172 results about "Phase plate" patented technology

The present invention discloses an in-situ detection device and method for the surface shape of an optical-mechanical component, which belongs to the field of optical precision detection technology, and aims to solve the problem in the prior art that there is a lack of in-situ monitoring and detection of surface shape distortion during the adjustment process of an optical-mechanical component. The laser light generated by the laser in the device is incident on the optical-mechanical component to be measured after passing through a beam isolator, a beam splitter prism, and a collimator A in sequence, and is reflected. The reflected light of the optical-mechanical component to be measured is incident on the beam splitter prism after passing through the collimator A and is reflected. The reflected light of the beam splitter prism is incident on a CCD camera after passing through a perforated light screen, a collimator B, and a phase plate. The CCD camera is connected to a computer system, and the light spot diagram recorded by the CCD camera will be input into the computer system for in-situ detection of the surface shape. The method modulates the reflected light of the sample to be measured by a phase plate, and uses a phase reconstruction algorithm based on light field diffraction iteration to realize sample surface shape reconstruction. It has the advantages of high measurement accuracy, no need for a reference plane, and strong vibration resistance.

The invention relates to the technical field of multi-plane light conversion, in particular to a multi-dimensional demultiplexing and frequency mixing system based on an MPLC and an optimization design method of the multi-dimensional demultiplexing and frequency mixing system. The system comprises an input module used for inputting multimode signal light and local oscillation light; the MPLC module is used for realizing unitary transformation of light in any space, comprises N cascaded phase transformation areas and is integrated on the reflecting mirror or the transmitting mirror; the phase transformation regions are phase plates or metasurfaces, and at least one phase transformation region is a metasurface; and the output module is used for receiving the single-mode Gaussian light spots after demultiplexing and frequency mixing. According to the invention, different phases of different wavelengths and different polarization states are regulated and controlled through the metasurface; parallel demultiplexing of wavelengths, polarization and modes in multimode signals can be realized.

The invention discloses a projection photoetching machine alignment sensing system based on vortex light spatial modulation. Wherein the reflector is located between the silicon wafer alignment mark and the first lens, reflects a light beam which is emitted by the alignment light source and is parallel to the silicon wafer alignment mark, and generates a first reflection light beam which vertically irradiates a first grating or a second grating of the silicon wafer alignment mark; after the first reflection light beam is diffracted by the silicon wafer alignment mark, generated positive first-level diffraction light and negative first-level diffraction light are upwards transmitted to the second lens through the first lens; the detector receives convergent light beams which vertically penetrate through a first vortex phase plate and a second vortex phase plate which are distributed on two sides of a central optical axis of the alignment sensing system in an xz plane; or receiving a convergent light beam which vertically penetrates through a third vortex phase plate and a fourth vortex phase plate which are distributed on the two sides of the central optical axis of the alignment sensing system in the yz plane. The system provided by the invention can realize the position detection of the alignment mark of the sub-nanometer and deep sub-nanometer precision photoetching machine.

Laser absorption spectroscopy using multipass absorption based on multi-plane light conversion is a very sensitive chemical sensing technique to determine the molecular composition and concentration of a sample, especially a gas sample. To achieve a long optical path length while keeping the detector small, many trace gas sensors rely on multipass absorption cells in which the beam is reflected multiple times. The novel approach of the present invention consists in using multi-plane light conversion (MPLC) phase plates as reflectors in such multipass absorption cells.

The present invention discloses a wireless cross-domain acoustic communication system and method based on acoustic holography. The acoustic holographic device used for cross-domain acoustic communication consists of a single-layer acoustic holographic phase plate, an array transducer, and a camera vision module, wherein each array element of the array transducer has two states: on / off. After receiving the communication coding signal transmitted in the water, the transducer array elements at the corresponding positions can be sequentially selected and the dynamic regulation of the incident sound field can be realized. Then, the sound is transmitted to the water-air interface through the single-layer holographic phase plate and phase-modulated. Under the action of the acoustic radiation force, the interface will deform. The camera vision module is used to capture and parse and decode the deformation of the water surface, completing the wireless reception of information across the water-air interface. The present invention can directly transmit underwater information to the air. The equipment is simple and the relative position requirements of the transmitting and receiving devices are not strict. It is applicable to liquid environments of any temperature, salinity, and density.

