14results about How to "High diffraction efficiency" patented technology

The application discloses a calculation method for optimizing control parameters of a passive cascade liquid crystal polarization grating, and belongs to the technical field of liquid crystal polarization gratings. In order to solve the problem of low diffraction efficiency of the passive cascade polarization grating, the method comprises the following steps: calculating the layer control coefficient required by each layer of the cascade liquid crystal polarization grating at different deflection angles; calculating a sheet control coefficient of a liquid crystal adjustable half-wave plate; calculating a sheet applied voltage coefficient of each sheet of the liquid crystal adjustable half-wave plate from the emission end according to the sheet control coefficient and a polarization state of incident light, and establishing a sheet applied voltage coefficient set; and calculating a control voltage of each sheet of the liquid crystal adjustable half-wave plate according to the sheet control coefficient of each sheet of the liquid crystal adjustable half-wave plate and the angle of the incident light, so that the outgoing light of each layer is standard circularly polarized light, and a control voltage set of the cascade liquid crystal polarization grating is established. Under the premise of not changing the hardware structure, the sheet control coefficient, the sheet applied voltage coefficient and the sheet control voltage of each layer of the liquid crystal adjustable half-wave plate are optimized, and the problem of low diffraction efficiency of the passive cascade liquid crystal polarization grating is solved.

A diffraction grating is disclosed, which is used as an output element of a diffraction waveguide combiner for an augmented reality or virtual reality display. The grating includes an interlaced rectangular grating (1213) comprising a first rectangular periodic array of optical structures (1211) and a second rectangular periodic array of optical structures (1212) arranged in a plane. The first array of optical structures (1211) and the second array of optical structures (1212) differ from each other in at least one characteristic, or the first array of optical structures (1211) is offset relative to the second array of optical structures (1212) by a factor different from half the period of the first or second rectangular array, such that the first array of optical structures (1211) and the second array of optical structures (1212) are configured to receive light from an input direction and couple various orders of light in a direction angular to the input direction, and couple various orders of light out toward an observer.

This invention relates to a highly uniform optical waveguide structure, comprising a waveguide substrate, an imprinted adhesive layer disposed on the waveguide substrate, an integrally formed imprinted grating structure disposed on the imprinted adhesive layer, and a high-refractive-index dielectric layer disposed on the imprinted grating structure. The waveguide substrate is sequentially divided into a coupling-in region, a transition region, and a coupling-out region along the beam propagation path. The grating teeth of the imprinted grating structure located in the transition region and / or the coupling-out region are inserted into the high-refractive-index dielectric layer, and the refractive index of the high-refractive-index dielectric layer exceeds the refractive index of the imprinted grating structure. This invention solves the problem of low diffraction efficiency caused by the excessively low refractive index of the imprinted adhesive in optical waveguide structures fabricated by nanoimprinting, and has the advantages of improving the optical efficiency and uniformity of the optical waveguide structure.

The application provides a cyclohexanone photosensitizer shown in a formula I, a preparation method of the cyclohexanone photosensitizer, a mixed photosensitizer containing the cyclohexanone photosensitizer, a photopolymerization composition and a photopolymer film, wherein the cyclohexanone photosensitizer has the structural formula shown in the formula I, wherein R1 and R2 are each independently selected from hydrogen or C1-C4 alkyl. The cyclohexanone photosensitizer provided by the application replaces a benzene ring with thiophene, shows excellent absorption performance in a green laser wavelength range, is well matched with a 532nm laser, and provides more candidate photosensitizers for the development of green photosensitive polymer films.

The utility model relates to a kind of optical waveguide with double-sided coupling-out structure. Including: waveguide substrate, coupling-in unit, first coupling-out unit and second coupling-out unit, coupling-in unit and first coupling-out unit are located in the first surface of waveguide substrate, second coupling-out unit is set in the second surface of waveguide substrate opposite to first coupling-out unit, and second coupling-out unit is high-reflection-efficiency diffraction structure.Coupling-in unit is configured to couple image light into the waveguide substrate, part of the image light is diffracted by the first coupling-out unit, and the remaining light is reflected by the second coupling-out unit when it reaches the second coupling-out unit.

