1046 results about "Polarization beam splitter" patented technology

The invention discloses a special environment laser radar system and method based on polarization modulation and laser coding. The laser radar system comprises a polarization modulation laser emitting unit, a multi-channel receiving unit and a compressed sensing reconstruction unit. The polarization modulation laser emission unit comprises a laser, a beam expanding module, a spatial light modulator, a micro galvanometer array, a spatial filter and a first focusing lens which are arranged in sequence; the multi-channel receiving unit comprises a second focusing lens, a polarization beam splitter and a single-pixel detector array which are arranged in sequence; and the compressed sensing reconstruction unit comprises a compressed sensing processing module, an image reconstruction module and a loop adaptive control module which are arranged in sequence. The anti-interference capability in a complex environment is enhanced through polarization modulation, the detection resolution and the signal-to-noise ratio are improved in combination with laser coding, the imaging quality and stability of the laser radar in a special environment are greatly improved, and the method can be widely applied to the fields of military reconnaissance, disaster rescue, unmanned driving and the like.

The invention provides a transmitting-receiving coaxial laser radar optical system, and relates to the technical field of laser radars. The optical system comprises a transmitting assembly, a polarization splitting prism, a quarter-wave plate, a common beam expanding lens group, a micro-lens array, a common lens and a receiving assembly which are arranged in sequence. Laser emitted by the emitting assembly enters the polarization splitting prism, and at the moment, a light beam is linearly polarized light, can pass through the polarization splitting prism and then pass through the quarter-wave plate to reach the shared beam expanding lens group to be collimated and expanded, and finally is emitted for illumination through the micro-lens array and the shared lens; the emergent laser beam is irradiated to an object to return an optical signal, and the returned optical signal is returned to the polarization splitting prism along an original optical path and is reflected into the receiving assembly to be received and processed; according to the invention, the beam splitter prism, the beam expander group and the micro lens array are shared, and the shared lenses are the same and share the lens group, so that the purpose of saving the manufacturing cost of the laser radar is achieved; the method is suitable for automobile automatic driving, distance detection and the like.

The invention discloses a light spot shaping device based on wave plate polarization conversion and a use method, and relates to the technical field of laser processing, the device divides random polarized light into S / P light through a first polarization beam splitter (PBS), converts the S light into P light through a first 1 / 2 wave plate, modulates the S light through a conventional silicon-based liquid crystal spatial light modulator (LCoS SLM), and converts the P light into the S light through a second 1 / 2 wave plate. And the beams are combined by the second PBS. The method comprises the steps of light splitting, polarization conversion, phase modulation, beam combining, beam expanding and focusing and the like. The double 1 / 2 wave plates are combined with the conventional PBS, the laser energy utilization rate is higher than 85%, commercial SLM equipment is adapted, the machining efficiency of the shaped annular light spots is remarkably improved compared with that of Gaussian beams, the method is suitable for laser welding and metal 3D printing, and the problems of energy waste and high cost are solved.

The invention discloses a polarization-state-based optical fiber vibration sensing system and application, and relates to the technical field of optical fiber sensing, and the polarization-state-based optical fiber vibration sensing system mainly comprises a transmitting end and a receiving end. The transmitting end comprises a laser diode, a first erbium-doped optical fiber amplifier, a first circulator, a polarization scrambler, a single-mode optical fiber link, a second circulator and a second erbium-doped optical fiber amplifier which are connected in sequence; and the receiving end comprises a polarization beam splitter, a first shunt module, a second shunt module, an optical mixer, a first balanced photoelectric detector, a second balanced photoelectric detector, a third balanced photoelectric detector and a polarization analysis module. According to the optical fiber vibration sensing system based on the polarization state and the application, the vibration monitoring performance and reliability in a long-distance and high-noise environment can be improved.