Method and opto-electronic measuring device for measuring of an object's surface with a measuring rate of at least one thousand object points per second. Using a high-speed autofocus optical module comprising at least one variable focal length lens or reconfigurable optical phase plate having a response time of under 1 ms, situated in an emitting beam path, there is a real-time focus adaption of the measurement beam within a single object point measurement period.

The invention discloses a large-area phase pattern processing method and device, and belongs to the field of phase plate processing. The method comprises the following steps: dividing a phase pattern to be processed into a plurality of blocks; controlling a first displacement table to move a corresponding position of the substrate to a light processing position based on one selected block of the plurality of blocks; a second displacement table is controlled to move the substrate in the blocks based on the moving direction of the first displacement table, and light processing is carried out; selecting a next block of the plurality of blocks; and the steps are repeated until the machining of the multiple blocks is completed. According to the method, extremely-high-precision large-area pattern transfer can be achieved, the problem that it is difficult to balance the area and precision in a traditional machining technology is solved, the phase plate prepared through the method is large in area, high in fineness and high in stability, and different patterns can be flexibly adjusted and prepared according to actual needs.

The method and device for mapping the local irradiation flux of laser target shooting based on phase plate positioning belong to the field of laser target shooting experiments. The present invention aims to solve the problem that the flux data in the existing optical element damage test analysis only uses the average flux as the result, and cannot achieve the correspondence between the target surface beam flux and the damage point. The present invention includes a calibration step for obtaining an affine transformation matrix and a step for performing a laser target shooting experiment to obtain the local irradiation flux of the target material. A phase plate is inserted between the lens and the target material in the target shooting experiment optical path, an array of damage points is formed on the rear surface of the target material, and an affine transformation matrix is ​​constructed. The phase plate is removed and the laser target shooting experiment is performed using the original experimental optical path; the near-field image of the target shooting laser beam is mapped to the target material damage image according to the affine transformation matrix, and the near-field image of the target shooting laser beam and the target material damage image are superimposed to obtain the position of the phase mark point corresponding to the target material damage point; and then the local irradiation flux of the laser target shooting at the location of each damage point on the target material is obtained.

The invention provides an intelligent optical sensing system and method for imaging through an underwater turbid environment, and belongs to the field of underwater optical imaging. The problem of low underwater object recognition efficiency caused by difficulty in obtaining clear images in turbid water by existing equipment is solved; the system comprises an optical imaging module, an image acquisition module and computing equipment which are carried on diving equipment, computer programs of an image preprocessing module, a depth sensing module and a neural network denoising recognition module run on the computing equipment, and the optical imaging module generates a structured light field carrying an orbital angular momentum mode based on a spiral phase plate; the image acquisition module is used for acquiring reflection information of the target object irradiated by the vortex light; the image preprocessing module is used for enhancing the acquired image; the depth sensing module obtains the current water pressure through a pressure sensor, and the current water depth is inversely solved through the computing device; the neural network denoising recognition module carries out real-time recognition and denoising on the image; the method is applied to turbid underwater imaging.

A programmable 3D light beam shaping device based on the beamlet printing technology comprises a laser source, the laser source emits initial laser, the polarization state of the initial laser is adjusted through a rotatable half-wave plate, and then the initial laser is separated into an s component light beam and a p component light beam through a first polarization splitting prism, the p-component light beam enters a Dammann grating after being expanded, and a diffracted light beam containing a plurality of diffraction orders is generated; the diffracted light beam sequentially passes through a second polarization splitting prism, a quarter-wave plate and a first focusing element and is introduced into focal shift by a multi-stage phase plate array, and the spatial light modulator is used for adjusting the angle and position offset of subgroups of the light beam of the sub-beam array to generate a working light beam; the working light beam returns to the second polarization splitting prism through the original light path and enters the working area through the second focusing element, and a three-dimensional light field is generated; according to the device, the three-dimensional irradiance distribution in a machining area can be accurately controlled, so that multi-layer and depth-adjustable energy deposition is realized, and the machining quality, efficiency and consistency are remarkably improved.

