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125results about How to "High diffraction efficiency" patented technology

Holographic waveguide display device

The invention discloses a holographic waveguide display device and belongs to the technical field of wearable display. The holographic waveguide display device comprises a micro displayer, a collimating lens, a diaphragm, a waveguide, an inlet coupling diffraction optical element and an outlet coupling diffraction optical element. The inlet coupling diffraction optical element comprises a reflection body holographic grating and a sub-wavelength one-dimensional metal nanometer grating. One side of the reflection body holographic grating is closely connected to the waveguide, and the sub-wavelength one-dimensional metal nanometer grating is arranged on the surface of the other side of the reflection body holographic grating. Photons penetrating through the reflection body holographic grating can be coupled into a surface plasma mode through the sub-wavelength one-dimensional metal nanometer grating, and thus the photons can enter the reflection body holographic grating again to be diffracted and enter the waveguide. Compared with the prior art, by means of the holographic waveguide display device, the diffraction efficiency of TM light can be improved on the premise of ensuring the high diffraction efficiency of the TE light, so that the total light energy utilization rate of the holographic waveguide display device is increased, and meanwhile stray light in transmission is effectively suppressed.
Owner:SOUTHEAST UNIV

Method and system for combining multiple laser beams using transmission holographic methodologies

The Holographic Beam Combiner, (HBC), is used to combine the output from many lasers into a single-aperture, diffraction-limited beam. The HBC is based on the storage of multiple holographic gratings in the same spatial location. By using a photopolymer material such as quinone-doped polymethyl methacrylate (PMMA) that uses a novel principle of “polymer with diffusion amplification” (PDA), it is possible to combine a large number (N) of diode lasers, with an output intensity and brightness 0.9 N times as much as those of the combined outputs of individual N lasers. The HBC will be a small, inexpensive to manufacture, and lightweight optical element. The basic idea of the HBC is to construct multiple holograms onto a recording material, with each hologram using a reference beam incident at a different angle, but keeping the object beam at a fixed position. When illuminated by a single read beam at an angle matching one of the reference beams, a diffracted beam is produced in the fixed direction of the object beam. When multiple read beams, matching the multiple reference beams are used simultaneously, all the beams can be made to diffract in the same direction, under certain conditions that depend on the degree of mutual coherence between the input beams.
Owner:SHAHRIAR SELIMM

Holographic optical waveguide and holographic optical waveguide display device

InactiveCN105487170ASolving Off-Axis Transmission IssuesSolve the problems of large thickness, uncompact structure and large volumeOptical light guidesLiquid-crystal displayDisplay device
The invention discloses a holographic optical waveguide, and belongs to the technical field of augmented reality and virtual reality. The holographic optical waveguide comprises a planar optical waveguide, and an optical coupling in end and an optical coupling out end which are respectively arranged at the two ends of the planar optical waveguide. The optical coupling in end reflects received light rays so that the reflected light rays are enabled to meet the total reflection conditions to be transmitted to the optical coupling out end through multiple times of total reflection between the two reflecting surfaces of the planar optical waveguide. The received light rays are diffractively emergent out of the optical coupling out end. The optical coupling out end is a holographic grating. The holographic grating is a polarization holographic liquid crystal grating comprising a transparent substrate, a light orientation layer and a liquid crystal layer which are arranged in turn, wherein polarization holographic patterns having periodic structures are recorded on the light orientation layer. The invention also discloses a holographic optical waveguide display device. The polarization holographic liquid crystal grating is used as the optical coupling out end of the holographic optical waveguide so that 100% of diffraction efficiency can be achieved theoretically, and zero order waves can be suppressed and conjugate images can be eliminated.
Owner:SOUTHEAST UNIV

Method for manufacturing triangular groove echelon gratings with 90-degree vertex angles