The invention relates to the technical field of laser ranging, in particular to a double-optical-comb hybrid ranging device which comprises a signal detection optical path system and a signal demodulation optical path system. Wherein the signal detection optical path system comprises a first optical frequency comb, a first optical isolator, a first optical collimator, a first beam splitter prism, a reference mirror, a Faraday rotator, a convergence mirror and a target reflector; the signal demodulation optical path system comprises a second optical frequency comb, a second optical isolator, a second optical collimator, a half-wave plate, a second beam splitter prism, a third beam splitter prism, a first polarization controller, a first photoelectric detector, a reflector, a polarization beam splitter prism, a second polarization controller and a second photoelectric detector. A third polarization controller; and a third photoelectric detector. According to the invention, three ranging technologies of asynchronous optical sampling ranging, multi-heterodyne interference ranging and synthetic wavelength ranging are fused, and the problem that a large ranging range and high ranging precision cannot be simultaneously considered in the ranging process is solved.

The invention discloses a multi-modulation-format vector signal modulator based on microwave photonics, and relates to the field of microwave photonics. Comprising an IQ quadrature modulation module, a continuous wave laser, a first power optical splitter, an optical carrier frequency generation module, a polarization beam combiner, an optical amplifier, a polarization beam splitter and a photoelectric balance detector module, the IQ quadrature modulation module comprises a double-parallel Mach-Zehnder modulator, a first forming filter, a second forming filter, a first attenuator, a second attenuator, a first direct current voltage stabilization source and a second direct current voltage stabilization source. According to the invention, the formed and filtered IQ baseband signal is input into the double-parallel Mach-Zehnder modulator for quadrature modulation, the IQ baseband signal and the other path of optical carrier signal subjected to differential MZM frequency multiplication are subjected to polarization beam combination, and then the signal is converted into a radio frequency signal through PD, so that the generation of a high-frequency-band and multi-modulation-format vector signal is realized, and the high-frequency-band multi-modulation-format vector signal is suitable for the fields of high-speed communication, photon radar and the like.

The invention discloses a grating displacement encoder grating spacing error in-situ detection and self-compensation method, and belongs to the technical field of optical measurement, and the method comprises the steps: generating elliptically polarized light, modulating the elliptically polarized light into S polarized light, reflecting the S polarized light through a polarization beam splitter, converting the S polarized light into circularly polarized light through a quarter-wave plate, and enabling the circularly polarized light to enter a diffraction grating ruler; the diffraction grating ruler diffracts incident light to form first-order diffraction light and second-order diffraction light; processing and interference detection are carried out on the first-order diffraction light, and precise displacement conversion is carried out in combination with the Doppler effect of grating displacement; constructing an auto-collimation angle detection sensing module by using second-order diffraction light, and converting the distance manufacturing deviation of diffraction gratings by detecting the tiny change of a diffraction angle; and compensating the displacement measurement error of the grating encoder in real time according to the real-time detection result of the grating spacing manufacturing deviation. According to the invention, the off-line detection time and cost of the grating are greatly saved.

The invention discloses a novel phi-OTDR (optical time domain reflectometry) system with low sampling rate requirement and polarization suppression, which belongs to the field of distributed optical fiber sensing and consists of a laser, three optical splitters, two acoustic optical modulators, three 3dB couplers, three balance detectors, a polarization controller, two polarization beam splitters, a data acquisition card and a computer. On the basis of a traditional phi-OTDR, a double-path AOM structure is introduced, and one path of optical signal is led out as a reference signal to participate in signal demodulation after light splitting and coupling, so that the requirement of a system on a DAQ sampling rate is reduced. And meanwhile, a polarization fading suppression structure is added in the system to adjust the optical signal, so that the output of two paths of cross-polarization signals is realized, and the influence of polarization fading is suppressed in combination with a phase optimal selection algorithm based on a time domain window. While the requirement of a traditional phi-OTDR system for the DAQ sampling rate is effectively reduced, the influence of polarization fading on phase extraction is suppressed, and the precision of system disturbance monitoring is improved.

