786 results about "Diffraction grating" patented technology

Head-mounted displays with waveguides comprising superimposed diffractive gratings and methods for fabricating said waveguides are described herein. In an embodiment, a head-mounted display comprises an optical element and an image source that provides an image beam to an optical element. The optical element comprises two gratings superimposed over each other, at least one of which comprising a buried diffractive grating. The buried diffractive grating comprises a high-refractive index material interspersed with a low-refractive index material or non-solid pockets, such as gas, air or vacuum. Light diffracted by a first of the two gratings is further diffracted by a second of the two gratings without interacting with a surface of the optical element between diffractions.

The invention relates to an all-fiber sub-hundred femtosecond laser based on an SESAM. The all-fiber sub-hundred femtosecond laser comprises the SESAM, a wavelength division multiplexer, a pumping source, a pumping protector, a gain fiber, a chirp fiber bragg grating, an isolator, a reflector, a compression unit and an autocorrelator. According to the invention, the chirp fiber bragg grating with the dispersion amount of 0.115 ps / nm is adopted to compensate positive dispersion in the cavity, so that mode-locked pulse with the spectral width of 23nm is realized. A transmission-type diffraction grating pair is adopted, the pulse width is compressed to 88fs, and the maximum spectral width 27nm is obtained under the dispersion of 0.00087 ps2 in a near-zero cavity. The condition that the optimal spectral bandwidth of the optimal seed source pulse based on the optical fiber chirped pulse amplification laser should be larger than 15 nm is met, and the compression pulse distortion of the amplifier is reduced. By adopting the linear cavity, the SESAM is adhered to the surface of the single-mode optical fiber patch cord for starting mode locking, so that an all-optical-fiber structure of the system is realized, and the single-mode optical fiber patch cord is suitable for industrial integrated application.

The invention belongs to the technical field of laser, and discloses a grating multiplexing spectrum synthesis system, which comprises a beamlet dense array, a diffraction grating and a turn-back mirror, each beamlet emitted by the beamlet dense array is diffracted by the diffraction grating and then is emitted in the form of convergent light, and the light is reflected twice by the turn-back mirror to form a light beam; each laser sub-beam is incident on the diffraction grating again along the opposite direction parallel to the original light, the sub-beams converge into one point on the diffraction grating by adjusting the distance between the turn-back mirror and the diffraction grating, and at the moment, the incident angle of each sub-beam is equal to the diffraction angle diffracted from the diffraction grating for the first time; and the diffraction angles of the sub-beams subjected to the second diffraction on the diffraction grating are equal and equal to the incident angle of the sub-beams subjected to the first diffraction, that is, the synthesized light beam is emitted along the direction parallel to and opposite to the direction of the light beam emitted from the sub-beam dense array. The invention provides a spectrum synthesis system which is simple in structure, easy in engineering implementation and compact in volume.

The invention provides a grating assembly and a manufacturing method of the grating assembly. The grating assembly comprises a substrate; the number of the optical cement auxiliary structures is multiple, and the multiple optical cement auxiliary structures are formed on the surface of one side of the substrate at intervals through nanoimprint; the functional layer covers the sides, away from the substrate, of the optical cement auxiliary structures in a shape follow-up mode so that the side faces and the top faces of the optical cement auxiliary structures can be wrapped by the functional layer, and gaps are reserved in the sides, away from the substrate, of the functional layer; the optical adhesive layer is arranged on the side, away from the substrate, of the optical adhesive auxiliary structure, and the projection of the optical adhesive layer on the substrate completely covers the optical adhesive auxiliary structure and the functional layer; the functional layer is a deposition layer, the grating assembly further comprises a plurality of diffraction gratings, and the diffraction gratings are filled in the gaps. The problem that the diffraction efficiency of a grating assembly in the prior art is difficult to improve is solved.

