682 results about "Polarization controller" patented technology

The invention belongs to the technical field of retina imaging and fundus three-dimensional reconstruction, and particularly relates to a color three-dimensional fundus imager optical system. Comprising a large eye objective lens, a dichroscope, a hollow reflector, a focusing lens, a spectroscope, a retina lens, a retina imaging chip, a fixation lens, a sighting mark lamp, an illumination lens, an annular light source, a pupil lens, a pupil imaging chip, an infrared lens, an infrared dodging lens, an infrared light source, a scanning lens, a three-dimensional galvanometer, a collimator, a coupler, a frequency sweeping light source and a dispersion compensator. A polarization controller, a coupler and a photoelectric detector. The system is mainly composed of a visible light imaging light path, an infrared imaging light path and a laser imaging light path, the visible light imaging light path is used for shooting color fundus two-dimensional images, the infrared imaging light path is used for real-time positioning and focusing of human eye pupils, and the laser imaging light path is used for three-dimensional tomography of retinas. The objective of the invention is to solve the problem that existing medical equipment cannot acquire fundus color three-dimensional images.

The invention discloses a range gating anti-disturbance optical frequency domain reflection distributed measurement device and method. The device comprises a sweep frequency laser light source, a first optical coupler, a Mach-Zehnder modulator, a circulator, a detection optical fiber, a polarization controller, a second optical coupler, a balanced photoelectric detector and a data measurement unit. Wherein the Mach-Zehnder modulator is configured to perform BPSK modulation on the input probe light by using a pseudo-random spread spectrum coding technology. By means of the device and the method, the contradiction that long-distance measurement and fast frequency sweeping are difficult to achieve at the same time in a traditional OFDR is successfully solved.

The invention discloses an optical frequency comb generation method and device based on Brillouin scattering and an electro-optical modulator, and belongs to the field of photoelectric measurement. The method comprises the steps that a first laser and a second laser are used for generating pump light and seed light respectively, multi-wavelength pump light is generated through a cascade electro-optical modulator, the pump light and the seed light are emitted into a Sagnac loop, an optical frequency comb is output through the forward Brillouin scattering effect of an optical fiber and the electro-optical modulator, and the seed light and the pump light are output. The polarization controller is adjusted to optimize polarization state matching of the pump light and the seed light, so that the Brillouin scattering effect reaches the maximum value. The device is composed of a laser, an electro-optical modulator, a signal generator, an optical amplifier, an optical isolator, an optical coupler, a polarization controller and an optical fiber. The optical fiber forward Brillouin scattering effect and the electro-optical modulator are combined, the optical frequency comb giving consideration to the wide frequency spectrum and the narrow interval is generated, meanwhile, the comb tooth interval of the optical frequency comb can be accurately controlled by independently adjusting the frequency of the signal generator, and accurate measurement of signals or objects is achieved.

The invention relates to an optical acoustic sensor, in particular to a high-sensitivity acoustic sensor based on Fano resonance and a measuring method. The problem that an existing optical acoustic sensor is low in sensitivity is solved. A high-sensitivity acoustic sensor based on Fano resonance comprises a 1550nm laser, a phase modulator, a first polarization controller, a conical optical fiber, a CaF2 crystal resonant cavity, a second polarization controller, a photoelectric detector, an oscilloscope and a computer. The emergent end of the 1550nm laser is connected with the head end of the conical optical fiber through the phase modulator and the first polarization controller in sequence; the conical optical fiber is coupled with the CaF2 crystal resonant cavity; the tail end of the conical optical fiber is connected with the incident end of the photoelectric detector through the second polarization controller; the signal output end of the photoelectric detector is connected with the signal input end of the oscilloscope; the signal output end of the oscilloscope is connected with the signal input end of the computer. The method is suitable for acoustic signal measurement in the fields of industry, traffic, environmental protection, medical treatment and the like.