The invention relates to a polarization correlation imaging scheme for extracting a target from objects which are made of the same material and have different roughness. The laser generates a Gaussian beam, and random speckles are generated through the rotary ground glass. A polarizer is placed behind the ground glass to control the polarization direction, and a beam splitter divides speckles into a test beam and a reference beam. The reference light beam is received by the CCD, and the test light beam is reflected after irradiating an object and is separated by the beam splitter. One beam of light is received by the barrel detector after passing through the + 45-degree polarizer, and the other beam of light is collected by the other two barrel detectors after passing through the polarization beam splitter. And the computer performs correlated imaging on the signals acquired by the barrel detector and the preset speckles. By modulating the polarization state of the light field and designing the receiving end, additional object surface polarization information is introduced, so that the system can extract a target from objects which are made of the same material and have different roughness, and the system has application value in a complex confrontation environment.

The multi-channel synchronous scanning optical detection system comprises a DIC light path, a PL light path, a DF light path, a bright field light source and a dark field light source. The DIC light path sequentially comprises a first camera, a polarizing beam splitter, a total reflective mirror, a DIC lens unit, a first dichroscope and a second dichroscope; the PL light path sequentially comprises a second dichroscope, a first dichroscope and a second camera; the DF light path sequentially comprises a second dichroscope and a third camera; the bright field light source irradiates the sample through part of the DIC light path; the dark-field light source directly irradiates the sample; in the working state, the sample reflects the light of the bright field light source, the reflected light returns along the DIC light path to form a first defect image, the sample receives the light of the dark field light source and excites fluorescent light, the fluorescent light forms a second defect image along the PL light path, and the light, reflected by the sample, of the dark field light source forms a third defect image along the DF light path. The multi-channel synchronous scanning optical detection system can simultaneously scan sample defects by multiple optical paths.

According to the single-fiber coupling type double-beam miniaturized high-sensitivity atom magnetometer device, pumping laser and detection laser are orthogonally coupled into a single polarization maintaining fiber through a polarization beam splitter, and miniaturization of a light source light path is achieved. Besides, the polarization maintaining optical fiber and the polarization beam splitter are adopted to combine and decouple the light beams, so that the problems that the miniaturization difficulty of the magnetometer probe is increased due to light guide of multiple collimating heads and extra noise is introduced by multiple optical fibers are avoided, and high sensitivity is realized in a small detection volume; and a great promotion effect is achieved in related detection application of high-density multi-atom magnetometer array type heart and brain magnetism.

The invention provides a distributed optical fiber sound wave sensing chip, system and method based on polarization state detection. The chip comprises an optical pulse source module, a first spot size converter, a second spot size converter and a high-speed polarization analysis module, the optical pulse source module generates pulse light and outputs the pulse light to the optical fiber circulator and the sensing optical fiber through the first spot size converter; the second spot size converter receives scattered light returned from the sensing optical fiber and the optical fiber circulator and inputs the scattered light into the high-speed polarization analysis module; the high-speed polarization analysis module comprises a polarization beam splitting rotator, four interference structures and six photoelectric sensors; the polarization beam splitting rotator divides the scattered light into a TE mode and a TM mode, rotates the TM mode to the corresponding TE mode and then outputs the scattered light through two output ports of the polarization beam splitting rotator; each output end of the polarization beam splitting rotator is connected to one photoelectric sensor and one input end of the four-way interference structure; the four-way interference structure is provided with four output ends which are respectively connected to the rest photoelectric sensors.

Disclosed is a linear array scanning Brillouin scattering elastic imaging device. In the device, a signal generating system consists of a narrow linewidth continuous wave laser, a half-wave plate, a beam expander, a Y-direction scanning galvanometer, a microlens array, a pinhole array filter, a first plano-convex lens, a polarization beam splitter, a quarter-wave plate and a microscope objective. A signal receiving system consists of a microscope objective, a quarter-wave plate, a polarization beam splitter and an eight-channel optical collimator array. Each channel of an eight-channel spectrometer consists of an optical collimator, a convex lens, a scanning Fabry-Perot interferometer, a photomultiplier tube and an eight-channel photon collection card.

