658 results about "Diffraction grating" patented technology

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.

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.

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.

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.

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.

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.

An aberration regulation method of a reflective double-beam interference exposure system, comprising: constructing a reflective double-beam interference exposure system, dividing a light beam output by a laser into two double beams with the same intensity, and forming an interference exposure field; constructing an aberration regulation system, testing and recording the aberration of the double-beam light path by using a spherical interferometer, and regulating the wavefront of any light beam in the double beam by using a deformable mirror, so that the aberration of the light beam matches the aberration of the other light beam, and the regulation of the aberration of the interference exposure field is completed. The present application solves the problems of precise assembly and adjustment, wavefront aberration control and the like of the reflective double-beam interference exposure system based on a large-aperture off-axis parabolic mirror, and provides a new solution for the preparation of a meter-level large-aperture, low-aberration diffraction grating.

Techniques are described for enhanced eye tracking for display systems, such as augmented or virtual reality display systems. The display systems may include a light source configured to output light, a moveable diffractive grating configured to reflect light from the light source, the reflected light forming a scan pattern on the eye of the user, and light detectors to detect light reflected from the eye. The orientation of the diffractive grating can be moved such that the light reflected from the diffractive grating is scanned across the eye according to the scan pattern. Light intensity pattern(s) are obtained via the light detectors, with a light intensity pattern representing a light detector signal obtained by detecting light reflected by the eye as the light is scanned across the eye. One or more physiological characteristics and / or a rotation speed of the eye are determined based on detected light intensity pattern(s).

The invention discloses a displacement measurement method and system based on orbital angular momentum light beam conjugate interference, and the method comprises the steps: enabling linearly polarized light emitted by a laser to pass through an optical attenuator, a light beam expander, a quarter-wave plate and a vortex wave plate to form a light beam with orbital angular momentum, and enabling the light beam to pass through a beam splitter to be divided into a reference light beam and a measurement light beam. A measurement light beam is vertically incident on a reflection grating, and the mth-order diffraction light is incident on a first cube-corner prism and is reflected back to a diffraction grating to be subjected to secondary diffraction. And after the reference beam passes through the second cube-corner prism, the topological charge symbol of the reference beam is changed by the Dove prism. The reference light beam and the measurement light beam generate conjugate interference at the beam splitter prism, a petal-shaped interference pattern collected by the CCD is demodulated, and in-plane and out-of-plane two-dimensional displacement of the grating is calculated. The system has the characteristics of simple and compact structure, strong anti-interference capability, high precision and the like, and can be widely applied to the fields of high-end equipment manufacturing, semiconductor industry, precision metering and the like.

An optical displacement sensor comprises a reflective surface and one or more diffraction gratings which, together with the reflective surface, each define a respective interferometric arrangement. The reflective surface is moveable relative to the diffraction grating(s) or vice versa. Light from a light source propagates via the interferometric arrangement(s) to produce an interference pattern at a respective set of photo detectors. Each interference pattern depends on the separation between the reflective surface and the respective grating. A collimating optical arrangement at least partially collimates the light between the light source and the diffraction grating(s). For the or each interferometric arrangement, when the reflective surface or the diffraction grating is in a zero-displacement position, the optical path length L of the light propagating between the diffraction grating and the reflective surface satisfies the relationship:L=Tz⁢n2,to within 20% ofTz2, where n is an integer; where Tz is the Talbot length, defined by:Tz=λ1-1-λ2p2,where λ is the wavelength of the light, and where p is the grating period of the respective diffraction grating.

An ophthalmic multifocal lens is presented, configured to provide distance vision and at least one other usable visual acuity. The lens comprises a translucent lens body having an optical axis and a refractive baseline, the refractive baseline extending to at least a portion of the lens body, and a diffraction grating configured to act as an optical splitter, extending concentrically in the radial direction and superimposed on at least a portion of the refractive baseline. The diffraction grating configured to act as an optical splitter is further configured to be continuous within at least a central 3 mm aperture, wherein the distance vision is provided by the -1st order diffraction, and the near vision is provided by the 2nd order diffraction.