ActiveCN103901520AMake anyMeet the conditions for perfect sparkleDiffraction gratingsPhotomechanical exposure apparatusBroadbandWave band
The invention provides a method for manufacturing triangular groove echelon gratings with 90-degree vertex angles. Each triangular groove echelon grating is composed of a silicon grating structure (1), photoresist (3) and a metal film (4). A manufactured grating groove is a triangle with the vertex angle being 90 degrees, so that the diffraction efficiency higher than that of an echelon grating with the vertex angle being not 90 degrees can be achieved. Each grating structure is produced in an obliquely-cut monocrystalline wafer, the shining angles of the gratings are determined by an obliquely-cut angle for cutting each silicon wafer, and gratings with any blazing angles can be manufactured; according to the 90-degree vertex angles, grooves of silicon gratings with the vertex angles being not 90 degrees are filled with photoresist, then photoetching is conducted again, and the original silicon gratings with the vertex angles being not 90 degrees are converted into the triangular groove gratings with the vertex angles being 90 degrees. According to the manufactured grating structure, the shining face of each grating is a smooth monocrystal silicon <111> grate plane, scattering can be effectively lowered, and the diffraction efficiency of each grating is improved. The purpose that all the gratings have high diffraction efficiency on a broadband is achieved according to the fact that using wave bands can choose to be coated with various different reflecting film layers on the surfaces of the gratings.
Owner:UNIV OF SCI & TECH OF CHINA

Super-surface color vector complex amplitude holographic element

ActiveCN109709784AHigh diffraction efficiencySimultaneous and independent control of the amplitudeInstrumentsIn planeSuper structure
The invention discloses a super-surface color vector complex amplitude holographic element, which comprises a bimetallic nanorod unit structure with adjustable in-plane rotation angles and in-plane displacement, wherein an aluminum-silicon dioxide-aluminum super-structure grating structure generates a polarization-selective type diffraction efficiency enhancement effect in a visible light range; asum of in-plane displacement of two metal nanorods in the unit structure and diffraction phase information are in a linear modulation relationship, a difference between the rotation angles of the twometal nanorods and a diffraction light amplitude are in a sinusoidal modulation relationship, and a sum of the rotation angles of the two metal nanorods and a diffraction light polarization directionare in a linear modulation relationship; and a color holographic method is implemented on diffraction level by utilizing the phase displacement based on inherent dispersion of the super-structure grating. The super-surface color vector complex amplitude holographic element disclosed by the invention has the advantages of low requirements for preparation control precision, simple structure, high degree of control freedom and the like, and has powerful functions of simultaneously controlling four parameters of light wave phase, polarization, amplitude and frequency.
Owner:JINAN UNIVERSITY

Electronic-control high-efficiency holographic grating made of polymer dispersed liquid crystal materials doped with nano metal and preparation method thereof

The invention discloses an electronic-control high-efficiency holographic grating made of polymer dispersed liquid crystal materials doped with nano metal and a preparation method of the holographic grating. The preparation method comprises the following steps, uniformly mixing and heating polymer dispersed liquid crystal materials containing nano metal particle materials by an ultrasonic emulsification instrument under the light shading condition, standing for 24-48h in a dark room, then injecting the polymer dispersed liquid crystal materials into a liquid crystal box, and then arranging the packaged liquid crystal box at a holographic light field of a helium-cadmium laser for exposure to finally obtain the electronically-controlled high-efficiency holographic grating made of polymer dispersed liquid crystal materials doped with nano metal. In the steps, the polymer dispersed liquid crystal materials comprise the following components by weight: 0.1-0.2% of photoinitiator, 0.3-0.5% of coordinated initiator, 9-11% of cross linking agent, 9-10% of surface active agent, 0.1-0.2% of nano metal particles, 40-50% of polymers and 30-40% of nematic liquid crystal. According to the electronic-control high-efficiency holographic grating made of polymer dispersed liquid crystal materials doped with nano metal, the diffraction efficiency reaches up to 85%-95%, the response speed is less than 1ms, and the electro-optic properties are improved remarkably.
Owner:UNIV OF SHANGHAI FOR SCI & TECH