The invention provides a 2-micron high-order Poincare sphere vector vortex ultrafast laser polarization detection method, which comprises the following steps of: performing out-cavity and out-cavity beam splitting on 2-micron high-order Poincare sphere vector vortex ultrafast laser through a beam splitting module, directly detecting light intensity spatial distribution by one beam, and dynamically regulating and controlling the out-cavity of a polarization state by the other beam after the other beam enters a polarization regulation and control module; the computer communicates with the ESP32 development board to control the hollow rotary displacement table to change the forward included angle between the fast axis and the x axis of the vortex quarter-wave plate so as to change the polarization state of incident light; through the ultrafast laser polarization beam splitter, the polarization state of passing light is limited, and horizontal line polarized light perpendicular to a beam splitting surface passes through the ultrafast laser polarization beam splitter; dynamically detecting real-time data of light intensity which is dynamically adjusted outside the cavity through the polarization regulation and control module each time through a light intensity detection module; and the polarization analysis module receives regulation and control parameters of the polarization regulation and control module and light intensity parameters of the power detection module, analyzes the polarization state of a light beam input into the system, and completes 2-micron high-order Poincare sphere vector vortex ultrafast laser polarization detection.

The invention discloses a green laser and a laser welding machine. The green laser comprises a pumping source, a first reflector, a laser crystal, a polarization beam splitter, a second reflector, a frequency doubling crystal, a telescope lens group and a spectroscope; the pumping source provides pulse pumping light; the laser crystal absorbs the pulse pump light to generate fundamental frequency laser in an infrared band, the fundamental frequency laser enters the polarization beam splitter and is split into P polarized light and S polarized light, the P polarized light is transmitted out of the resonant cavity, and the S polarized light is transmitted in the resonant cavity; and the telescope lens group converges the fundamental frequency laser to the frequency doubling crystal to generate frequency doubling laser of a green light wave band, and the frequency doubling laser is transmitted by the spectroscope and then is output. The green laser is used for spot welding of high-reflection materials such as copper and aluminum, the maximum single pulse energy can reach 5 J, the maximum peak power is 2 kW, the pulse width ranges from 0.05 ms to 5 ms, the problem of low absorption of the high-reflection materials to laser in the 1-micron wave band is solved, and the green laser is an edge tool for precise spot welding of the high-reflection materials.

An electro-optic receiver includes a polarization splitter and rotator (PSR) that directs incoming light having a first polarization through a first end of an optical waveguide, and that rotates incoming light from a second polarization to the first polarization to create polarization-rotated light that is directed to a second end of the optical waveguide. The incoming light of the first polarization and the polarization-rotated light travel through the optical waveguide in opposite directions. A plurality of ring resonators is optically coupled the optical waveguide. Each ring resonator is configured to operate at a respective resonant wavelength, such that the incoming light of the first polarization having the respective resonant wavelength optically couples into said ring resonator in a first propagation direction, and such that the polarization-rotated light having the respective resonant wavelength optically couples into said ring resonator in a second propagation direction opposite the first propagation direction.

The invention belongs to the technical field of polarization imaging, and relates to a Sagnac broadband linear polarization imaging structure which comprises a second plane mirror, a first polarization beam splitter, a first polarization analyzer, a first imaging lens and a first focal plane array which are sequentially arranged on a first optical axis at intervals. The compensation plate is arranged close to the second plane mirror; the first plane mirror and the first polarization beam splitter are arranged on a second optical axis perpendicular to the first optical axis in a spaced mode and located on the side away from the compensation plate; the first blazed grating and the second blazed grating are reversely arranged at intervals and located on the light path between the first plane mirror and the second plane mirror, and the first blazed grating is close to the first plane mirror. The system provided by the invention is small in adjustment workload, high in accuracy, sufficient in shearing amount compensation, and good in broadband polarization imaging image precision and overall stability.