The invention discloses a grating displacement encoder grating spacing error in-situ detection and self-compensation method, and belongs to the technical field of optical measurement, and the method comprises the steps: generating elliptically polarized light, modulating the elliptically polarized light into S polarized light, reflecting the S polarized light through a polarization beam splitter, converting the S polarized light into circularly polarized light through a quarter-wave plate, and enabling the circularly polarized light to enter a diffraction grating ruler; the diffraction grating ruler diffracts incident light to form first-order diffraction light and second-order diffraction light; processing and interference detection are carried out on the first-order diffraction light, and precise displacement conversion is carried out in combination with the Doppler effect of grating displacement; constructing an auto-collimation angle detection sensing module by using second-order diffraction light, and converting the distance manufacturing deviation of diffraction gratings by detecting the tiny change of a diffraction angle; and compensating the displacement measurement error of the grating encoder in real time according to the real-time detection result of the grating spacing manufacturing deviation. According to the invention, the off-line detection time and cost of the grating are greatly saved.

The utility model discloses a novel wavelength selection switch, which relates to the technical field of all-optical communication and comprises an optical fiber collimation array, a Fourier lens, a 4f imaging system, a diffraction grating, an LCOS (Liquid Crystal On Silicon) device and an MEMS (Micro Electro Mechanical System) device which are sequentially arranged along the direction of an optical path. According to the utility model, by utilizing the fine modulation and deflection characteristics of the LCOS device to the light beam and combining the wide-angle scanning characteristic of the MEMS device, the wavelength selective switch capable of greatly increasing the number of output ports is provided, the reconfigurable optical add-drop multiplexing function is realized, the miniaturization and standardization of the WSS module are realized, and the optical communication technology is high in efficiency and wide in universality.

A system and method are provided for determining a location of a laser using a diffraction grating. The system includes a lens that projects diffraction patterns from the diffraction grating as an image of diffraction peaks onto a plane. Optical sensors then sense the diffraction peaks. A processor connected to the optical sensors applies a laser position determination method to determine the laser location. In the method, the processor obtains the diffraction peak measurements from the optical sensors and applies a transform to arrange the diffraction peaks into a grid of regularly spaced peaks. The processor then applies convolution kernels to analyze the grid of regularized peaks to to determine a position of a zeroth order diffraction central peak that is used to calculate the angle of incidence of the axis of the laser beam to determine the laser position.

A vertical cavity light-emitting element includes a gallium-nitride-based semiconductor substrate, a first multilayer reflector, a semiconductor structure layer, a second multilayer reflector, and a current confinement structure. The first multilayer reflector is formed on the substrate. The second multilayer reflector is formed on the semiconductor structure layer and constitutes a resonator with the first multilayer reflector. The current confinement structure is formed between the first multilayer reflector and the second multilayer reflector to concentrate a current in one region of the active layer. A diffraction grating is formed in a region overlapping with the one region when viewed from a normal direction of an upper surface of the substrate. The diffraction grating is made of a plurality of slit structures parallel to each other.

An electronic device may include a waveguide that directs light to an eye box. The waveguide may include a diffractive grating structure. A projector may generate image light coupled into the waveguide by a first input coupler. A light source may generate supplemental light coupled into the waveguide by a second input coupler. The diffractive grating structure may couple the image light out of the waveguide within a central region of the field of view (FOV) of an eye box and may couple the supplemental light out of the waveguide at a location within a peripheral region of the FOV. The location may be outside of the central region by at least 10 degrees. A gaze tracking sensor may estimate a user's gaze direction at the eye box. A processor may wake or power down the projector responsive to the gaze direction overlapping the location for a predetermined time period.

The invention provides an anti-counterfeit label film coating tension control method and system, and relates to the technical field of film coating tension control. The method comprises the following steps: acquiring surface image data of a substrate film; identifying and acquiring real-time coordinates of the feature points; calculating the local strain of the substrate film according to the real-time coordinates of the feature points; calculating to obtain a strain deviation; calculating the time required by the film section corresponding to the strain deviation to reach the film coating station as the adjustment time; calculating a tension compensation amount according to the strain deviation; and within the adjusting time, the tension control unit adjusts the tension applied to the substrate film according to the tension compensation amount. According to the method, through accurate local strain measurement and prospective tension adjustment, it is ensured that each section of film is kept in an ideal strain state at the moment of film coating, so that the integrity and functional effectiveness of optical microstructures such as diffraction gratings are thoroughly protected, and the technical problems in anti-counterfeit label film coating production are effectively solved.

