17 results about "Radial polarization" patented technology

The present application relates to a kind of stress line birefringence compensation method of optical current sensor, the optical current sensor includes laser source, polarizer, magneto-optical film, nanometer ring-shaped radial polarization grating, image beam and CMOS area array camera sequentially arranged in same optical path, the method includes the following steps: utilize laser source to emit light signal, under the action of current to be measured, the output signal of optical current sensor is superposed with Faraday magnetic rotatory angle θ And stress line birefringence δ, form synchronous rotating annular light spot;Determine the zero-crossing moment of the measured alternating current, the rotation angle of corresponding annular light spot is stress line birefringence δ at zero-crossing moment by CMOS area array camera and record;Based on the stress line birefringence δ of record, utilize model-free adaptive iterative learning method to predict the stress line birefringence δ of future time, and according to the prediction result, the output signal of optical current sensor is compensated.

According to the transmitting and receiving combined transducer and the self-contained underwater acoustic beacon system, the transmitting transducer has an omnidirectional transmitting working mode and a directional transmitting working mode, and stable and reliable monitoring of the beacon system in a complex water area working environment can be achieved through switching of the working modes. The transmitting-receiving combined transducer comprises a transmitting transducer and a receiving transducer which are coaxially arranged, the transmitting transducer and the receiving transducer both adopt radially polarized piezoelectric ceramic circular tubes, the inner wall surfaces of the transmitting transducer and the receiving transducer are positive electrodes, and the outer wall surfaces of the receiving transducer are negative electrodes; the positive electrode of the transmitting transducer adopts a circumferential segmented polarization form, namely the inner wall surface of the transmitting transducer is uniformly divided into eight segments along the circumferential direction for polarization to form eight segments of positive electrodes; the eight sections of positive electrodes of the transmitting transducer are divided into four groups in a radial symmetry manner; and the input voltage of the four groups of positive electrodes of the transmitting transducer is changed, and the working modes are switched.

The invention discloses a carving machining method and system based on vector pulse laser, and belongs to the technical field of laser carving, the carving machining method based on the vector pulse laser comprises the steps that linear polarization femtosecond pulse laser is split into femtosecond pre-pulse laser and picosecond main pulse laser; adjusting the pulse time delay between the femtosecond pre-pulse laser and the picosecond main pulse laser; combining the femtosecond pre-pulse laser and the picosecond main pulse laser after delay regulation and control; the femtosecond pre-pulse laser is converted into an angularly polarized femtosecond pre-pulse light beam, the picosecond main pulse laser is converted into a radially polarized picosecond main pulse light beam, and a double-pulse light beam combination of the angularly polarized femtosecond pre-pulse light beam and the radially polarized picosecond main pulse light beam is formed; and the to-be-machined workpiece is ablated and engraved through the double-pulse light beam combination. And by means of the synergistic effect of double pulses and precise time delay, the width and fusion damage of a heat affected zone are remarkably reduced, and high-precision and low-damage carving machining is achieved.

The invention provides micro-nano machining equipment based on a longitudinal light field, and belongs to the technical field of micro-nano machining, and the micro-nano machining equipment comprises a light source module which is used for providing an input light beam; the light beam shaping module is used for receiving the light beam output by the light source module and shaping the input light beam into an annular light beam; the polarization regulation and control module is used for receiving the annular light beam output by the light beam shaping module and adjusting the polarization state of the annular light beam into radial polarization; and the focusing module is used for receiving the radial polarization annular light beam output by the polarization regulation and control module and focusing the radial polarization annular light beam on a focal plane to generate a high-purity longitudinal light field. According to the device, efficient conversion from common Gaussian light to a high-purity longitudinal light field is achieved, the device can generate sub-wavelength light spots with energy highly concentrated in the axial direction, the high-purity longitudinal light field can be stably generated, transverse field interference can be restrained, and therefore the micro-nano machining resolution is improved, and breakthrough of the traditional optical diffraction limit is facilitated.

The invention provides a laser processing device which is applied to the technical field of laser processing and comprises the steps that light intensity reinforcement is conducted on a weak light area of a first light beam through a target radial polarized light beam, and the problem that in the prior art, due to the fact that a single first light beam is used for through hole processing, laser energy is weakened along with the increase of the processing depth due to the existence of a light intensity area is avoided; and the light intensity area cannot effectively etch the processing target of the to-be-processed piece in the direction of the outlet hole area, so that the shapes of the inlet hole and the outlet hole of laser through hole processing can be kept consistent, and the side wall perpendicularity deviation is reduced.

The invention discloses a pipeline internal penetrating type rotating eddy current array detection device and method. The pipeline internal penetrating type rotating eddy current array detection device comprises a mounting part, an alternating current power supply assembly, a detection coil and two excitation coils, the two excitation coils are wound on the mounting part, the winding axes of the two excitation coils are overlapped, and the two excitation coils are sequentially arranged along the winding axes; the alternating current power supply assembly is electrically connected with the two exciting coils and enables the current flow directions of the two exciting coils to be opposite; the detection coil is arranged on the installation part and located between the two excitation coils. In the scheme, the direction of the radial polarization magnetic field is perpendicular to the surface of the pipe wall all the time, and the optimal excitation condition of the eddy current skin effect is met; and the rotating eddy current field generated by induction has omnidirectional sensitivity, and no matter which angle is formed between the defect trend and the moving direction of the probe, a remarkable eddy current disturbance signal can be generated, so that the universal detection of circumferential, axial and oblique defects is realized, the missing detection is avoided, and the defect detection accuracy is improved.