The utility model relates to a device for measuring the three-dimensional shape of a sample with non-uniform reflectivity. The device comprises a structured light illumination element DLP, a collimating lens group, a polarizing beam splitter, a 1 / 4 wave plate, a motor, a dispersion tube lens, an objective lens, an objective table for placing the sample to be measured, a focusing lens, a dichroic mirror, a first optical filter, a first camera, a total reflection prism, a second optical filter, a second camera and a microprocessor, the 1 / 4 wave plate, the motor, the dispersion tube lens, the objective lens, the objective table, the focusing lens, the first camera and the second camera are perpendicular to the same optical axis, and the structured light illumination element DLP, the polaroid and the collimating lens group are parallel to the same optical axis and are perpendicular to the optical axis reflected by a tested sample. According to the utility model, the structure is simple, the first camera and the second camera can rapidly acquire images of two wavebands of a sample with non-uniform reflectivity based on the structured light illumination element DLP, and the microprocessor rapidly measures the height difference of the sample with non-uniform reflectivity based on the images of the two wavebands.

An assembly for coupling optical fibers to photonic ports on a surface of a photonic integrated circuits includes optical components for directing optical signals between a fiber array unit and the PIC, the optical components including a pair of lens arrays and a polarizing beam splitter. Non-polarization maintaining fibers may be used with the assembly.

The invention discloses a laser cavitation diagnosis device and method based on double-frame delay synchronous phase shift. The device comprises an excitation module and a detection module. The excitation module comprises a first laser, a first 1 / 2 wave plate, a polarization splitting prism, a spectroscope, an energy meter, a convex lens and a water tank; the detection module comprises a second laser, a beam expanding lens group, a second 1 / 2 wave plate, a second polarization splitting prism, a third 1 / 2 wave plate, a first reflector, a second reflector, a fourth 1 / 2 wave plate, a third polarization splitting prism, a third reflector, a fourth polarization splitting prism, a first 1 / 4 wave plate, a first imaging lens, a first micro-polarization camera, a second 1 / 4 wave plate and a second imaging lens; and a second micro-polarization camera. According to the invention, a double-frame delay method is introduced into traditional synchronous phase-shifting interference, the defects of the existing cavitation detection technology are overcome, and instantaneous phase change observation in a single cavitation pulsation period is realized.

According to the fiber-optic gyroscope for suppressing the relative intensity noise of the light source based on the double Y waveguides, interference signal light output by the same light source and noise polarization correlation of matched reference light are utilized, fine adjustment is carried out through the design of the two Y waveguides, so that the output intensity of the two Y waveguides is precisely consistent, polarization states are orthogonal, and the relative intensity noise of the gyroscope light source is suppressed; the precision of the gyroscope is improved; multiple polarization beam splitter assembly light paths are specially designed in a gyroscope light path, polarization state orthogonality and equal-light-intensity light splitting and light combination can be achieved, the specific use method of the gyroscope light path design is further provided, fiber-optic gyroscope homologous interference signal light and matched reference light can specifically meet the adjustment requirements, and the method is suitable for popularization and application. The light source relative intensity noise is effectively reduced, and the output signal-to-noise ratio is improved. The device is simple in design structure, low in implementation difficulty, capable of being finely adjusted, high in adaptability, good in noise suppression effect, suitable for single-axis and multi-axis fiber-optic gyroscopes and also suitable for other fiber-optic sensors with similar optical path structures.