High-power laser diffraction type spatial filter

InactiveCN101738739AImproved angular spectral selectivityIncreased bandwidthOptical elementsLaser burnGrating
The invention discloses a high-power laser diffraction type spatial filter. The left side of the high-power laser diffraction type spatial filter is provided with an interstage isolation filter of which the central axis is a vertical line BC, the middle of the high-power laser diffraction type spatial filter is provided with a group of gain medium of which the central axis is a transverse line CD, the right side of the high-power laser diffraction type spatial filter is provided with a multi-pass cavity filter of which the central axis is a vertical line DE, the central axis of the entire device forms a BCDEF broken line, one optical grating which enables light beams to be deflected at 90 degrees is respectively arranged at a point B, a point C, a point D and a point E, the optical gratings are separate type volume Bragg optical gratings or double-piece integrated type optical gratings, and one reflecting mirror is arranged at a point F. The invention uses an optical grating double-pass spatial filter component which does not have a lens and a pinhole and has compact appearance to replace a pinhole filter in a multi-pass amplifier, can realize the wider width of a diffraction frequency band and can meet the requirement of short-pulse and ultrashort-pulse spatial filtering; the borne laser power is higher, and the requirement of high-power laser spatial filtering can be met, thereby eliminating the probability that laser burns out the filter component because of no lens and no pinhole in the device.
Owner:谭吉春

Three-dimensional microstructure inscribing system and method based on continuous laser

The invention discloses a three-dimensional microstructure inscribing system and method based on continuous laser. The three-dimensional microstructure inscribing system based on continuous laser comprises a continuous laser device, an acoustic-optical modulator, an objective lens, a photosensitive material and a three-dimensional nano displacement platform, wherein the continuous laser device is used for emitting laser light; the acoustic-optical modulator is used for adjusting the power of the laser light; the objective lens is used for focusing the laser light with the power being adjusted through the acoustic-optical modulator, so that a focused light beam is obtained, and the power density of the focused light beam is larger than the threshold power density obtained through two-photon absorption; the photosensitive material is subjected to two-photon polymerization under the effect of the focused light beam so as to be solidified, and thus two-photon polymerization direct-writing is achieved; and the three-dimensional nano displacement platform is used for carrying the photosensitive material and controlling the photosensitive material to move in the three-dimensional direction, and thus three-dimensional microstructure inscribing of the photosensitive material is achieved through layer-by-layer two-photon polymerization direct-writing of the photosensitive material. According to the three-dimensional microstructure inscribing system and method based on continuous laser, the low-cost laser continuous laser device is used as an inscribing light source, the power of the inscribing light source is adjusted through the acoustic-optical modulator, three-dimensional microstructure inscribing of the continuous laser device is achieved, and cost is reduced.
Owner:HUAZHONG UNIV OF SCI & TECH

Annular radiation type blazed grating

The invention relates to an annular radiation type blazed grating which comprises an annular grating baseplate, blazed grating teeth (3) and diffraction surfaces (4), wherein the blazed grating teeth (3) are etched on the annular grating baseplate, and the diffraction surfaces (4) are positioned at one side of notched ridge lines (2) of the blazed grating teeth. The annular radiation type blazed grating is characterized in that the blazed grating teeth (3) are periodically arranged on the circumference of the annular grating baseplate, each blazed grating tooth (3) is in a radiation type, the projection of the upper surface of the annular grating baseplate is fan-shaped, and the bottommost parts of scale marks on the blazed grating teeth (3) are positioned on a plane (6); the diffraction surfaces (4) of the blazed grating teeth (3) are larger planes on one side of the notched ridge lines (2); and a plane formed from straight lines (11) and (12) perpendicular to the notched ridge lines (2) of the blazed grating teeth and the plane (6) intersect at a straight line (13), the straight line (13) and each diffraction surface (4) form a blaze angle (14), and the blaze angle (14) is unchanged for each blazed grating tooth. Compared with the prior art, the annular radiation type blazed grating has the beam deflection performance which other round or annular blazed gratings do not have, and the annular radiation type blazed grating is convenient to manufacture and has the characteristic of high diffraction effect. On the aspect of economic benefit, the annular radiation type blazed grating can be widely applied to occasions needing beam deflection, spectral analysis and the like, particularly to the deflection of revolving beams.
Owner:TIANJIN UNIV
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