The invention discloses a method for generating an enhanced image of a bright-field microscope, and the method comprises the steps: simulating an optical imaging model of optical Zernike phase contrast microscope imaging through a computer system based on the optical imaging principle of a conventional optical Zernike phase contrast microscope; extra hardware such as an annular diaphragm and an annular phase plate does not need to be added in an illumination light path and an imaging light path of the bright-field microscope, enhancement of the phase contrast of a bright-field digital microscopic image is achieved, energy loss of an illumination optical system is avoided, and the design and manufacturing cost of the microscopic optical system is greatly reduced; the optical Zernike phase contrast microscope can be universally used for different bright field microscopes, halo artifacts caused by interference effects in a traditional optical Zernike phase contrast microscope do not exist, finer structural features in biological cells can be distinguished, the resolution of the optical Zernike phase contrast microscope can be close to the resolution limit of objective lens design, and the technical requirements for users are greatly reduced.

According to the living cell observation device, the observation system and the observation method, a light beam generated by an illumination element arranged below a living cell is incident to a pyramid lens array module located above the living cell, the pyramid lens array module reflects the incident light beam at the same direction angle, and the reflected light beam is diffracted into direct light and diffracted light when passing through the living cell; the phase plate causes the direct light and the diffracted light to generate a phase difference, and the direct light and the diffracted light having the phase difference interfere with each other on the imaging element to generate a phase difference image of the living cells. The volume of the observation device is greatly reduced, especially the reduction in the height direction enables the observation device to be easily placed in an existing culture box, real-time and full-life-cycle observation of cells is realized, meanwhile, the pollution of the cells and the change of a culture environment are avoided, and the observation efficiency is improved. The advantages of a current phase difference type microscopic observation system in the aspect of image effects are reserved, and the requirements for precision and stability of a movement mechanism are lowered.

The invention discloses a high-precision vortex light interference displacement sensor applied to a confined space, which comprises an edge emission laser chip, a micro-nano spiral phase plate, a Dove prism, a reflector, a cover plate, a photoelectric detector, a packaging substrate and the like, and adopts an optical-mechanical-electrical integrated structure design. Micro-nano spiral phase plates are arranged at the two ends of the laser emitting chip, left-side laser becomes a vortex light beam after passing through the micro-nano spiral phase plates, right-side laser becomes a vortex light beam conjugated with the left-side laser after passing through the micro-nano spiral phase plates and Dove prisms, and the conjugated vortex light beams on the left side and the right side enter a grating after passing through a reflector and a lens. After grating diffraction, diffraction beams of the conjugate vortex beams on the left side and the right side are converged and coherent, a vortex interference light field is received by a photoelectric detector, and then grating displacement is analyzed from a coherent light field. Miniaturization of the vortex light interference displacement sensor is achieved, and the vortex light interference displacement sensor is suitable for high-precision displacement measurement in limited space scenes in the fields of precision motion modules, precision instruments and the like.

The present disclosure relates to a method and device for removing background noise in microscopic imaging based on frequency-domain modulation. The method includes irradiating a surface of a sample to be measured by simultaneously irradiating the surface of the sample by utilizing two beams from two laser devices. One of the two beams passes through a 0˜2π vortex phase plate and then focuses on the sample to be measured to form a high-energy hollow spot, and the other of the two beams focuses on the sample to be measured to form a low-energy solid spot. The method further includes modulating the two beams in time-domain simultaneously using an electro-optic modulator and demodulating signal light at different frequencies using a lock-in amplifier, then removing the background noise by a differential process to realize a high signal-to-noise ratio super-resolution image.

This invention discloses a radar scanning device and method based on cascaded dual-phase plates. The device includes: a laser generator, a first phase plate, and a second phase plate; the light output end of the laser generator is aligned with the first phase plate, and the laser generator is used to generate an initial light signal; the first phase plate has a first phase distribution etched on its side away from the laser generator, and the first phase plate is used to perform a first-level modulation processing on the received initial light signal to obtain a first light signal; the second phase plate has a second phase distribution etched on its side facing the first phase plate, and the second phase plate is used to perform a second-level modulation processing on the received first light signal to obtain a two-dimensional grating scanning beam; wherein, the first phase distribution and the second phase distribution are designed to generate a corresponding two-dimensional grating scanning beam based on the phase difference between them, thereby enhancing the flexibility and stability of the lidar scanning system.