The invention relates to the technical field of optical element surface shape dynamic measurement scheme design, in particular to an element surface shape dynamic measurement system based on a metasurface. According to the scheme, polarized light emitted by a laser is split into reference light and test light, the test light passes through a quarter-wave plate twice to realize polarization orthogonalization, and the test light is combined with the reference light to form elliptically polarized light; synchronously capturing component intensities of left-handed / right-handed circular polarized light and orthogonal line polarized light by using a detector, and resolving a phase difference delta in real time by combining a Stokes parameter; environmental interference is eliminated based on a common-path design, a polarization beam-splitting element is omitted, and the architecture is simplified; accurate dynamic measurement of the surface shape of the measured piece is realized by deducting the inherent surface shape error of the system. The system provided by the invention has the advantages of strong anti-interference performance, high measurement efficiency, remarkable cost reduction and the like, and is suitable for precise optical manufacturing and on-line detection scenes.

Disclosed are a self-adaptive all-fiber laser ultrasonic measuring instrument and a measuring method thereof. The output light of a narrow-linewidth semiconductor fiber laser is split by a polarization controller and a polarization beam splitter to generate detection light and reference light. The detection light and visible light output by an indication laser are irradiated, through a wavelength division multiplexer and a biaxial scanning galvanometer, to a sample under test to generate ultrasonic vibration. The scattered light modulated by the ultrasonic vibration is converged and collected as signal light. The signal light and the reference light are respectively input into an interferometer from two ends of the interferometer in opposite propagation directions. The reference light demodulated by the interferometer generates a feedback control signal for adjusting the measurement performance of the interferometer. The signal light demodulated by the interferometer generates an ultrasonic signal to achieve ultrasonic measurement of the sample.

The invention relates to the technical field of quantum measurement, and discloses a high-speed arbitrary adjustable unbiased generalized measurement device for light quantum polarization bits, and the device comprises a high-speed adjustable z-axis rotation device; a high-speed adjustable y-axis rotating device; a measurement intensity high-speed adjusting device; a sigma z basis vector projection measurement device; a unit measuring device; and an electronics post-processing module. According to the invention, sigma z base vector projection measurement is constructed through an optical fiber polarization beam splitter (FPBS), unit measurement is constructed through an optical fiber beam splitter (FBS), and sigma z base vector unbiased generalized measurement with high-speed adjustable measurement intensity is realized in combination with a measurement intensity high-speed adjusting device and an electronics post-processing module. And the rotation of the measurement basis vector on the Bloch ball is realized through the high-speed adjustable z-axis rotating device and the high-speed adjustable y-axis rotating device, so that the high-speed arbitrary adjustable unbiased generalized measurement is realized.

The embodiment of the invention provides a rubidium atomic clock based on a velocity grating spectrum and an implementation method, and the method comprises the steps: enabling a multi-frequency coherent laser source to emit a laser signal containing the velocity grating spectrum, and dividing the laser signal into two paths through a polarization splitting prism; the reflected light beam enters the laser frequency stabilization module to realize laser frequency stabilization; a transmission light beam enters the rubidium bubble through the lens group to interact with rubidium atoms; the photoelectric tube detects a transition spectral line, converts the transition spectral line from an optical signal into an electric signal and transmits the electric signal to the lock-in amplifier for demodulation; the integral amplification module converts the demodulated direct-current voltage into linear increasing voltage and transmits the linear increasing voltage to the crystal oscillator; the crystal oscillator generates an initial microwave signal and generates a microwave signal corresponding to the 87Rb atom through the frequency synthesizer; and the phase frequency modulation module modulates the microwave signal to obtain an error signal and transmits the error signal to the microwave resonant cavity so as to adjust the electromagnetic field according to the error signal to stably lock the rubidium atomic clock. The method is used for achieving the effect of improving the stability of the rubidium atomic clock system.

