating is formed and a two-dimensional region in which a two-dimensional grating is formed. The application further discloses display equipment comprising the optical waveguide device.

Abstract: A method for designing a diffractive optical element comprises: determining parameters of a light source and a target light field of a diffractive optical element; according to the parameters of the light source, determining the distribution of a plurality of first microstructure units on the diffractive optical element; dividing the target light field into a plurality of target maps superimposed to form the target light field, the first microstructure units corresponding to the target maps; performing distortion pre-correction on the plurality of target maps separately; and according to the plurality of corrected target maps and the parameters of the light source, designing corresponding phase distributions of the plurality of first microstructure units separately. A VCSEL partitioned light source may be combined with a diffractive optical element to project a uniform light field. The diffractive optical element is applied to a partitioned illumination system, which provides a uniform illumination.

Abstract: The application discloses an optical waveguide device for image display and a display device. The optical waveguide device comprises a coupling-in grating and a coupling-out grating provided on a waveguide substrate. The coupling-out grating is used to couple, at least a portion of light propagating into it along an input direction, out of the waveguide substrate, and has a receiving end located upstream and a coupling-out end located downstream along the input direction. The receiving end is divided into a first grating area, a second grating area and a blank area between the first and second grating areas in a width direction perpendicular to the input direction. The blank area can prevent central light from being prematurely diffracted and splited by the coupling-out grating, thereby reducing the loss of light energy while ensuring effective coupling-out into an eyebox range, maximizing coupling-out efficiency, and improving the optical effect.

Abstract: The disclosure provides a diffraction optical waveguide, a design method thereof and a near-eye display device. The diffraction optical waveguide includes: a waveguide substrate; a coupling-in grating configured to couple image light into the waveguide substrate through diffraction; and a coupling-out grating configured to couple at least a part of diffracted light propagating thereinto out of the waveguide substrate through diffraction, wherein the waveguide substrate includes M layers of waveguide media, a catadioptric interface is formed between adjacent waveguide media, the diffracted light passes through the M layers of waveguide media in sequence and is split by the catadioptric interface, beams after light splitting propagate towards a coupling-out zone along different transmission paths in the M layers of waveguide media, each layer of waveguide medium has a different refractive index, a refractive index of an ith layer of waveguide medium being ni, an air refractive index being n0, and |ni?ni?1|?0.

Abstract: The present application provides a diffractive optical waveguide for optical pupil expansion and a display device. The diffractive optical waveguide for optical pupil expansion comprises a waveguide substrate; a coupling-out grating disposed on or in the waveguide substrate and configured to couple input light out of the waveguide substrate by diffraction, wherein the coupling-out grating comprises a plurality of grating lines with widths; the plurality of grating lines are spaced in a cycle of a first predetermined period along a first direction and are spaced in a cycle of a second predetermined period along a second direction; each of the grating lines comprises a plurality of periodic structures in continuous and connected arrangement. Each of the periodic structures comprises a first edge and a second edge spaced in the first direction. The first predetermined period is defined as the distance between the first edge and the second edge in the first direction.

Abstract: A diffractive optical waveguide for optical pupil expansion and a display device are provided. The diffractive optical waveguide comprises a waveguide substrate and a grating structure. The grating structure is disposed on a surface of the waveguide substrate or in the waveguide substrate and comprises a plurality of periodic structures arranged at intervals along a first direction and arranged at intervals along a second direction. The second direction is different from the first direction. A first distance between the centers of adjacent periodic structures in the first direction is smaller than a second distance between the centers of adjacent periodic structures in the second direction. The grating structure is equivalent to a one-dimensional grating with a grating vector in a vertical direction of the first direction, and the vertical direction is parallel to a plane where the grating structure is located.