The invention discloses a jitter calibration system and method for a superconducting nanowire single-photon detector. Comprising an FPGA platform used for generating periodic pulse calibration signals, a radio frequency pulse amplifier, a lithium niobate electrooptical modulator and a bias voltage controller thereof, a 1550nm 3kHz linewidth distributed feedback laser, a program control optical attenuator, a three-paddle polarization controller, an SNSPD single photon detector, a multichannel TDC module and an upper computer used for processing data. The calibration method is simple and low in cost, can calibrate a correction curve of the relation between SNSPD detection photon additional jitter and detection recovery time caused by pulse accumulation, compensates additional jitter, and can effectively solve the problem of jitter deterioration generated by SNSPD under a high counting rate in high-speed detection application.

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 provides a diaphragm type optical fiber liquid level sensing demodulation device and method based on a microwave photon technology, and the device comprises a broadband light source, a circulator, a diaphragm type optical fiber liquid level sensor, an erbium-doped optical fiber amplifier, a polarization controller, a DC power supply, a radio frequency source, an electro-optical modulator, a dispersion compensation optical fiber, a photoelectric detector and a power meter. The broadband light source is connected with a first port of the circulator, a second port of the circulator is connected with the diaphragm type optical fiber liquid level sensor, a third port of the circulator is connected with the erbium-doped optical fiber amplifier, the erbium-doped optical fiber amplifier is connected with the polarization controller, and the polarization controller is connected with the input end of the electrooptical modulator. The radio frequency source is connected with the modulation input of the electro-optical modulator, the direct current power supply is connected with the bias voltage input of the electro-optical modulator, the output of the electro-optical modulator is connected with the photoelectric detector through the dispersion compensation optical fiber, and the photoelectric detector is connected with the power meter, so that the measurement range is expanded while the sensing sensitivity and the resolution ratio are improved.

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 discloses a high-tolerance synchronous dual-band pulse laser, and relates to the field of lasers, and the laser comprises a first resonant cavity and a second resonant cavity; the first resonant cavity comprises a first pumping source and an optical annular cavity formed by sequentially connecting a first wavelength division multiplexer, a first thulium-doped optical fiber, a first optical coupler, a first isolator, a second wavelength division multiplexer, a high-nonlinearity saturable absorber, a third wavelength division multiplexer and a first polarization controller; the second resonant cavity comprises a second pumping source and an optical annular cavity which is formed by sequentially connecting a fifth wavelength division multiplexer, a second erbium-doped fiber, a second optical coupler, a second wavelength division multiplexer, a high-nonlinearity saturable absorber, a third wavelength division multiplexer, an electric control adjustable delay line, a fourth wavelength division multiplexer, a second polarization controller and a second isolator, and the fifth wavelength division multiplexer, the second erbium-doped fiber, the second optical coupler, the high-nonlinearity saturable absorber, the third wavelength division multiplexer, the electric control adjustable delay line, the fourth wavelength division multiplexer, the second polarization controller and the second isolator; and the first optical coupler and the second optical coupler respectively output synchronization pulses in the wave bands of 2 microns and 1.5 microns. The device is compact in structure, low in manufacturing cost, convenient to operate and capable of covering the mid-infrared band of 2 microns.

An optical frequency domain reflectometer with environmental disturbance resistance and large strain measurement capability belongs to the field of distributed optical fiber sensing and comprises an opposite sweep frequency light frequency modulation continuous wave signal generation module, a light splitting device, a modulation device, a circulator, a polarization controller, an optical coupling device, a photoelectric conversion module and a data acquisition and processing module. An optical signal generated by an opposite sweep frequency light frequency modulation continuous wave signal generation module is divided into probe light and local oscillation light through a light splitting device, the probe light is modulated through a modulation device and sent to an optical fiber through a circulator, and a Rayleigh back scattering light signal generated by the optical fiber and the local oscillation light interfere in an optical coupling device to obtain interference light; the photoelectric conversion module mixes beat frequency signals of interference light, and the data acquisition and processing module analyzes and processes the beat frequency signals. According to the invention, the position information of the Rayleigh backscattering point is marked by using the modulated probe light, the Rayleigh scattering signal at the corresponding position is restored, crosstalk between channels is inhibited, and high-precision measurement in a large dynamic range and resistant to environmental disturbance is realized.