The invention discloses a visible light broadband edge detection system and a diffractive optical element design method, and relates to the technical field of optical neural networks. The system comprises an information input module which comprises a light source and a mask plate and is used for converting object information into intensity information of a light beam so as to obtain an input light field; the all-optical edge detection module comprises a 4f system and a diffractive optical element and is used for outputting a light field after phase modulation; and the information acquisition module acquires intensity information of an output light field through a photoelectric detector, and the output light field is subjected to phase modulation through a 4f system and a diffractive optical element, so that broadband edge detection is realized. According to the design of the diffractive optical element, a differentiable end-to-end light field transmission simulation model is established, differentiable mapping from diffraction element structure parameters to an output light field is achieved, and the diffraction element structure parameters are optimized based on the deep learning technology. According to the end-to-end reverse design method provided by the invention, all-optical broadband edge detection with high diffraction efficiency can be realized without physical priori knowledge.

This application discloses a laser beam combining system, including multiple wavelength-locked laser units, a beam compression unit, and a beam combining unit. The multiple wavelength-locked laser units can generate multiple parallel light bands, each containing multiple wavelength-locked and parallel beams. The beam compression unit includes multiple compression mirrors and a Galilean beam expander module. The compression mirrors reflect the light bands from the wavelength-locked laser units to the Galilean beam expander module, which compresses the spacing between the parallel beams. The beam combining unit is located downstream of the Galilean beam expander module and combines the multiple parallel beams for output. After the Galilean beam expander module compresses the spacing between the beams, the beams enter the beam combining unit and are combined into a high-power, high-brightness laser beam under the action of the beam combining unit. This eliminates the need for multiple fiber couplings and fiber fusion splices, thus reducing the number of optical components, lowering the assembly and adjustment complexity, reducing the size of the laser beam combining system, and reducing optical power loss.

The utility model relates to an acousto-optic device, which comprises an acousto-optic medium, and a bottom electrode, a piezoelectric transducer and a surface electrode which are positioned on a first surface of the acousto-optic medium and are sequentially arranged along a first direction deviating from the acousto-optic medium, the surface electrode comprises a working part, a connecting part and a welding part which are sequentially arranged along a second direction parallel to the first surface; the working part has a preset size, and the welding part extends to the first surface along the direction towards the acousto-optic medium; the bottom electrode comprises a groove with an opening opposite to the welding part; the orthographic projection of the working part on the top surface of the piezoelectric transducer is located in the top surface of the piezoelectric transducer right above the bottom electrode, and the orthographic projection of the connecting part on the top surface of the piezoelectric transducer is located in the top surface of the piezoelectric transducer right above the groove. By controlling the size and the relative position of the surface electrode and the bottom electrode, a welding area and a working area are distinguished, the problem that welding is not firm due to the fact that the width of the surface electrode is too narrow is solved, and the contradiction between diffraction efficiency and driving power under the condition is solved.

This invention discloses a high-precision optical imprinting method for fabricating sinusoidal cycloidal diffraction waveplates. By using a sinusoidal cycloidal diffraction waveplate with at least two layers of twisted structures as a polarization conversion diffraction waveplate, the precision of optical fabrication is improved, achieving optical imprinting of sinusoidal cycloidal periodic structures on the order of hundreds of nanometers. This method solves the problems of slow fabrication speed, poor resistance to environmental interference, and high cost and difficulty in further scaling up the exposure system, which limit mass production of sinusoidal cycloidal diffraction waveplates based on polarization holographic exposure systems.

The invention discloses a holographic polymer dispersed liquid crystal grating, which is obtained by carrying out holographic recording treatment on a mixture comprising liquid crystal and polymer, and comprises the following components in percentage by mass: 20 to 60 percent of liquid crystal and 40 to 80 percent of polymer, wherein the liquid crystal comprises a first liquid crystal compound which has a chiral structure and cannot be polymerized; the polymer comprises a photopolymerization compound and a photoinitiator composition, the photoinitiator composition comprises an initiator and a photosensitizer, and the initiator can initiate a polymer reaction under illumination. A chiral structure is introduced into non-polymerizable liquid crystal molecules, so that traditional liquid crystal molecules can be spirally arranged, the diffraction efficiency on S light is improved, and the high diffraction efficiency on the S light and P light is achieved at the same time. The invention further discloses a preparation method of the holographic polymer dispersed liquid crystal grating. The holographic polymer dispersed liquid crystal grating which has high diffraction efficiency on S light and P light at the same time can be prepared.

