89 results about "Polarization beam splitter" patented technology

The application discloses a Stokes parameter encoder, which comprises a fiber optical circulator and an optical path round trip path; a polarization maintaining fiber Faraday rotator is arranged on the optical path round trip path to rotate the polarization of light by 45 degrees; the fiber optical circulator is a polarization maintaining fiber optical circulator; the fiber optical polarization beam splitter is a polarization maintaining fiber optical polarization beam splitter; the delay fiber is a polarization maintaining delay fiber; and the fiber optical phase modulator is a polarization maintaining fiber optical phase modulator. The application further discloses a parameter encoding method of the encoder. The above technical scheme can perfectly offset the rotation angle deviation problem caused by the device, can guarantee the stability of the rotation angle regardless of the angle deviation of the device, is easy to realize the driving circuit, is easy to integrate and small in size due to the pure fiber structure, and can realize the continuous variable quantum key distribution of the complete GG02 protocol based on the Stokes encoder.

This application provides an identification device and method for soybean grain screening equipment in soybean milk production. The device scans and images the soybean surface. A polarization beam splitter in the camera's optical path separates the reflected light from the soybean surface into parallel polarized light and orthogonally polarized light with mutually perpendicular polarization directions, acquiring parallel and orthogonal polarized images. The parallel and orthogonal polarized images are adaptively fused to generate a polarization-fused image that suppresses surface reflection interference and enhances structural information. Texture periodic features characterizing the regularity of the soybean skin texture and distortion energy features characterizing the degree of surface undulation are extracted from the polarization-fused image. The texture periodic features and distortion energy features are input into a pre-constructed feature discrimination model for defect identification. Based on the defect identification results, it is determined whether defects exist on the soybean surface. Using the scheme of this application, polarization-fused imaging can suppress surface reflection interference, thereby improving the accuracy of soybean surface defect detection.

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.

This invention discloses a noise reduction method for electromagnetic measurements of Rydberg atoms. This method constructs a 509nm coupled optical closed-loop circulation system comprising a polarization beam splitter, a half-wave plate, and a high-reflection mirror. This enables multiple reciprocating propagations of the laser within the atomic gas chamber. Utilizing the optical path circulation mechanism, the coupling strength between light and atoms is significantly improved without increasing the laser source power, thus greatly enhancing the excitation efficiency of Rydberg states. Simultaneously, this structure allows the intermediate frequency carrier signal to linearly and coherently superimpose with the number of cycles, while the laser background noise accumulates incoherently only according to a square root law, thereby significantly improving the measurement signal-to-noise ratio. This invention solves the problems of low excitation efficiency and difficulty in eliminating laser background noise in existing single-path optical systems, providing a new solution with high excitation efficiency and high signal-to-noise ratio for high-sensitivity microwave electric field measurements.

Embodiments of the present disclosure relate to an optical scanning system, a laser radar and a vehicle. The optical scanning system includes a polarization converter, a polarization beam splitter, a phase delay element, and a scanning element. The polarization converter is configured to receive a first light having a first polarization state and a second light having a second polarization state and emit a third light having the second polarization state. The polarization beam splitter is configured to reflect the third light. The phase delay element is configured to receive the third light and emit a fourth light. The scanning element is configured to receive the fourth light and emit a fifth light. The phase delay element is further configured to convert the fifth light into a scanning light having the first polarization state, and the polarization beam splitter is further configured to transmit the scanning light.

The application provides a distributed optical fiber acoustic wave sensing system and a pattern recognition method. The application relates to the fields of optical fiber sensing and pattern recognition, and the system comprises the following steps: continuous coherent light emitted by a narrow-line-width laser is split into two paths by a beam splitting fiber coupler, one path is used as local reference light, and the other path is used as probe light; the probe light is modulated into optical pulses in an acousto-optic modulator driven by a waveform generator, and the optical pulses are injected into a measured sensing optical fiber through a fiber loop; Rayleigh backscattering light returned through the measured sensing optical fiber is mixed with the local reference light through the fiber loop, and the mixed light is decomposed into two orthogonal polarized light beams in a polarization beam splitter and is transmitted to a first balanced photodetector and a second balanced photodetector respectively to be converted into electrical signals; and the two orthogonal interference electrical signals are synchronously collected by a data acquisition card and are sent to a host computer for demodulation. The application provides a new distributed acoustic wave monitoring method with high reliability and high generalization ability, and has extremely high engineering popularization value.

