225 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 discloses a terahertz vortex phase plate based on a dumbbell-shaped metasurface. A plurality of metasurface units arranged on the same plane; the metasurface unit comprises a top basic unit metal structure layer, a middle dielectric layer and a substrate metal reflecting surface layer; the top basic unit metal structure layer is of a dumbbell-shaped structure, and the area is smaller than that of the middle dielectric layer and the base metal reflecting surface layer; the positions of all layers of the multiple metasurface units are correspondingly arranged, the phase distribution of the arranged multiple top layer basic unit metal structure layers on the plane meets the vortex beam phase distribution, and a metasurface array with the target topological charge is formed; the metasurface array is a terahertz wave incident plane. On the basis of improving the working efficiency, the metasurface technology and the geometric phase principle are combined, the whole-column arrangement of the terahertz vortex phase plate and the generation of terahertz vortex light beams with different topological charges are completed by designing a reflection type basic unit structure, and then the phase coverage corresponding to the specified topological charges is realized.

The invention discloses a high-precision fluorescence modulation super-resolution microscopic imaging method which is applied to the technical field of optical microscopic imaging. According to the novel high-precision fluorescence modulation super-resolution imaging technology, first-order Bessel annular light with a smaller point spread function is used for replacing common annular light generated by modulating Gaussian light through a vortex phase plate in the traditional technology, and the problem that the resolution ratio is insufficient in an existing fluorescence subtraction microscopy technology can be solved. The problem of image distortion caused by a negative side lobe is solved, the visibility and authenticity of a fine structure in an image are enhanced, and when any type of laser scanning confocal microscopy system and a fluorescence subtraction super-resolution imaging technology are oriented, only a wavefront control light path comprising a spatial light modulator and a Fourier lens needs to be added in an optical system, and the optical system can be used for controlling the optical system. Compared with the traditional super-resolution technology, the technology has the advantages that the complexity and cost of the system are reduced, the harm of photobleaching is reduced, the technology can be combined with other imaging technologies for use, and the imaging precision and the imaging quality are improved.

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.

The invention discloses a high-order non-interference quantitative phase imaging system and method based on single exposure, and belongs to the technical field of optical microscopic imaging. The microscope module comprises a halogen lamp, a condenser, an annular diaphragm, a sample, an objective lens, a phase plate, a lens I, a reflector and a lens II which are sequentially arranged along the light beam propagation direction, and the light splitting modulation module comprises a lens III, a light splitting module I, a light splitting module II, a spatial light modulator, a lens IV and a CMOS camera which are sequentially arranged along the light beam propagation direction. By adopting the single-exposure-based high-order non-interference quantitative phase imaging system, the advantages of stable structure, insensitivity to environmental interference, high phase sensitivity, low spatial noise and the like of a white light illumination system are reserved.

The invention discloses a method and system for generating an ultrafast pulse string with time-varying space-time characteristics, and relates to the technical field of laser pulse control, and the method comprises the following steps: after an incident light pulse is reflected by a first grating and collimated by a first cylindrical lens, the spectral component of the incident light pulse is expanded along the space on the plane where a phase plate is located; realizing time domain positive Fourier transform to form two-dimensional space-spectrum distribution; modulating a phase plate, and performing complex amplitude modulation on the two-dimensional space-spectrum distribution by using the phase plate to obtain a space-spectrum; the modulated space-spectrum passes through a second lens and a second grating to realize time domain inverse Fourier transform to obtain an output pulse; the output pulse is transmitted for a certain distance on the rear surface of the grating to form an ultrafast pulse string with time-varying space-time characteristics, time and space dimensions are regulated and controlled at the same time, more complex space-time characteristics are achieved, and time and space distribution of the pulse is accurately controlled.

An ultra-strong vortex laser phase measurement method comprises the steps that an incident Gaussian laser pulse is divided into two paths, one path of Gaussian laser pulse serves as reference light, and the other path of Gaussian laser pulse generates ultra-strong vortex laser to serve as object light after passing through an off-axis phase plate; splitting the Gaussian laser pulse and the ultra-strong vortex laser into four beams to obtain Gaussian laser pulses Er, Er (1), Er (2) and Er (3) and ultra-strong vortex lasers Eo, Eo (1), Eo (2) and Eo (3); the ultra-strong vortex laser Eo (1) and the Gaussian laser pulse Er (1) are synthesized into interference laser Ei; after the phase of # imgabs0 # is introduced into the ultra-strong vortex laser Eo (2), the ultra-strong vortex laser Eo (2) and the Gaussian laser pulse Er (2) are synthesized into interference laser Ei, pi / 2; the depth information of the surface plasma holographic grating formed by irradiating the laser Ei, pi / 2, Er, Eo and Ei on the surface of the plasma target is detected, so that the precise measurement of the ultra-strong vortex laser phase distribution is realized.