The invention relates to a pump enhanced optical parametric oscillator based on a monolithic cavity PPLN crystal, a vortex light generation method and application. The pump enhanced optical parametric oscillator comprises a pump laser, a matching lens, a half-wave plate, a polarization beam splitter, a quarter-wave plate, a radial polarization converter, the PPLN crystal, a temperature control furnace, a multi-dimensional adjusting frame and a spectroscope. The two end faces of the PPLN crystal are spherical surfaces, the end faces are coated with film layers, and the PPLN crystal serves as an optical parametric oscillation cavity, so that a complex cavity mirror system is omitted; the end face of the PPLN crystal is coated with a film, so that the effect of pumping enhancement is achieved, the threshold value is reduced, the conversion efficiency is improved, meanwhile, the wavelength tuning characteristic is considered, the thermal self-locking effect and the thermal lens effect are utilized, long-time wavelength stability and power stability are achieved, and a complex stable cavity system is omitted; when pump light is converted into vortex light through the S wave plate, orbital angular momentum can be selectively transmitted to idler frequency light or signal light, intermediate infrared or near-infrared vortex light output is achieved, and a miniaturized and portable vortex light generator and multi-field application can be achieved.

The application discloses a kind of radial polarization vector light beam tight gathering light field in near-field enhancement needle tip reverse design method, utilize central axis rotation symmetry, the three-dimensional configuration of circularly symmetric conical needle tip is optimized, is converted into the reverse design of circularly symmetric rotation two-dimensional boundary line shape;With Bernstein polynomial expression two-dimensional boundary streamline relative to the deformation variable of original straight line, the reverse design of circularly symmetric rotation two-dimensional boundary line is converted into optimization finite Bernstein polynomial subterm coefficient;Robust machine learning optimization algorithm is introduced to realize reverse design;Objective function is set as needle tip tip curvature radius corresponding circular arc rotation surface local field intensity average enhancement factor;To suppress the deformation of rotating boundary to appear reverse in optimization process, with maximum deformation variable constraint circularly symmetric rotation two-dimensional boundary streamline, with nonlinear grid smoothing constraint the deformation of adjacent area of boundary line.The application realizes the efficient, customizable optimization design of streamline type near-field enhancement needle tip in specific vector light field.

The invention provides a radial polarization beam splitting metasurface and a synchronous phase shifting method thereof, and relates to the technical field of optical devices. A surface structure arranged on the substrate, wherein the surface structure is formed by a plurality of sub-wavelength structure units in an annular arrangement mode; wherein the sub-wavelength structural units on the same ring have the same rotation angle, and the rotation angles of the sub-wavelength structural units on different rings change along with the radius of the ring, so that different phase modulations can be respectively generated on the left-hand circularly polarized light and the right-hand circularly polarized light of the incident ray polarized light; therefore, the left-handed circularly polarized light or the right-handed circularly polarized light forms a divergent light beam, and the other light beam forms a convergent light beam. According to the invention, through the unique sub-wavelength structure units which are annularly arranged and of which the rotation angles change along with the radius, different phase modulation can be applied to the left-handed and right-handed components of incident ray polarized light, so that divergent and convergent light beams with orthogonal polarization states are efficiently generated, and a foundation is laid for dynamic measurement based on polarization phase shift.

The invention provides an optical voltage transformer for realizing harmonic measurement and a working method thereof. The optical voltage transformer comprises a polarizer, a BGO crystal, a wave plate, a radial polarization grating, an image sensor and a light source emitter. Based on a linear demodulation mode of phase delay, rotation of a polarization plane of linearly polarized light is converted into synchronous translation of a light spot by using a radial polarization grating, and the light spot is positioned by an image sensor to obtain a displacement difference, so that linear measurement of the phase delay is realized. And when the voltage modulation signal contains the harmonic component, the translation amount of the light spot image in the linear demodulation result is the superposition result of the action of the fundamental wave and each harmonic component. And the linear demodulation mode also belongs to a linear time-invariant mode, so that the harmonic measurement capability without distortion is realized. In addition, compensation of thermal stress birefringence is achieved through a square wave difference method, and the temperature drift problem of the optical voltage transformer in harmonic measurement is solved.

The invention provides a submicron scale processing device based on adjustable and controllable laser longitudinal energy field proportion, and belongs to the technical field of laser processing, and the submicron scale processing device comprises a laser used for emitting an original laser beam; the vector polarization modulation unit is used for performing vector polarization modulation processing on the original laser beam emitted by the laser and outputting the original laser beam as a radial polarization beam; the energy space distribution modulation unit is used for performing energy distribution modulation on the radial polarized light beam emitted by the vector polarization modulation unit and outputting a radial polarized annular light beam; and the processing unit is used for converging the radially polarized annular light beams emitted from the energy distribution modulation unit. The method has the beneficial effects that vector polarization and energy space distribution modulation are carried out on only one beam of femtosecond laser, so that the femtosecond laser can be directly etched on the surface of any material to reach the submicron scale breaking through the optical diffraction limit.