The utility model is suitable for the technical field of optics, and provides an optical machine and an enhanced display device.The optical machine comprises a light source assembly, a polarization body holographic grating, a first prism and a modulation chip, the light source assembly is used for providing first polarized light, and the polarization body holographic grating is used for diffracting the first polarized light and obtaining second polarized light deflected relative to the first polarized light; the first prism is provided with a first surface, a second surface and a third surface which are arranged at included angles, the first surface is used for receiving second polarized light, and the modulation chip is used for receiving the second polarized light emitted from the second surface and modulating the second polarized light to obtain third polarized light; the third polarized light is reflected by the first surface in the first prism and is emitted from the third surface. The polarizer holographic grating is combined with the triangular prism type first prism, a cube prism does not need to be used, and the size can be reduced; the ray machine is in a nearly long-strip-shaped state and is matched with an enhanced display device such as AR glasses in form; the diffraction efficiency is high, and the luminous efficiency of the optical machine is high.

The invention discloses a short-wave infrared InP-based photonic crystal surface emitting laser, and relates to the technical field of lasers. The laser comprises an n-type InP substrate, an n-type coating layer, a multi-quantum well layer, an electron blocking layer, a photonic crystal layer, a p-type coating layer and a metal distributed Bragg reflection layer which are sequentially arranged in the stacking direction. The photonic crystal layer is formed by periodically arranging a plurality of tri-lattice units, and a surrounding distributed Bragg reflection structure is arranged around the photonic crystal layer; at least two lattice points in the tri-lattice unit have lateral and longitudinal offsets with respect to another lattice point. Planar light leakage is suppressed through the peripheral distributed Bragg reflection structure, and in combination with active regulation and control of tri-lattice micro-offset on planar coupling and vertical radiation proportion, and through the synergistic effect of the planar coupling and the vertical radiation proportion, the simulation result shows that the slope efficiency is improved to 0.18 W / A and the vertical radiation loss proportion is improved to 45% while low threshold gain (26cm <-1 >) is kept, and the performance of the device is improved. Unification of low threshold and high efficiency is achieved, and the method is suitable for the fields of optical communication, laser radar and the like.

The invention provides a naked eye 3D head-up display system and method and a vehicle, and the system comprises an eye movement tracking unit which is used for obtaining a real-time eye image of a driver, and outputting the coordinate of a current fixation point; the processor is in communication connection with the eye movement tracking unit and is used for dynamically rendering display images of a plurality of screen display areas in a display area according to the coordinates of the current fixation point and fusing rendering results to form an output image with non-uniform resolution; and the optical engine is in communication connection with the processor and is used for performing light field reconstruction modulation on the display light corresponding to the output image to generate a three-dimensional image light field and guiding the three-dimensional image light field to a predetermined eye box area.

This invention relates to the field of materials technology, specifically to a polymer grating composition. The polymer grating composition comprises an initiator system, a non-reactive solvent system, and a high-refractive-index polymer monomer system; the initiator system includes a photosensitizer and an initiator; the high-refractive-index polymer monomer system includes low-viscosity monofunctional monomers, multifunctional monomers, and high-refractive-index polymer monomers; by mass percentage, the photosensitizer accounts for 0.1%-1%, the initiator accounts for 0.01%-2%, the non-reactive solvent system accounts for 10%-50%, the low-viscosity monofunctional monomer accounts for 0%-30%, the multifunctional monomer accounts for 10%-40%, and the high-refractive-index polymer monomer accounts for 10%-60%. The polymer grating composition of this invention increases the transmittance of the grating; the polymer grating composition of this invention is a high-efficiency composition, exhibiting high diffraction efficiency for both S-rays and P-rays; the polymer grating composition of this invention reduces the light scattering loss of the grating.