The invention discloses a method and device for monitoring settlement and convergence of tunnel surrounding rock. The method comprises the following steps that optical fiber sensing chains are installed in the circumferential direction of a tunnel; the tunable laser emits frequency sweeping light with continuous wavelength and then the frequency sweeping light is divided into two parts through the coupler A; after one part of light enters a coupler D, signals are transmitted to a first photoelectric detector; the other part of the light enters a coupler B, and after the light is split by the coupler B, one part of the light enters a polarization controller of the reference light path, and the other part of the light enters a measuring light path of the optical fiber sensing chain; optical signals in the reference optical path and the measurement optical path are subjected to beat frequency interference and are received by a balanced photoelectric detector; data of the first photodetector and the balanced photodetector are acquired. The optical fiber sensing chain is installed along the tunnel in the circumferential direction, tunnel deformation is monitored through an OFDR distributed optical fiber sensing system, overall deformation of a protection material is reconstructed through obtained distributed strain data, and an effective means is provided for large-range measurement of deformation fields such as a tunnel face.

The utility model relates to a high-capacity wavelength division multiplexing fiber bragg grating sensing system in the field of fiber sensing. The high-capacity wavelength division multiplexing fiber bragg grating sensing system comprises a mode-locked fiber laser, a spectrum expansion module, a three-port optical circulator, a fiber bragg grating array, a dispersion module, a photoelectric detector, a data acquisition module and a data processing module. The spectrum expansion module is composed of an optical fiber amplifier, a nonlinear element and a polarization controller; the optical fiber amplifier is composed of an optical isolator, an erbium-doped optical fiber, a wavelength division multiplexer and a pump light source. According to the sensing system, the dispersion Fourier transform technology is applied, the offset of the center wavelength of the fiber bragg grating is mapped into the offset of time delay between time domain reflected light pulses, and the demodulation rate and precision of the fiber bragg grating sensing system are improved; and by adding a spectrum expansion module, the spectrum of pulse data output by the light source laser is expanded into a super-continuum spectrum by using a nonlinear effect, and the simultaneous measurement of hundreds of fiber bragg grating sensors can be theoretically supported.

The invention discloses a guided-mode resonance refractive index detection device and method based on a longitudinal gradient grating structure, and belongs to the technical field of optical sensing and imaging spectrum detection, the guided-mode resonance refractive index detection device comprises a light source, an optical isolator, a polarization controller, a collimation beam expander, a guided-mode resonance sensing chip, an image detector and a signal processing unit which are connected in sequence; the guided-mode resonance sensing chip is of a transmission type structure, the top of the guided-mode resonance sensing chip is provided with a strip-shaped nano structure which is consistent in period but longitudinally gradually changed, and an image detector is arranged below the guided-mode resonance sensing chip and used for receiving a transmission light signal penetrating through the guided-mode resonance sensing chip, generating a transmission light image and transmitting the transmission light image to the signal processing unit; and the signal processing unit is used for analyzing the transmitted light image and inverting the refractive index of the medium to be measured according to the structure mapping model. According to the invention, the longitudinal structure gradual change characteristic is introduced into the guided-mode resonance chip, so that the spatial distribution control of the monochromatic light resonance response position is realized, and finally the imaging refractive index sensing without an optical splitter is realized.

The utility model discloses a high-order transverse mode controllable space-time mode locking all-fiber laser, which relates to the field of fiber lasers and comprises an annular laser system and a feedback system. The ring laser system comprises a laser diode pumping source, a wavelength division multiplexer, a gain fiber, a high-order transverse mode generation module, a multi-mode output coupler, a saturable absorber, a polarization controller, an isolator and an out-of-cavity coupler. The feedback control system comprises an image acquisition module, an image processing module and a feedback control circuit. Space-time mode locking is achieved based on the all-fiber saturable absorber, and the device has the advantages of being simple in structure, small in environmental influence, good in stability and the like. By inserting the multi-core multimode optical fiber and the conical multimode optical fiber into the all-fiber mode-locked laser, excitation of a high-order transverse mode and screening of the high-order transverse mode are effectively achieved. By externally connecting a feedback control system, the high-order transverse mode output by the laser is selected, and the space-time mode-locked all-fiber laser with controllable output high-order transverse mode is effectively realized.