This invention discloses a liquid crystal filter-based lidar chopping device for atmospheric wind and temperature detection, comprising a digitally controlled voltage output module, a liquid crystal module, a light guide module, a timing control module, a polarization beam splitter module, a frequency discriminator module, a reference channel photodetector, a frequency discriminator channel photodetector, a photon counting and acquisition card, a computer, a pulsed laser, a telescope, and a collimation module. This invention also discloses a liquid crystal filter-based lidar chopping method for atmospheric wind and temperature detection. This invention solves the problem of atmospheric wind and temperature detection being limited by the dynamic range of the photodetector; the received signal attenuation amplitude can be adaptively adjusted in real time, better adapting to weather changes. Furthermore, although liquid crystal filtering introduces some signal loss, wind and temperature detection typically uses the ratio of the reference channel and frequency discriminator channel signals for inversion, so the final result is independent of the liquid crystal's transmittance, thus avoiding the negative impact of liquid crystal filtering.

The application discloses an SBS phase conjugation mirror capable of displaying a sound wave field in real time, and belongs to the technical field of nonlinear optics.The application comprises the following steps: pump light passes through a half-wave plate and a polarization beam splitter, passes through an optical isolator, changes a polarization state through a quarter-wave plate, is focused through a focusing lens, and then enters an SBS medium pool, stimulated Brillouin scattering occurs, a periodic density modulation is formed in the medium, and an equivalent acousto-optic grating structure is generated.Through introducing an independent probe light beam, the probe light enters the SBS medium pool at an incident angle satisfying the Bragg diffraction condition, and the probe light will be diffracted on the acousto-optic grating formed by the sound wave field.The intensity of the diffracted light changes with the intensity of the sound wave field, so that the real-time measurement of the sound wave field waveform and the life parameter in the SBS process can be realized by detecting the change of the diffracted light intensity with time.

The application discloses a laser converging system, a laser welding system and a laser welding machine, and relates to the technical field of optical converging. The laser converging system converts the preset S polarization laser beams sent by a laser device into two S polarization beams, and then into two P polarization beams through a plane mirror, an S polarization beam splitter, a first controlled mirror and a second controlled mirror arranged in the same XY plane, and converges the first light path and the second light path corresponding to the two P polarization beams at a preset space point outside the XY plane, so that the imaging light path for observing the converging conditions of the P polarization beams is designed outside the XY plane where the laser transmission light path is located, the mutual interference between the laser transmission light path and the imaging light path is avoided, and the control precision of the laser convergence is improved.

The application belongs to a polarization Michelson wind measurement interferometer, and aims at the technical problems of resolution reduction, instrument volume and weight increase caused by internal movement components or aperture division of the existing wind imaging interferometer, and provides a polarization Michelson wind measurement interferometer based on LCVR and a measurement method thereof. Incident light is sequentially divided into transmitted light and reflected light after passing through a front telescope system, a first linear polarizer and a polarization beam splitter. The transmitted light forms first linearly polarized light by passing through a first compensation glass, a second compensation glass and a first achromatic quarter-wave plate. The reflected light forms second linearly polarized light by passing through a third compensation glass and a back surface of a second achromatic quarter-wave plate. The first linearly polarized light and the second linearly polarized light have an optical path difference and orthogonal polarization directions. The first linearly polarized light and the second linearly polarized light are sequentially imaged on a surface array CCD after passing through a first imaging lens, an aperture diaphragm, a second imaging lens, an LCVR and a second linear polarizer.

The application discloses an optical signal inner circulation delay system based on electro-optic polarization modulation, comprising a signal light source, a first polarization beam splitter prism, a first electro-optic polarization modulator, a second polarization beam splitter prism, a second electro-optic polarization modulator, a third polarization beam splitter prism, a first full reflection mirror, a first lens, a first optical fiber collimator, a single-mode / multi-mode optical fiber, a second lens, a second optical fiber collimator and a second full reflection mirror, forming a ring-shaped light path. The length of the single-mode / multi-mode optical fiber and the high level duration of the modulation electric signal are adjusted, the repetition frequency and the pulse width of the output optical signal can be changed respectively, and therefore the application can also be used for converting continuous light into controllable pulsed light. The number of times that the signal light circulates in the ring-shaped light path can be controlled through the loaded electric signal, the delay time is flexibly adjusted, and the delay time range is expanded.