The invention provides a wavelength calibration method, a calibration sample, and a program product. The wavelength calibration method is a wavelength calibration method for a multicolor spectrometer provided with a diffraction grating and a detector at which light dispersed by the diffraction grating is imaged. The wavelength calibration method includes the steps of: providing light containing a known clear spectrum to a multicolor spectrometer, and acquiring a first measurement result output from a detector; a second measurement unit that supplies reflected light or transmitted light to the multicolor spectrometer, said reflected light or transmitted light being generated by irradiating a calibration sample having a gap provided therein with light, and acquires a second measurement result output from the detector; determining a wavelength table such that the position of the known clear spectrum in the first measurement result matches the wavelength of the known clear spectrum; and repeating the update of the wavelength table so as to minimize an error calculated on the basis of the second measurement result and the wavelength table.

An optical component (1) comprises a diffraction grating and a microlens array that are hexagonal and angularly offset from each other by 10° to 50°. Such an optical component is particularly well-suited for use in a wavefront analyzer. The wavefront analyzer can alternatively have two configurations, in which the distance between the optical component and an image sensor is close to f / 2 or 3·f / 2, where f is the focal length of the microlenses (11). Such a wavefront analyzer can be compact, easy to use, and compatible with a wide range of wavelength values ​​for the electromagnetic radiation to be analyzed. (Shorthand figure: Figure 1)

A high-power multiplexer / demultiplexer ("mux / demux") and a three-dimensional ("3D") printed phase mask are provided for hollow-core optical fiber applications. The high-power mux / demux includes hollow core optical fiber interfaces configured to couple with free-space optical fiber cables, a diffraction grating, a 3D printed phase mask, and a set of lenses. The diffraction grating is configured, based on different wavelengths, either to at least diffract each optical signal of a plurality of optical signals having different wavelengths into two or more optical signals or to at least diffract a single optical signal having multiple wavelengths into a plurality of optical signals. The phase mask includes reflective features configured to reflect optical signals at different optical path lengths to provide reflected optical signals with different phases. The set of lenses is configured to collimate optical signals onto or from the diffraction grating or to focus optical signals onto or from the phase mask.

Plasma etching processes for forming patterns in high refractive index glass substrates, such as for use as waveguides, are provided herein. The substrates may be formed of glass having a refractive index of greater than or equal to about 1.65 and having less than about 50 wt % SiO2. The plasma etching processes may include both chemical and physical etching components. In some embodiments, the plasma etching processes can include forming a patterned mask layer on at least a portion of the high refractive index glass substrate and exposing the mask layer and high refractive index glass substrate to a plasma to remove high refractive index glass from the exposed portions of the substrate. Any remaining mask layer is subsequently removed from the high refractive index glass substrate. The removal of the glass forms a desired patterned structure, such as a diffractive grating, in the high refractive index glass substrate.

A wavelength beam combining device includes: a plurality of laser light sources configured to emit a plurality of laser beams in a first direction and having mutually different peak wavelengths and central axes arranged in a second direction intersecting the first direction; a first diffraction grating disposed at a position where the plurality of laser beams are received, the first diffraction grating being configured to diffract the plurality of laser beams in different directions according to wavelengths of the laser beams to cause the diffracted laser beams to enter the second diffraction grating; a second diffraction grating configured to diffract the plurality of laser beams diffracted by the first diffraction grating to form a wavelength-combined beam, and to direct the wavelength-combined beam in the first direction; and an optical coupling unit configured to couple the wavelength-combined beam to an optical transmission fiber and to be movable in the second direction.

A light field imaging device and method are provided. The device can include a diffraction grating assembly receiving a wavefront from a scene and including one or more diffraction gratings, each having a grating period along a grating axis and diffracting the wavefront to generate a diffracted wavefront. The device can also include a pixel array disposed under the diffraction grating assembly and detecting the diffracted wavefront in a near-field diffraction regime to provide light field image data about the scene. The pixel array has a pixel pitch along the grating axis that is smaller than the grating period. The device can further include a color filter array disposed over the pixel array to spatio-chromatically sample the diffracted wavefront prior to detection by the pixel array. The device and method can be implemented in backside-illuminated sensor architectures. Diffraction grating assemblies for use in the device and method are also disclosed.