Abstract: The disclosure provides a diffraction optical waveguide, a design method thereof and a near-eye display device. The diffraction optical waveguide includes: a waveguide substrate; a coupling-in grating configured to couple image light into the waveguide substrate through diffraction; and a coupling-out grating configured to couple at least a part of diffracted light propagating thereinto out of the waveguide substrate through diffraction, wherein the waveguide substrate includes M layers of waveguide media, a catadioptric interface is formed between adjacent waveguide media, the diffracted light passes through the M layers of waveguide media in sequence and is split by the catadioptric interface, beams after light splitting propagate towards a coupling-out zone along different transmission paths in the M layers of waveguide media, each layer of waveguide medium has a different refractive index, a refractive index of an ith layer of waveguide medium being ni, an air refractive index being n0, and |ni?ni?1|?0.

Abstract: The application discloses an optical waveguide device for image display and a display device. The optical waveguide device comprises a coupling-in grating and a coupling-out grating provided on a waveguide substrate. The coupling-out grating is used to couple, at least a portion of light propagating into it along an input direction, out of the waveguide substrate, and has a receiving end located upstream and a coupling-out end located downstream along the input direction. The receiving end is divided into a first grating area, a second grating area and a blank area between the first and second grating areas in a width direction perpendicular to the input direction. The blank area can prevent central light from being prematurely diffracted and splited by the coupling-out grating, thereby reducing the loss of light energy while ensuring effective coupling-out into an eyebox range, maximizing coupling-out efficiency, and improving the optical effect.

Abstract: An optical waveguide device is disclosed, in which an input section comprises a first waveguide substrate and a first relief grating formed on a surface thereof, and refractive indices n1, n2 of the first relief grating and the first waveguide substrate satisfy n2<n1, such that a first maximum average number of reflections that a light beam within a predetermined FOV range is subjected to on the surface after diffraction of the predetermined order before leaving a region where the first relief grating lies, is N, and N?2, wherein when N?1, N?M?0.25; when 1<N?1.5, N?M?0.5; and when 1.5<N?2, N?M?0.75, wherein M is a second maximum average number of reflections assuming the first waveguide substrate has the same refractive index as the first relief grating.

Abstract: A diffraction optical waveguide is disclosed, which comprises a grating structure formed on a waveguide substrate. The grating structure comprises a plurality of optical unit structures arranged in an array along a plane; the optical unit structure has a first end and a second end in a first direction parallel to the plane, a distance between the two ends along the first direction is a length L of the optical unit structure; it has a maximum width W perpendicular to the first direction in a predetermined section along the first direction, where 0.3L?W?0.7L, and a central position of the predetermined section is at a predetermined distance d from the first end in the first direction, where d<0.5L; and a width gradually decreases from the predetermined section to both ends, so that a centroid of a cross-section of the optical unit structure is closer to the first end.

Abstract: A grating structure, a diffraction optical waveguide, and a display device are disclosed. The grating line of the grating structure has a cross-sectional profile with a narrow top and a wide bottom, wherein the cross-sectional profile comprises six feature points, and the six feature points respectively have coordinates (0, 0), (L2, H2), (L3, H3), (L4, H4), (L5, H5) and (L6, 0) in a cross section, and satisfy following relationships: Hdrop=min(H4,H5)?max(H3,H2)>50 nm; 0.1<(L5?L4)/(L3?L2); L3>0.34T; and 0.05T<L5?L4<0.32T. By controlling the parameters of these feature points, the cross-sectional profile can be adjusted, and thus significantly improving the optical effect (comprising diffraction efficiency and uniformity) that the grating structure can achieve, and at the same time increasing degrees of freedom in grating design and optical effect regulation.

Abstract: The disclosure provides a design method of a coupling-out grating and the design method including: calculating a diffraction coupling-in angle, at which a light beam is diffracted and coupled into the optical waveguide body through the coupling-in grating, according to an angle at which the light beam is incident to the coupling-in grating, a wavelength of the light beam and a grating period of the coupling-in grating; calculating a distance between two adjacent coupling-out positions of the light beam; calculating a brightness difference rate of the light beam after being coupled out multiple times through the coupling-out grating according to the maximum diffraction efficiency of the coupling-out grating; and calculating the number of partitions of the coupling-out grating according to a length of the coupling-out grating, a sensitivity of a human eye to the light beam, the brightness difference rate, and the distance between the two adjacent coupling-out positions.