The application provides an optical scanning system, which comprises a polarization converter, a polarization beam splitter, a phase delay element and a scanning element. The polarization converter receives first light with a first polarization state and second light with a second polarization state, and is configured to convert the polarization state of the first light into the second polarization state and to emit the first light and the second light together as third light with the second polarization state. The polarization beam splitter receives and reflects the third light. The phase delay element is configured to receive the third light and emit fourth light with a third polarization state. The scanning element is configured to receive the fourth light and emit fifth light with a fourth polarization state towards the phase delay element, and is further configured to change the emission angle of the fifth light. The fifth light emitted from the scanning element is converted into scanning light with the first polarization state by the phase delay element, and the polarization beam splitter is configured to transmit and emit the scanning light. The application further provides a laser radar using the optical scanning system and a vehicle.

This invention provides a low-crosstalk signal demodulation device and method for fiber optic laser communication, belonging to the field of fiber optic communication technology. The device includes a fiber optic signal input port, an optical circulator, a polarization beam splitter / combiner module, a balanced photodetector unit, a low-noise amplification and quadrature demodulation module, an adaptive crosstalk cancellation unit, a MIMO equalization and decision unit, and a digital signal output port, connected in series according to the signal flow direction. It also includes a crosstalk monitoring and feedback unit bidirectionally connected to the low-noise amplification and quadrature demodulation module, the adaptive crosstalk cancellation unit, and the MIMO equalization and decision unit. This invention, employing the aforementioned low-crosstalk signal demodulation device and method for fiber optic laser communication, overcomes the limitations of traditional single-domain crosstalk suppression. Through the synergistic effect of optical path, circuit, and algorithm layers, it effectively suppresses crosstalk caused by multi-channel multiplexing, polarization mode dispersion, and backscattering, significantly improving demodulation accuracy, anti-interference capability, and system stability.

The application discloses a kind of high stability optical parametric oscillator assisted by intelligent feedback algorithm, and relates to the technical field of optical parametric oscillator.The oscillator includes 515 nm pump laser source, half-wave plate, polarization beam splitter, plane mirror, dichroic mirror, concave focusing cavity mirror, nonlinear crystal, output coupling mirror, four-quadrant photodetector based on STM32, DAC high-voltage drive board and piezoelectric deflection mirror.The application utilizes four-quadrant photodetector to monitor laser output power in real time, and collects data through the combination of ADC and direct memory access (DMA), realizes double buffering operation by means of full transmission and half transmission mechanism, to efficiently obtain the performance indicators required by SPGD algorithm.The algorithm continuously iterates and optimizes, controls piezoelectric deflection mirror in real time, precisely adjusts cavity length and beam pointing, and effectively stabilizes laser output power.

A diffractive optical element comprising at least one achromatic half-wave plate and at least one chromatic half-wave plate, each half-wave plate comprising at least two layers of a polymerized chiral liquid crystal (LC) material on a substrate, wherein at least one of the substrates has a periodic surface grating, a method for its preparation. Also, its use in optical or electrooptical components or devices, especially for digital optics or augmented reality or virtual reality (AR / VR) applications like non-mechanical beam steering elements, optical waveguides, optical couplers, optical combiners, optical deflectors, polarization beam splitters, partial mirrors or lenses.

This application relates to a method for enhancing the quality of wafer dark-field defect detection images. The method includes: under conditions of wafer micro-vibration, separating the dark-field scattered light from the wafer surface into two orthogonal polarization components, an s-polarization channel and a p-polarization channel, using a polarization beam splitter; acquiring time-series image sequences corresponding to the s-polarization channel and the p-polarization channel respectively; processing the time-series image sequences to obtain a standard image sequence; calculating the time-series gray-level variation coefficient of each pixel position in the s-polarization channel and the p-polarization channel respectively, and calculating the time-series gray-level cross-correlation coefficient F between the s-polarization channel and the p-polarization channel; determining the background roughness scattering region and the defect scattering region based on the time-series gray-level variation coefficient, and forming suppression weights based on the determination results; acquiring a residual gray-level image; and performing nonlinear gray-level stretching on the residual gray-level image to obtain a defect detection image with enhanced signal-to-noise ratio. This invention can improve the image signal-to-noise ratio.

This invention relates to a photonic Nyquist folding receiver system based on polarization multiplexing, comprising: N The first laser and optoelectronic modulator, the second i The laser generates continuous light that enters the first... i Photoelectric modulator, number i The RF input port of the upper arm of the optoelectronic modulator is connected to a carrier signal, the first i The RF input port of the lower arm of the optoelectronic modulator is connected to a binary symbol sequence; N The output optical signals of the photoelectric modulators are coupled and input to two Mach-Zehnder modulators. These two modulators are then connected to the signal under test (SUT) and the SUT processed by a delay circuit, respectively. One output optical signal passes through a polarization rotator and becomes orthogonal to the polarization state of the other optical signal. The two signals are coupled by a polarization beam combiner to output an orthogonally polarized multiplexed optical signal. This signal is then separated by a polarization beam splitter, and the two orthogonally polarized signals are fed into two photodetectors and two low-pass filters for low-pass filtering. Finally, the original frequency of the SUT is obtained by analyzing the frequency and phase difference of the two low-frequency signals. This invention can accurately recover the frequency of the SUT with low structural complexity.