The invention relates to a hundred-milliwatt high-power high-repetition-frequency terahertz strong source generating device at room temperature, belongs to the technical field of nonlinear optical frequency conversion, and solves the problems that the terahertz conversion rate is low and additional cooling equipment is needed in the prior art. The beam expanding lens group is used for carrying out light spot beam expanding on the femtosecond pumping laser until the diameter of a light spot is twice of the original diameter; the plane mirror group is used for guiding the pump laser after beam expansion; the first half-wave plate, the reflective diffraction grating, the gold reflector and the third ultrafast reflector are used for adjusting polarization and diffraction reflection; the 4-f telescope imaging lens group is used for reducing the spot diameter of the received pump laser and imaging the pump laser to the lithium niobate crystal; the lithium niobate crystal generates terahertz pulse radiation in the direction perpendicular to the wavefront; the terahertz collection module receives and focuses the terahertz pulse radiation; and the measuring device is used for receiving the focused terahertz pulse radiation for measurement.

A light-receiving device includes a light-receiving element in which a plurality of light-receiving portions are provided; and a glass cover that has a first surface and a second surface opposite to the first surface and that is fixed above the light-receiving element such that the second surface faces the light-receiving element. The glass cover includes a plurality of diffraction gratings provided in at least one of the first surface and an inside of the glass cover. Each of the plurality of diffraction gratings is configured to concentrate laser light for distance measurement on each of the plurality of light-receiving portions, the laser light for distance measurement incident on the first surface of the glass cover.

A system and method are provided for characterizing a laser using a diffraction grating. The system includes a lens that projects diffraction patterns from the diffraction grating as an image of diffraction peaks onto a plane. Optical sensors then sense the diffraction peaks. A processor connected to the optical sensors applies the laser characterization method to determine the laser wavelength, irradiance and angle of incidence. In the method, the processor obtains the diffraction peak measurements from the optical sensors and applies a transform to arrange the diffraction peaks into a grid of regularly spaced peaks. The processor then applies convolution kernels to analyze the grid of regularized peaks to determine a wavelength, irradiance and angle of incidence of the laser.

An optical transmitter includes a distributed feedback (DFB) laser having an active region formed as a multiple quantum well (MQW) and a diffraction grating, an electro-absorption (EA) modulator having an absorption region formed as a MQW having a composition different from a composition of the DFB laser, a semiconductor amplifier (SOA) having an active region having a same composition as the composition of the DFB laser, a bent waveguide that rotates a light propagation direction, and a passive waveguide connected to the SOA and including a core having a band gap wavelength shorter than an oscillation wavelength of the DFB laser. A tapered region of the passive waveguide converts a width W1 of the passive waveguide connected to the SOA into a width W2 of a narrow waveguide region of the passive waveguide, and the passive waveguide is in contact with the end surface of the substrate.

The invention relates to the technical field of grating interferometry, in particular to a Littrow grating interferometry device and a use thereof. The device comprises: a two-frequency orthogonal polarization light source, a polarizing beam splitting prism, a reflection assembly, a detector, and a first diffraction grating and a second diffraction grating having identical parameters. The output light of the two-frequency orthogonal polarization light source is split by the polarizing beam splitting prism into horizontally polarizing measuring light which is transmitted and vertically polarizing measuring light which is reflected. The two beams of measuring light undergo diffraction twice between the first diffraction grating and the second diffraction grating, and finally the two beams of measuring light interfere with each other and are incident on the detector. Grating displacement is calculated according to the interference pattern. The invention achieves secondary diffraction under Littrow incidence, and improves the precision of displacement measurement.

Waveguide modification includes modifying waveguide combiners, output coupler, and pupil expander regions, which contain diffraction gratings, based on user and display characteristics during manufacturing. The diffraction grating is generally configured to combine received display light, representing an image for display, and directs the combined light to a location where the image can be comfortably viewed by the user. Because the desired location for the display can vary based on characteristics of the user, the diffraction grating is modified during manufacturing, such as by covering portions of the grating, to tailor the characteristics of the diffraction grating for a particular user or group of users.

The laser module includes a QCL element, a MEMS diffraction grating, a lens holder for holding a lens disposed between the QCL element and the MEMS diffraction grating, and a package. The package includes a bottom wall, a side wall erected on the bottom wall and formed in an annular shape so as to surround a region in which the QCL element is accommodated, and a top wall closing an opening of the side wall on a side opposite to a side where the bottom wall is disposed. The top wall faces the bottom wall in a direction orthogonal to the optical axis direction of the lens, and the distance between the top wall and a surface of the lens holder on a side where the top wall is disposed is smaller than a thickness of the lens holder along the optical axis direction of the lens.