The application provides a radial polarization splitting metasurface and a synchronous phase-shifting method thereof, and relates to the technical field of optical devices, and comprises a substrate; a surface structure arranged on the substrate, the surface structure is composed of a plurality of sub-wavelength structure units in a ring arrangement mode; wherein the sub-wavelength structure units on the same ring have the same rotation angle, and the rotation angles of the sub-wavelength structure units on different rings change with the radii of the rings, so that different phase modulations can be generated on left-handed circularly polarized light and right-handed circularly polarized light of incident linearly polarized light respectively, so that the left-handed circularly polarized light or the right-handed circularly polarized light forms a divergent light beam, and the other beam forms a convergent light beam. Through the unique ring arrangement and the sub-wavelength structure units with the rotation angle changing with the radius, different phase modulations can be respectively applied to left-handed and right-handed components of incident linearly polarized light, divergent and convergent light beams with orthogonal polarization states are efficiently generated, and a foundation is laid for dynamic measurement based on polarization phase shifting.

During implementation, after a laser emits a light beam, the light beam is expanded through a beam expander, the phase and amplitude of the light beam are adjusted through a spatial light modulator and a 4f filtering unit, and then a distorted Gaussian-Schell model light beam is generated through a cylindrical prism unit; a linear polarization light beam is obtained through a polarizer, so that twisted part coherent polarized light is obtained; and then, the twisted part coherent polarized light passes through a first radial polarization converter to generate a twisted part coherent radial polarized light beam, then the twisted part coherent radial polarized light beam is recovered into linear polarized light orthogonal to the initial polarization direction through a focusing lens and a second radial polarization converter, and finally orthogonal filtering is realized through a polarization analyzer. According to the scheme of the invention, the polarization of the signal light is regulated and controlled, so that the signal light and the stray light are distinguished on the focal plane; through the effect of the optical polaroid, optical signals can be efficiently processed, stray light in a full-wave band range can be suppressed, the stability and quality of signal transmission are improved, and the optical fiber is particularly suitable for optical communication and optical detection in a complex environment. Besides, according to the scheme, the light source coherence degree is low, the crosstalk effect caused by coherence can be eliminated, the good application prospect is achieved in the communication field, and the very high practical value is achieved.

The application discloses a method for generating a radially polarized high-order twisted non-uniform correlation light beam, and the method comprises the following steps: step 1, setting a weight matrix and a kernel function; step 2, obtaining a light beam cross-spectral density matrix element by integrating the weight matrix element and the kernel function; step 3, determining a restriction condition of a twist factor; step 4, setting a restriction condition of a light beam polarization state satisfying radial polarization; and step 5, determining a cross-spectral density matrix element of the radially polarized high-order twisted non-uniform correlation light beam according to the restriction conditions of the light beam twist factor and the polarization state satisfying radial polarization. The application enriches the partial coherent vector beam regulation method and provides a novel light field model with application value for the fields of optical micro-manipulation and anti-depolarization optical communication.

The application discloses a radial polarization twisted partially coherent hyperbolic cosine beam generating system and method, wherein the semiconductor laser is used for emitting a light beam, the light beam is expanded through a beam expander, reflected to a spatial light modulator through a mirror, and the phase and amplitude of the light beam are adjusted through the spatial light modulator and a 4f filter unit; the light beam obtains linear polarization property through a polarizer, so that twisted partially coherent polarized light is obtained; the twisted partially coherent polarized light generates twisted partially coherent radial polarization light beams through a vortex wave plate, is focused through a focusing lens, and finally realizes filtering through a polarizing detector; finally, the focused light beam is collected and observed by a charge coupled device. The application provides a radial polarization twisted partially coherent hyperbolic cosine light source generating system, the optical path structure is relatively simple, the construction and debugging are difficult and the repeatability is high, the phase distribution and correlation structure of the light field can be flexibly adjusted through the spatial light modulator.

This invention relates to an AC zero-crossing compensation method for stress line birefringence in an optical current sensor. The optical current sensor includes a laser source, a polarizer, a magneto-optical thin film, and a radial polarization grating arranged sequentially on the same optical path. The method includes the following steps: emitting an optical signal using the laser source, which passes sequentially through the polarizer, the magneto-optical thin film, and the radial polarization grating. Under the influence of the current to be measured, the output signal is superimposed with the Faraday magnetostrictive rotation angle α and the stress line birefringence γ, forming a translated strip-shaped light spot; locating the position of the strip-shaped light spot using a position-sensitive detector and measuring the rotation angle of the polarization plane of the linearly polarized light; detecting the AC zero-crossing point of the current to be measured, and acquiring the rotation angle of the polarization plane measured by the position-sensitive detector at the zero-crossing point as the stress line birefringence γ; and compensating the output signal of the optical current sensor using the acquired stress line birefringence γ.