The invention discloses a quasi-distributed sensing system based on a fiber type auxiliary interferometer and vernier sensitization, and relates to the technical field of optical fiber sensing. The system comprises a data acquisition module, a to-be-detected sample parameter detection device and a data processing module, the to-be-detected sample parameter detection device comprises a plurality of FPI sensors; the data acquisition module is used for acquiring optical signals corresponding to parameters of a sample to be measured and comprises a tunable laser, a main interferometer, an auxiliary interferometer, a polarization beam splitter, a balanced photoelectric detector and a data acquisition card; the main interferometer is a Mach-Zehnder interferometer, the auxiliary interferometer comprises a section of delay optical fiber with a preset length and two reflecting surfaces, and the auxiliary interferometer is arranged on a reference arm of the Mach-Zehnder interferometer; and the data processing module is used for performing first processing and second processing on the optical signal output by the data acquisition module so as to obtain the variable quantity of the to-be-detected sample parameter. According to the invention, the technical bottlenecks of complex structure, difficult debugging, low demodulation efficiency and the like in the traditional scheme are effectively overcome.

In some implementations, an optical system for LIDAR sensing includes a transmitter configured to transmit a beam; a polarization beam splitter configured to block a first polarized transmission component of the beam and pass through a second polarized transmission component of the beam; a waveplate configured to convert the second polarized transmission component of the beam to a circular polarization state and to direct the beam toward a target, wherein the waveplate is configured to receive a return reflection of the beam and convert the return reflection to a second polarized reflection component, and wherein the polarization beam splitter is configured to reflect the second polarized reflection component and pass through a first polarized reflection component of the return reflection; a linear polarizer configured to pass through the second polarized reflection component; and a coherent receiver configured to receive the return reflection from the linear polarizer.

A zero-optical-path-difference double-frequency heterodyne grating ruler comprises a light source, a signal detecting and processing system, a polarization splitting prism, a first quarter-wave plate, a rectangular prism, a second quarter-wave plate, a third quarter-wave plate, a total reflection mirror, a long-strip prism, a reference grating and a 45-degree-placed polaroid. The two measuring light paths of the system always keep zero optical path difference, so that the measuring precision can be ensured, and the environmental stability of the system is also remarkably improved. And a high-precision and high-robustness measurement scheme is provided for precision equipment such as a photoetching machine and a precision motion platform.

The invention discloses a pattern wafer multi-parameter synchronous detection system and method based on double optical combs, and belongs to the field of wafer quality detection. The system comprises a signal light path, a reference light path, a detection light path and a synchronous detection module. After interference, the detection light beam and the reference light beam are decomposed into an H path and a V path through the polarization beam splitter, and are synchronously detected by the first camera and the second camera. The invention also provides a method which comprises the following steps: synchronously acquiring two paths of time domain interference data; fourier transform is carried out on each pixel point to obtain a plurality of spectrum pairs; the processing unit decodes in parallel based on the spectrum pair, and synchronously inverts multi-dimensional physical parameters such as three-dimensional morphology, stress and film parameters of the pattern wafer; and finally, comparing and identifying defects. According to the method, the problems of low detection efficiency and single information dimension in the prior art are solved, and wide-field, high-speed, high-precision and multi-parameter synchronous comprehensive characterization is realized.

The invention discloses an optical up-conversion, optical fiber transmission and self-interference elimination integrated device and method. The invention discloses an optical up-conversion, optical fiber transmission and self-interference elimination integrated device which comprises a central station, a transmission medium and a far-end base station. Wherein the central station comprises a first wavelength tunable laser (1), a local oscillator signal generator (2), a second wavelength tunable laser (3), a first double-parallel Mach-Zehnder modulator (4), an electric power divider (5), a second double-parallel Mach-Zehnder modulator (6), a 90-degree polarization rotator (7) and a polarization beam combiner (8). And a transmission medium adopts a single-mode optical fiber (9). The far-end base station comprises an optical power amplifier (10), a polarization beam splitter (11), a first photoelectric detector (12), a second photoelectric detector (13), an electric power amplifier (14), a transmitting antenna (15) and a receiving antenna (16). The invention further provides an optical up-conversion, optical fiber transmission and self-interference elimination method. According to the invention, the influence of the up-conversion transmission signal on the signal received by the far-end base station can be eliminated, the transmission quality of the received signal is improved, and the base station is simplified.