Provided is an image display apparatus capable of detecting the amount of light of each wavelength of the ambient light transmitted through the image display panel with high accuracy in an image display apparatus including an image display panel and an ambient light sensor system. An image display apparatus includes an image display panel and an ambient light sensor system, in which the image display panel includes a transmission unit that allows ambient light to pass through in a display region. The ambient light sensor system includes a diffraction grating that diffracts light of each wavelength component at different angles according to a wavelength of the ambient light that has passed through the transmission unit, and a light detection unit that receives the light diffracted by the diffraction grating.

An optical arrangement (101) comprises a transparent waveguide (110) configured to guide light of a design wavelength therein, and an out-coupling arrangement (120) with a diffractive grating (130) configured to couple the light out of the waveguide. The diffractive grating (130) comprises a two—dimensional grating having a slanted configuration and comprising at least two grating layers (135, 136) with a refractive index difference between adjacent grating layers.

To provide a photosensitive composition capable of further improving diffraction characteristics.The present technology provides a photosensitive composition including: at least a compound represented by the following general formula (1); a binder resin; and a photoinitiator.In the general formula (1), X1 represents an oxygen atom, a nitrogen atom, a phosphorus atom, a caron atom, or a silicon atom.Y1 and Y2 each represent a benzene ring or a naphthalene ring, and both Y1 and Y2 do not represent benzene rings.R1 to R3 each represent a hydrogen or a substituent group represented by *—Z1(R4)d (* represents a bonding site).Z1 represents a single bond, a saturated hydrocarbon group having a valence of 2 or higher, or an unsaturated hydrocarbon group having a valence of 2 or higher, and the saturated hydrocarbon group or the unsaturated hydrocarbon group may have an ether bond and / or a thioether bond.R4 represents a hydrogen or a polymerizable substituent group.

The invention provides a multi-core optical fiber strain and temperature decoupling method and system for grating demodulation, electronic equipment and a storage medium, and relates to the technical field of optical fiber sensing, and the method comprises the steps: obtaining the lowest wavelength data of the spectrum of fiber cores at two sides of an air layer of a multi-core optical fiber, and recording the position data of a light spot formed by the secondary dispersion of a diffraction grating at the same time. The diffraction grating is used for secondary light splitting of the composite light, independent spectrum data are generated, and two-core coupling is blocked through an air layer. A double-task analysis network is constructed, strain wavelength offset is obtained through strain branches, and temperature wavelength correction is obtained through temperature branches. Network weight is adjusted in combination with related data to generate a strain demodulation value of temperature decoupling, the strain demodulation value is converted into a standardized signal to be transmitted to a monitoring system, an axial strain dynamic distribution diagram is reconstructed, a temperature compensation curve is synchronously displayed, multi-core optical fiber strain and temperature accurate decoupling can be achieved, strain information can be dynamically obtained, and the distribution and compensation state can be synchronously displayed.

Waveguide combiners with multiple image planes are described herein. In an example, an apparatus includes a first optical element configured to receive light, a substrate having an input surface and an output surface and configured to propagate the light received by the first optical element along a propagation path within the substrate, and a second optical element configured to output the light propagated along the propagation path. The input surface of the substrate is coupled to the first optical element. The second optical element includes a first diffraction grating coupled to the output surface and characterized by a first focal distance and a second diffraction grating coupled to the first diffraction grating in a stacked arrangement and characterized by a second focal distance.

The invention discloses a multi-level diffraction grating precision displacement sensor and a displacement measurement method, and relates to the field of displacement sensors. The grating precision displacement sensor comprises a laser, a half-wave plate, a first non-polarization splitting prism, a + / -2-level diffraction interference grating precision displacement sensor module and a + / -3-level diffraction interference grating precision displacement sensor module. And a final displacement measurement result is calculated after weighting by taking the noise levels of the + / -2-level diffraction interference grating precision displacement sensor module and the + / -3-level diffraction interference grating precision displacement sensor module as weights. The multi-level diffraction grating precision displacement sensor provided by the invention improves the utilization rate of effective light by using the polarization characteristic of light, reduces the interference of environmental stray light on measurement signals, and improves the accuracy and stability of the whole system.

