Jiaxing UPhoton Optoelectronics Technology Co., Ltd.

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 i th layer of waveguide medium being n i , an air refractive index being n 0 , and |n i −n i−1 |≥0.05.

A laser projection module includes an illumination light source and a micro-lens array. The micro-lens array includes a plurality of micro-lenses arranged at a first pitch P. In a working mode of projecting a spot array light field, a working distance D 1 of the micro-lens array relative to the light source satisfies the following equation: D 1 = NP 2 2 ⁢ λ + α ⁢ f where N is a positive integer, preferably N≤5; λ is the wavelength of light from the light source; α is a coefficient, 0<α≤1; and f is a focal length of the micro-lens. By selecting and optimizing the coefficient α for the focal length of the micro-lens, light energy of the spot array light field generated with the corresponding working distance is focused onto smaller spots, and thus contrast of laser spot array is improved.

A near-eye display waveguide device and a near-eye display apparatus are disclosed. The waveguide device comprises m waveguide substrates stacked on each other, m being an integer and m≥3. The device receives image-carrying light with an image field of view angle range, and the image-carrying light comprises light with less than m dominant wavelengths. Corresponding to each dominant wavelength, the m waveguide substrates are formed with at least two coupling-in gratings, the at least two coupling-in gratings are formed on different substrates and have different grating periods, for coupling light in different coupling-in field of view angle ranges into corresponding substrates, the coupling-in field of view angle ranges are each smaller than the image field of view angle range, and the coupling-in field of view angle ranges cover the image field of view angle range as a whole.

A diffractive optical waveguide, a design method for the diffractive optical waveguide, and a display device are provided. The diffractive optical waveguide includes a waveguide substrate and a coupling-in grating. The coupling-in grating includes a plurality of coupling-in grating blocks arranged randomly and continuously, the plurality of coupling-in grating blocks have the same period, and at least two coupling-in grating blocks of the plurality of coupling-in grating blocks have different duty cycles; a first coupling-in grating block of the at least two coupling-in grating blocks includes a plurality of grating units, and each grating unit has a first duty cycle; a second coupling-in grating block of the at least two coupling-in grating blocks includes a plurality of grating units, and each grating unit has a second duty cycle; the first duty cycle is different from the second duty cycle.

A diffractive optical waveguide, a design method for the diffractive optical waveguide, and a display device are provided. The diffractive optical waveguide includes a waveguide substrate and a coupling-in grating. The coupling-in grating includes a plurality of coupling-in grating blocks arranged randomly and continuously, the plurality of coupling-in grating blocks have the same period, and at least two coupling-in grating blocks of the plurality of coupling-in grating blocks have different duty cycles; a first coupling-in grating block of the at least two coupling-in grating blocks includes a plurality of grating units, and each grating unit has a first duty cycle; a second coupling-in grating block of the at least two coupling-in grating blocks includes a plurality of grating units, and each grating unit has a second duty cycle; the first duty cycle is different from the second duty cycle.

A near-eye display waveguide device and a near-eye display apparatus are disclosed. The waveguide device comprises m waveguide substrates stacked on each other, m being an integer and m≥3. The device receives image-carrying light with an image field of view angle range, and the image-carrying light comprises light with less than m dominant wavelengths. Corresponding to each dominant wavelength, the m waveguide substrates are formed with at least two coupling-in gratings, the at least two coupling-in gratings are formed on different substrates and have different grating periods, for coupling light in different coupling-in field of view angle ranges into corresponding substrates, the coupling-in field of view angle ranges are each smaller than the image field of view angle range, and the coupling-in field of view angle ranges cover the image field of view angle range as a whole.

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.

A method for increasing speckle spot density, comprising: acquiring light splitting dot array, which is used for performing array copying on multi-point light source and projection to form speckle spot array; acquiring minimum neighboring point spacing or average value of neighboring point spacing of all or part of light-emitting points in the multi-point light source; dividing light splitting dot array into first light splitting dot array and second light splitting dot array, speckle spot array formed by projection by first light splitting dot array being located in first speckle spot area, and speckle spot array formed by projection by second light splitting dot array being located in second speckle spot area; and performing expansive copying on each light splitting dot in second light splitting dot array so as to form third light splitting dot array.

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.

A design method for a diffractive optical element for beam splitting, comprising: S 11 , determining an input light field distribution and a target output light field distribution of a diffractive optical element; S 12 , constructing a beam splitting lattice of the diffractive optical element, wherein the light splitting lattice is used for performing array replication on light sources to realize the speckle lattice in a specific field of view, and the arrangement mode of the beam splitting lattice is regular arrangement or longitudinal and/or transverse periodic staggered arrangement; S 13 , disturbing the beam splitting lattice to reduce a deviation between an actual output light field and the target output light field, and limiting the disturbance quantity to ensure that there is no obvious overlap or gap between adjacent blocks in the speckle lattice; and S 14 , designing the diffractive optical element according to the disturbed beam splitting lattice.