This application provides an intelligent optical sensing system and method for imaging in turbid underwater environments, belonging to the field of underwater optical imaging. It solves the problem of low efficiency in identifying underwater objects due to the difficulty of obtaining clear images in turbid water with existing equipment. The system includes an optical imaging module, an image acquisition module, and a computing device mounted on a diving device. The computing device runs computer programs for an image preprocessing module, a depth sensing module, and a neural network denoising and recognition module. The optical imaging module generates a structured light field carrying an orbital angular momentum mode based on a spiral phase plate. The image acquisition module acquires the reflection information of the target object after being illuminated by vortex light. The image preprocessing module enhances the acquired image. The depth sensing module obtains the current water pressure using a pressure sensor, and the computing device decomposes the current water depth. The neural network denoising and recognition module performs real-time image recognition and denoising. This application is applied to underwater imaging in turbid water.

The present invention discloses a three-dimensional correlation imaging method for underwater targets based on vortex light spatial filtering, comprising: (1) emitting pulsed laser, which is irradiated onto the underwater target after passing through a beam expander and a transmitting mirror group; (2) performing speckle encoding modulation on the light intensity distribution of the emitted or received light through a digital micromirror device (DMD); (3) filtering the light modulated by the DMD through a spiral phase plate and a mask plate with a transparent ring to achieve the filtering of scattered light and background light; (4) using a photomultiplier tube to obtain the filtered light intensity fluctuation changes and performing synchronous sampling to obtain the echo light intensities of targets at different distances; (5) performing reconstruction calculation according to the echo light intensities of targets at different distances and the speckle encoding modulation mode of the DMD to obtain the target images of different distance slices, namely three-dimensional imaging. By using the present invention, the interference of water body scattering and background light can be effectively filtered, and high signal-to-noise ratio and high-resolution three-dimensional imaging of underwater targets can be achieved.

The application discloses an extreme ultraviolet coherent diffraction stack imaging method based on random phase modulation, which is realized through an extreme ultraviolet phase modulation stack imaging light path of a random phase plate. The imaging light path comprises a high harmonic light source, a pinhole, a phase plate and a photoelectric coupling detector. The high harmonic light source emits light to irradiate a probe. A sample to be measured is arranged between the pinhole and the phase plate. The phase plate is used for phase modulation. The light irradiated by the probe is irradiated onto the sample to be measured through the pinhole, propagates a preset distance, and then reaches the plane of the photoelectric coupling detector through the phase plate. The diffraction pattern of the sample to be measured is obtained. Iterative processing is performed on the first amplitude information of the emergent light, the second amplitude information of the reverse propagation, the first diffraction pattern light field and the first diffraction pattern light spot. The best sample to be measured pattern is obtained, and the best sample to be measured information and the best light irradiation probe information are separated. The method can realize lensless imaging, avoids aberration and aperture limitation caused by the use of a lens, and has a simpler system and lower cost.

The application discloses a vortex light interference device and method for measuring three-dimensional vibration and sound field rotation characteristics, wherein a helium-neon laser emits laser light, the laser light passes through a half-wave plate and a first polarization beam splitter prism, and is divided into object light and reference light; the object light passes through a first spiral phase plate and becomes vortex object light, the vortex object light passes through a second polarization beam splitter prism, a quarter-wave plate, and a beam expander lens, and is irradiated on a test sample surface, reflected light of the sample surface passes through the beam expander lens, the quarter-wave plate, the second polarization beam splitter prism, a beam splitter prism and a focusing lens, and is irradiated on a photodetector; the reference light passes through an acousto-optic modulator to generate frequency modulation, passes through a mirror and a second spiral phase plate to become frequency-modulated vortex light, and the vortex light passes through a beam splitter prism and a focusing lens and is irradiated on the photodetector; a computer calculates and demodulates frequency-modulated signals of the photodetector and modulation signals of the acousto-optic modulator, and finally obtains three-dimensional vibration information and sound field rotation characteristics of the sample.