This invention relates to a high-efficiency laser, belonging to the field of laser technology. The high-efficiency laser includes a laser source, a first half-wave plate, a polarization beam splitter, a frequency conversion element, a first transmission mirror, and a second transmission mirror. The laser source emits a laser beam, which sequentially passes through the first half-wave plate, the polarization beam splitter, and the frequency conversion element. The laser beam converted by the frequency conversion element is transmitted through the first transmission mirror to form a first sub-beam, and the unconverted laser beam is reflected to form a second sub-beam. Within the second sub-beam, the laser beam converted by the frequency conversion element passes through the second transmission mirror to form a third sub-beam, and the unconverted laser beam is reflected to form a fourth sub-beam. The reflected fourth sub-beam, after passing through the polarization beam splitter, is again converted by the frequency conversion element and emitted towards the first and second transmission mirrors. This high-efficiency laser combines the frequency-converted laser beams multiple times for output, improving the energy utilization rate of the laser.

Laser radar include two part objective lenses that are used for imaging a target and directing probe beams to the target. Portions of tracer beams that degrade target images are attenuated with dichroic filters that block central portions of tracer beams. Local oscillator beams can be produced with a mixing lens that directs probe beams through a polarizing beam splitter to focus at or on a waveplate so that portions are reflected from the waveplate as local oscillator beams. An imaging system that is confocal with a probe beam is coupled to provide target measurements or to establish a focus of the probe beam.

This application provides a 1-to-4 polarization-maintaining fiber optic isolator, relating to the field of optical fiber communication technology. The 1-to-4 polarization-maintaining fiber optic isolator includes a housing and an optical component module disposed within the housing. The optical component module includes an input unit, a polarization beam splitter unit, a Faraday rotation unit, a half-wave plate unit, and an output unit. The input unit ensures that the light is input with a 45° polarization state through a polarization-maintaining fiber collimator. After being filtered to 0° or 90° polarization by a polarization beam splitter, it is corrected to a specific polarization state by a half-wave plate, then rotated counterclockwise by 45° by a black plate, and finally corrected to 0° polarization by a ±22.5° half-wave plate, outputting four horizontal signals. This invention achieves four-channel optical isolation integrated in a single housing, with a compact size and low loss.

Disclosed herein are a vehicle holographic head-up display apparatus and a method for providing hologram using the same. The vehicle holographic head-up display apparatus includes a holographic projection module including two spatial light modulators configured to generate a hologram pattern by modulating laser light separated through a polarization beam splitter, and including a single optical system shared by the left and right eyes, and a windshield module having an increased optical path based on reflection of light.

This invention relates to a method for preparing vector Hermitian-Laguerre Gaussian beams based on collinear interference. Combining the relationship between the Poincaré sphere and the Jones matrix, and based on the vortex light field generated by the complete solutions of two sets of Helmholtz equations, a method for preparing vector Hermitian-Laguerre Gaussian beams based on collinear interference is proposed. Unlike the commonly used single-mode vector light field preparation, this method, based on a phase-type spatial light modulator, a polarization beam splitter, and a half-wave plate, realizes the preparation of a dual-mode vector Hermitian-Laguerre Gaussian beam, reconstructs the polarization distribution on its intensity cross section, and studies the influence of mode difference on the polarization distribution with transmission distance. Compared with traditional single-mode vector light fields, this method achieves good results in preparing vector light fields with different modes. This method belongs to the category of light field manipulation and can be applied to the design of optical polarization elements.

Lighting module for a motor vehicle. Combination device (10, 100) of at least two light sources for a motor vehicle lighting module, characterized in that it comprises at least two light sources (11, 14; 31, 32) of substantially the same colors, which are single-mode or multi-mode laser diodes, in that said at least two light sources (11, 14; 31, 32) are capable of emitting a respective light beam (1, 4; 51, 52) of different polarization, and in that it comprises a polarization beam splitter (43) arranged so as to superimpose two light beams (1, 4; 51, 52) which would be emitted respectively by the at least two light sources (11, 14; 31, 32) to generate a single output lighting beam (5; 55). Figure for the abstract: Fig. 1