A light source apparatus includes: a light source configured to output light; a reflection unit (spatial light modulator) having an input unit of a control signal and configured to be able to control distribution of angles at which incident light is reflected based on the control signal; and a diffraction grating configured to disperse the light output from the light source, cause the light to be incident on the spatial light modulator, and return at least a part of the light reflected by the spatial light modulator to the light source. An optical cavity is formed by the light source and the spatial light modulator, and a bandwidth of the light returned from the diffraction grating to the light source is controlled by controlling the distribution of angles of the light reflected by the spatial light modulator based on the control signal.

The invention provides a spectrum confocal three-dimensional shape measurement method and system based on an area light source, and belongs to the technical field of optical measurement, and the method comprises the steps: employing a Micro LED area light source capable of line-by-line driving to generate RGB three-color modulated isoenergetic white light, and after collimation and beam splitting of a beam splitter prism, the isoenergetic white light is converted into a light source; and the dispersion objective lens axially focuses light rays with different wavelengths at different height positions on the surface of a measured object. The reflected light is reflected to the array slit through the beam splitter prism and is split by the diffraction grating to form a spectral image containing space-wavelength two-dimensional information, and the surface height is analyzed by using a peak wavelength-height mapping relation. Full-field scanning is achieved by switching the area light sources line by line, and three-dimensional shape reconstruction can be completed without mechanical movement. The invention has the advantages of high light source brightness, high light source uniformity, uniform energy distribution of each wavelength, high scanning speed and high spatial resolution.

The invention belongs to the technical field of diffraction optical waveguides, and relates to an optical waveguide structure and a processing method thereof. The optical waveguide structure comprises a substrate and a first diffraction grating, the substrate is provided with a plurality of functional areas, at least one functional area is provided with the first diffraction grating, and the first diffraction grating comprises a plurality of first grating units which are sequentially arranged at intervals. The heights of the multiple first grating units are gradually increased or decreased in the interval direction. According to the optical waveguide structure, the light emitting performance of the optical waveguide structure can be improved, and the average light emitting efficiency and the light emitting uniformity of the optical waveguide structure are improved.

To improve image quality by suppressing a loss caused by Fresnel reflection. Provided is a light guide plate including at least an incidence diffraction grating that diffracts incident light into the light guide plate, a substrate that internally and totally reflects the light diffracted into the light guide plate by the incidence diffraction grating and guides the light, and a function part that transmits or reflects the incident light or performs both of the transmission and the reflection, wherein when the substrate has a refractive index of nb,a transmittance T0 of zeroth-order transmitted light of the function part substantially at the center of the field angle area for guiding light satisfies formula below:T⁢0>1-(nb-1)2 / (nb+1)2

Systems and methods of microscopy include and / or implement a laser configured to output a first beam and a second beam; a first optical system configured to receive the first beam, the first optical system comprising: a first beam splitter configured to split the first beam into a first component and a second component, a first photonic crystal fiber configured to modify a bandwidth of the first component, and a first pulse shaper configured to shape the first component in at least one of a spatial aspect or a temporal aspect, the first pulse shaper including a first diffraction grating, a first achromatic half-wave plate, a first lens, and a first two-dimensional spatial light modulator (SLM); and a second optical system configured to receive the second beam.

The laser module includes a housing with a bottom wall on which a mount member is placed, and accommodates a QCL element, a diffraction grating unit, a first lens holder, a second lens holder, and the mount member. The mount member includes a first mounting section for mounting the first lens holder, a second mounting section for mounting the QCL element and a temperature sensor, a third mounting section for mounting the second lens holder, and a fourth mounting section for mounting the diffraction grating unit. At least a second surface of the second mounting section facing the bottom wall is fixed to the bottom wall via a medium having a higher thermal conductivity than air and filled between the second surface and the bottom wall.

An eye tracking system for detecting position and movements of a user's eyes in a head-mounted display (HMD). The eye tracking system includes at least one eye tracking camera, an illumination source that emits infrared light towards the user's eyes, and diffraction gratings located at the eyepieces. The diffraction gratings redirect or reflect at least a portion of infrared light reflected off the user's eyes, while allowing visible light to pass. The cameras capture images of the user's eyes from the infrared light that is redirected or reflected by the diffraction gratings.