The invention provides a high-precision multi-plane optical converter installation and adjustment method and an optical converter, and belongs to the field of optical path installation and adjustment testing. The problems that an existing method is tedious in debugging step and long in time consumption and lacks an effective compensation mechanism for the multi-degree-of-freedom coupling error are solved. The method comprises the following steps: adjusting relative positions and postures of a reflector and a phase plate according to optical feedback, so that the reflector is parallel to the phase plate; adjusting the position of the collimation single-mode optical fiber array relative to the phase plate according to the auxiliary positioning optical fiber and the phase modulation; and adjusting the position of the collimation multimode optical fiber according to the output power maximization. The method is mainly used in the free space optical communication field.

The present invention relates to the field of optical device technology, and in particular to a terahertz vortex phase plate based on a dual-band staggered metasurface. The metasurface is composed of a number of periodically arranged metasurface units, and each metasurface unit is composed of a metal structure layer, an intermediate dielectric layer, and a metal reflective layer from top to bottom; the metal structure layer includes two concentrically arranged metal opening rings, and the rotation angles of the two metal opening rings are controlled to generate vortex beams with different topological charges at different frequencies, and the electromagnetic coupling between the two metal opening rings is controlled to achieve phase control at different frequency bands based on a single rotation of each metal opening ring. The phase plate of the present invention has a simple and thin structure, which is convenient for integrated installation while reducing costs. Secondly, without introducing phase change materials, it can realize independent control of terahertz waves in two different frequency bands, meet the generation requirements of multi-modal vortex beams, and improve spectrum utilization.

The invention relates to a manufacturing method of a phase plate and the phase plate. The manufacturing method comprises the following steps: providing a substrate; forming grooves and lug bosses, which are alternately distributed, on the substrate; arranging a shielding frame on the substrate, wherein the shielding frame forms a phase modulation region in a surrounding manner; wherein the edge of the groove is covered by the shielding frame. According to the manufacturing method of the phase plate provided by the invention, the shielding frame covers the edge of the groove, so that the influence of process deviation in the processing process is reduced, and the manufacturing yield of the phase plate is improved.

The invention discloses a wireless cross-domain acoustic communication system and method based on acoustical holography. The acoustical holography device used for cross-domain acoustic communication is composed of a single-layer acoustical holography phase plate, an array transducer and a camera vision module, each array element of the array transducer has a connected state and a non-connected state, and after a communication coding signal transmitted in water is received, the single-layer acoustical holography phase plate is connected with the camera vision module through the single-layer acoustical holography phase plate. The transducer array elements at the corresponding positions can be sequentially gated according to the sequence, dynamic regulation and control of an incident sound field are realized, the incident sound field passes through the single-layer holographic phase plate and is subjected to phase modulation to be transmitted to a water-air interface, the interface is deformed under the action of acoustic radiation force, and the camera vision module is used for capturing, analyzing and decoding the water surface deformation condition, so that the water surface deformation condition is obtained. And information wireless receiving across a water-air interface is completed. According to the invention, underwater information can be directly transmitted to the air, the equipment is simple, the requirement on the relative position of transmitting-receiving equipment is not strict, and the device is suitable for a liquid environment with any temperature, salinity and density.

The invention discloses a device and a method for measuring a complex amplitude transmittance function of a lens. The device comprises a laser, a focusing lens, a random phase plate, a sleeve, a photoelectric detector and a computer, a focusing lens, a random phase plate, a sleeve and a photoelectric detector are sequentially arranged along the direction of coherent light emitted by the laser, the random phase plate is fixed at the front end of the sleeve, the rear end of the sleeve is connected with the photoelectric detector, and the random phase plate, the sleeve and the photoelectric detector can move; the random phase plate is parallel to the target surface of the photoelectric detector and is perpendicular to the incident direction of the light beam, a to-be-detected lens is arranged in front of the random phase plate, and the photoelectric detector is connected with a computer. The photoelectric detector is used for recording the two diffraction light spots, the computer is used for conducting iterative calculation to achieve measurement of the complex amplitude transmittance function of the lens, the measurement is not limited by the pixel size of the detector, the influence of the environment is small, the measurement resolution is high, and the requirement for measurement of the complex amplitude transmittance function of the lens is met.