This invention provides a method and system for on-orbit polarization state correction of spaceborne laser signals. First, the rotation direction and pulse parameters required for switching between left- and right-hand circular polarization states are calibrated on the ground, from zero position to the default polarization state. During on-orbit operation, the motor is driven back to zero or polarity switching is performed based on the ground calibration parameters to resolve the issue of unclear rotation direction caused by command errors. To address environmental drift and accumulated errors, the characteristic of a laser corner bevel prism to reverse the rotation direction of the returning light is utilized, combined with the physical properties of orthogonally linearly polarized light from a polarization beam splitter, to fine-tune the rotating motor and monitor the energy received by the detector in real time. When the received energy reaches its peak value, it is determined to be the optimal polarization state under the current environment, achieving closed-loop circularity optimization and performance correction. This method eliminates dependence on interstellar links and effectively solves the problems of on-orbit parameter drift and multi-parameter coupling debugging of open-loop motors.

This invention discloses a differential interferometric phase-contrast imaging system, method, and time-difference incubator device, belonging to the fields of optical imaging and medical device technology. The system includes an illumination source module, a microscopic imaging module, a polarization interferometry module, and a quantitative phase image reconstruction module. By placing all polarization interferometry components, such as the polarizer and polarization beam splitter, on the image side of the microscopic imaging module, the imaging beam does not need to pass through the plastic culture dish before passing through the polarization elements, thus completely avoiding interference from plastic birefringence on the imaging and achieving high-quality observation of samples in cell biology or materials science fields within plastic culture dishes. Simultaneously, the system uses a polarization camera to simultaneously acquire multiple phase-shifted interferograms in a single exposure, combined with a quantitative phase reconstruction algorithm, achieving high-speed, high-precision quantitative phase imaging, overcoming the shortcomings of traditional mechanical phase-shifting methods, such as slow speed and susceptibility to motion artifacts. Furthermore, the imaging system of this invention can also be integrated into a time-difference incubator.

An apparatus for emitting an incident laser beam that is a linearly polarized laser beam at a predetermined intensity, includes: an intensity changing optical element (polarization beam splitter) disposed on the optical path of the incident laser beam, for changing the intensity of an outgoing laser beam by allowing a transmission of a component of the incident laser beam polarized in a predetermined variable transmission direction and to rotate around the optical axis of the incident laser beam within a range of at least 90° with respect to a predetermined reference angle; and a polarization direction changing optical element (concave lens) disposed upstream the optical path of the incident laser beam with respect to the intensity changing optical element, and for changing the polarization direction of the incident laser beam and to emit the incident laser beam, the change direction being variable.

This invention provides a laser illuminator and a method for suppressing its instantaneous peak power, belonging to the field of laser illuminator technology. It includes: a pump module, a shaping lens group, a gain medium, a total reflection mirror, an output mirror, a right-angle prism, a polarizing beam splitter, and a Q-switching switch. The output mirror and the total reflection mirror are arranged opposite each other to form a resonant cavity. The shaping lens group is disposed between the pump module and the total reflection mirror. The gain medium is disposed between the shaping lens group and the incident light path of the right-angle prism. The polarizing beam splitter is disposed between the exit light path of the right-angle prism and the exit mirror. The Q-switching switch is disposed between the polarizing beam splitter and the exit mirror. A narrowband filter is also disposed within the resonant cavity, and the narrowband filter is disposed on the resonant light path between the total reflection mirror and the output mirror. This invention effectively reduces the instantaneous peak power and improves the lifespan of the device.

This invention discloses a linear polarization beam splitting unit and a real-time monitoring device and method for the polarization degree of a linearly polarized laser. The monitoring device includes a polarization modulation unit, a polarization beam splitting unit, a photoelectric detection unit, and a signal processing unit. The polarization beam splitting unit includes a first polarization beam splitter and a second polarization beam splitter. The first polarization beam splitter receives the test light and splits it into a first transmitted light and a first reflected light. The first reflected light serves as the incident light for the second polarization beam splitter, which further splits the first reflected light into a second transmitted light and a second reflected light. This invention completely separates and extracts the main polarization component leaked by the first polarization beam splitter due to factors such as installation angle deviation, thermal drift, and mechanical vibration, using the second polarization beam splitter, directly restoring the true power extreme value of the orthogonal polarization direction of the laser under test.

A multi-twist waveplate comprising at least two layers of a polymerized chiral liquid crystal (LC) material on a substrate containing a surface grating, a method for its preparation, and its use in optical or electrooptical components or devices, especially for digital optics or augmented reality or virtual reality (AR / VR) applications like non-mechanical beam steering elements, optical waveguides, optical couplers, optical combiners, polarization beam splitters, partial mirrors or lenses.