The invention provides a terahertz vortex radiation generation device based on transverse phase shaping. The terahertz vortex radiation generation device comprises an injector, a laser electron beam modulation system and a terahertz radiation section which are arranged in sequence, the femtosecond laser system comprises a femtosecond laser device, a first beam splitting piece and a first reflecting mirror which are arranged in sequence and are parallel to the electron beam transmission axis, and the first beam splitting piece divides femtosecond Gaussian laser pulses from the femtosecond laser device into a first path of femtosecond Gaussian laser and a second path of femtosecond Gaussian laser; the first path of femtosecond Gaussian laser and the injector are sequentially arranged along the light path of the first path of femtosecond Gaussian laser, and the first reflector, the pulse broadening and beam splitting system and the laser electron beam modulation system are sequentially arranged along the light path of the second path of femtosecond Gaussian laser. According to the terahertz vortex radiation generating device, the longitudinal frequency of terahertz vortex beat frequency laser can be adjusted through the spiral phase plate, the transverse orbital angular momentum of terahertz vortex beat frequency laser can be changed through the adjustable delayer, the layout is simple, the tunability is high, and the terahertz vortex radiation generating device is flexible.

The invention discloses a sidelobe-eliminating Bessel beam drilling device, and relates to the technical field of optical devices, the sidelobe-eliminating Bessel beam drilling device mainly comprises a light generation device, a beam shaping device and a regulation and control device, the light generation device is used for generating circularly polarized light; the light beam shaping device comprises a binary phase plate diffraction optical element and a Bessel light generating element, the binary phase plate diffraction optical element is used for modulating the phase of the circularly polarized light, the Bessel light generating element is used for converting the modulated circularly polarized light into Bessel light beams, the binary phase plate diffraction optical element can generate two different light beams, and the Bessel light generating element is used for generating the two different light beams. The beam shaping device comprises a first type of Bessel beams and a second type of Bessel beams, the first type of Bessel beams and the second type of Bessel beams can generate side lobe destructive interference and main lobe constructive interference, and the regulation and control device comprises a double telecentric optical system, is arranged at the tail end of the beam shaping device and can regulate and control the drilling depth and the drilling position of the beams. According to the invention, the side lobe ablation damage to the drill hole can be avoided to a great extent.

The invention discloses an infrared athermalization super-resolution imaging system and method based on wavefront coding, the system is composed of an imaging main lens group 1, a phase plate 2 and a camera 4, the phase plate 2 is rotated, low-resolution infrared images modulated by phase coding are recorded in the camera 4 in sequence, and a frequency spectrum constraint airspace is adopted to update an iterative algorithm until convergence is achieved. And therefore, the limitation of insufficient Nyquist sampling can be broken through, and the imaging quality of the phase-coded intermediate image can be effectively improved. A phase plate 2 is added on an aperture plane 3 of an infrared imaging system to perform coding regulation and control on an image, so that an infrared focal plane can output a highly consistent intermediate coding image within a certain environment temperature range, and the phase plate is rotated to acquire wavefront coding image information at different angles to realize super-resolution reconstruction of the image, so that the imaging precision is improved. And finally, athermalization super-resolution imaging between-20 DEG C and + 60 DEG C can be realized, and the imaging resolution can be improved by two times.

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.

The present application provides an optical axis calibration device based on laser collimation, the optical axis calibration device 100 comprises an adapter component 10, a collimation component 20, a support locking component 30 and a photoelectric detection device 40, wherein: the adapter component 10 is a barrel-shaped structure, and the collimation component 20 is arranged in the adapter component 10; the collimation component 20 comprises a phase plate fixing ring 21, a phase plate 22, a collimation tube 23 and a bubble level 24; the phase plate fixing ring 21 is a ring structure, the phase plate 22 is a circular structure, and the phase plate The shape of 22 matches the phase plate fixing ring 21; the collimating cylinder 23 is a barrel-shaped structure, the upper end face and the lower end face of the collimating cylinder 23 are parallel, the upper end face of the collimating cylinder 23 is provided with a circular groove 25, the shape of the groove 25 matches the phase plate 22; the lower end face of the collimating cylinder 23 is provided with a rectangular hole 26, the groove 25 and the rectangular hole 26 are coaxially arranged, the contact surface of the fixed phase plate 22 is parallel to the upper end face and the lower end face of the collimating cylinder 23, and the center of the rectangular hole 26 should coincide with the axis of the collimating cylinder 23.