A system and method for surface profile determination includes generating a plurality of interactions between a surface (360) and a set of particle beams (332, 223), and recombining the set of particle beams after interacting with the surface to determine a surface depth profile. The set of particle beams may include a particle beam split (340, 342) into a reference beam (334) and a sample beam (332), a particle beam passing through a Zernike phase plate or other phase splitter, or a set of particle beams having different focal lengths. The particle beam may be recombined holographically, by interference, mathematically (such as based on intensity, phase, amplitude, etc.), where the recombining method may vary based on the type of particle beam used.

This invention provides a method for charged particle beam (CPB) phase contrast imaging. [Solution] In a CPB system, the phase contrast image is obtained by directing a sample-modulated CPB to the phase plate so that it has a diffraction plane displaced from the phase plate. Based on the interference fringes of the image, the lateral displacement of the CPB relative to the phase plate can be estimated and adjusted.

The present invention discloses a method for generating a terahertz Airy beam based on an electrically controlled liquid crystal cubic phase plate, belonging to the field of terahertz signal modulation technology, and includes the following steps: S1. calculating and manufacturing the structural electrode pattern required for the cubic phase plate; S2. photolithography of a DMSO-doped PEDOT:PSS organic thin film using a lift-off process to manufacture a structural electrode with a cubic phase pattern; S3. utilizing the structural electrode to load a vertical electric field to drive the liquid crystal to manufacture the liquid crystal cubic phase plate required for generating the Airy beam; S4. utilizing the terahertz liquid crystal cubic phase plate to achieve Airy beam generation. The present invention utilizes the aforementioned method for generating a terahertz Airy beam based on an electrically controlled liquid crystal cubic phase plate to manufacture a terahertz Airy beam generating device with a short production cycle and low cost, and exhibits excellent broadband optical anisotropy and electro-optical and magneto-optical modulation properties. It can achieve large operating bandwidth and tunable performance requirements, helping to accelerate the practical application of terahertz imaging technology.

The present invention relates to the technical field of multiplexing and demultiplexing devices in space division multiplexing, and more specifically, to a mode group demultiplexing method and device based on a cascade diffraction network. The mode group demultiplexing method adopts a strategy of non-deterministic mode conversion to design and optimize the cascade diffraction network, which improves the freedom of the output mode field, so that the phase plate design can be carried out with greater freedom, thereby significantly improving the efficiency of beam conversion and greatly reducing the number of phase plates required. The present invention overcomes the shortcomings of low energy efficiency and stability in mode group demultiplexing, and reduces device loss by improving and optimizing the design.

A programmable 3D beam shaping device based on beamlet printing technology, comprising a laser source, the laser source emits initial laser, the initial laser adjusts the polarization state through a rotatable half-wave plate, and then is separated into orthogonal s component beam and p component beam through a first polarization beam splitter prism; the p component beam is expanded and then enters a Dammann grating to generate a diffraction beam containing several diffraction orders; the diffraction beam passes through a second polarization beam splitter prism, a quarter-wave plate and a first focusing element in turn, introduces focal shift by a multi-stage phase plate array, adjusts the angle and position offset of the sub-group of the sub-beam array beam by a spatial light modulator to generate a working beam, the working beam returns to the second polarization beam splitter prism from the original light path and is emitted into a working area by a second focusing element, generating a three-dimensional light field; the device can accurately control the three-dimensional irradiance distribution in the processing area, thereby realizing multi-level and depth-adjustable energy deposition, and significantly improving the quality, efficiency and consistency of processing.

The present invention discloses a mechanically modulated optical encryption system and a dynamic holographic image switching method. The system includes a light source, a composite phase plate, a convex lens and an image acquisition device arranged in sequence. The composite phase plate includes two phase plates arranged in parallel. The two phase plates are encoded with vortex phase information. The image phase is increased on one of the phase plates. At least one of the phase plates is connected to a rotation drive device, which is used to modulate the phase of the corresponding phase plate. The light beam emitted by the light source is modulated by the composite phase plate and outputs vortex light. The topological charge of the vortex light is adjusted by regulating the relative rotation amount of the two phase plates. At the same time, a dynamic holographic image switching method based on the above system is disclosed. The relative rotation angle of the two phase plates is related to the topological charge of the output vortex light. A simple composite phase plate structure is used to realize single-beam multi-topological charge output, reduce system complexity, and store high-density information with only two phase plates at low cost.