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.

To make a ghost inconspicuous in an optical system which has a wide angle, is lightweight, and uses polarization light.SOLUTION: An optical system OR1 guides, to an observer, light from a display element 108 for displaying an image, and comprises a first phase plate 111, a translucent reflective surface 112, a lens 104, a second phase plate 113 and a polarization separation element 114 which are arranged in the order from the display element toward the observer. The polarization separation element reflects first linear polarized light while transmits second linear polarized light in a polarization direction orthogonal to a polarization direction of the first linear polarized light. A difference is 7% or less, between a maximum value and a minimum value of reflection rates of the translucent reflective surface in first, second and third wavelengths respectively included in a wavelength rage of 430 nm to 480 nm, a wavelength rage of 520 nm to 570nm, a wavelength rage of 600 nm to 650 nm. One of lenses included in the optical system which is the closest to the display element is a negative lens having a surface convex toward the display element.SELECTED DRAWING: Figure 2

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.

The invention discloses a terahertz Airy beam generation method based on an electric control liquid crystal cubic phase plate, and belongs to the technical field of terahertz signal modulation, and the method comprises the following steps: S1, calculating a structural electrode pattern required for manufacturing the cubic phase plate; s2, carrying out photoetching on the DMSO doped PEDOT: PSS organic thin film by using a stripping process, and manufacturing a structural electrode with a cubic phase pattern; s3, manufacturing a liquid crystal cubic phase plate required for generating Airy beams by using a method of loading a vertical electric field to drive liquid crystal through a structural electrode; and S4, generating Airy beams by using the terahertz liquid crystal cubic phase plate. According to the terahertz Airy beam generation method based on the electrically-controlled liquid crystal cubic phase plate, a manufactured terahertz Airy beam generation device is short in finished product period and low in cost, has good broadband optical anisotropy and electro-optical and magneto-optical modulation characteristics, can meet the requirements for large working bandwidth and tunable performance, and has wide application prospects. And the practical application process of the terahertz imaging technology can be accelerated.

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 invention discloses an optical machine assembly surface shape in-situ detection device and method, belongs to the technical field of optical precision detection, and aims to solve the problem that in the prior art, surface shape distortion detection cannot be carried out on an optical machine assembly in the in-situ monitoring and adjusting process. In the device, laser generated by a laser sequentially passes through a beam isolator, a beam splitter prism and a collimating mirror A, then enters a to-be-tested optical machine assembly and is reflected, reflected light of the to-be-tested optical machine assembly passes through the collimating mirror A, then enters the beam splitter prism and is reflected, and reflected light of the beam splitter prism passes through a perforated optical screen, a collimating mirror B and a phase plate and then enters a CCD camera; the CCD camera is connected with a computer system, and a light spot pattern recorded by the CCD camera is input into the computer system and used for surface shape in-situ detection. According to the method, reflected light of a to-be-measured sample is modulated through a phase plate, and sample surface shape reconstruction is achieved through a phase reconstruction algorithm based on light field diffraction iteration. The method has the advantages of high measurement precision, no need of a reference plane, high vibration resistance and the like.

The invention discloses a depth dynamic focusing acoustic lens device and method based on cascade acoustical holography. Comprising a dynamic focusing acoustic lens cascading structure which is arranged in a liquid filling cavity and is mainly formed by cascading two acoustic holographic phase plates in the axial direction, one acoustic holographic phase plate is kept fixed, the other acoustic holographic phase plate moves freely, and dynamic movement of a focus in the depth direction is achieved through axial movement and circumferential rotation; each phase holographic plate is composed of a plurality of microstructure units with different thicknesses in a close array mode, the two sides of each phase holographic plate are concave-convex and flat, and the concave-convex planes face the interior of the cavity. According to the invention, dynamic sound energy focusing can be simply and conveniently realized at a plurality of positions, so that detection and imaging of a detected object on different planes are realized, and the detection efficiency is greatly improved; when in use, the structure can be directly and tightly attached to the surface of a conventional ultrasonic transducer and the surface of a measured component, and scanning and medical treatment of different plane targets can be achieved through simple movement and rotation between holographic plate components in the structure.

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.