The invention discloses a vector flow velocity measuring device and method based on a bidirectional scanning spectral domain optical coherence tomography technology. Comprising a super light-emitting diode light source, an optical fiber coupler, a polarization controller, an interferometer comprising a sample arm and a reference arm, and a collimating lens, the collimating lens, the grating, the focusing lens group and the linear array camera are sequentially connected through a light path; the linear array camera, the computer and the two-dimensional galvanometer are sequentially connected through a line; according to the method, the fixed bias vector velocity is introduced by utilizing the bidirectional scanning technology, the dynamic light scattering optical coherence tomography method and the Doppler optical coherence tomography method are combined, decoupling of each parameter of the vector flow velocity is efficiently and accurately realized, and a quantitative index is provided for vector flow velocity analysis. The vector flow velocity measuring device based on the bidirectional scanning spectral domain optical coherence tomography technology is simple in system setting and low in cost, the time resolution is improved by about 2.5 times, and the measuring time is shorter.

The invention discloses a narrow linewidth optical fiber laser system based on a self-injection locking feedback mechanism, which belongs to the field of optical fiber communication and comprises a main cavity, a self-injection locking feedback module and an erbium-doped optical fiber amplifier. Wherein the main cavity internally comprises a composite ring cavity filter for selecting a longitudinal mode; the composite ring cavity filter is sequentially connected with a polarization controller, a first erbium-doped fiber, a first wavelength division multiplexer, a second erbium-doped fiber and a first uniform fiber bragg grating through a first circulator; the output end of the first uniform fiber bragg grating is connected with the input end of a first optical fiber coupler, one output end of the first optical fiber coupler is sequentially connected with an optical fiber delay line and a Faraday rotating mirror in the self-injection locking feedback module, and the rotating angle of the Faraday rotating mirror is 90 degrees; and the other output end of the first optical fiber coupler is connected with the input end of the erbium-doped optical fiber amplifier. Through the above structure, the stability of the laser system is improved.

The invention relates to the technical field of optical fiber sensing, in particular to an optical fiber sensor system, a sensing signal measuring method, computer equipment and a medium. The optical fiber coupler comprises at least two optical fiber interference arms which are arranged in parallel and is used for dividing an optical signal into at least two beams and enabling the beams to be propagated along different paths to generate interference; the polarization controller is arranged at the emergent end of the optical fiber coupler and is used for regulating and controlling the polarization state and the polarization direction of the emergent light; the voltage control module is arranged on at least one optical fiber interference arm and used for changing the phase of the optical fiber by applying voltage; the image sensor is used for collecting interference fringe images and converting the interference fringe images into electric signals; and the data processing device is used for carrying out peak searching calculation on the electric signal to obtain stripe movement information, and obtaining a corresponding sensing signal value according to the relationship between the stripe movement information and the sensing signal. The application range of the interferometer in the visible light wave band is expanded, and the measurement precision of the interferometer is improved.

The invention discloses a TGD-OFDR / OCC-BOTDR integrated multi-parameter sensing system and a working method thereof, and relates to the technical field of optical fiber sensors. The multi-parameter sensing system comprises a laser, an optical fiber coupler, an electro-optical modulator, an optical fiber circulator, an optical fiber Bragg grating, an acoustic optical modulator, an erbium-doped optical fiber amplifier, a random scrambler, a piezoelectric ceramic tube, a heating vessel, a delay optical fiber, a photoelectric balance detector, a filter and detector, a data acquisition card, a polarization controller, a direct-current power supply and a microwave source. An arbitrary waveform generator and the like. According to the invention, multiple parameters can be represented at the same time, the measuring speed is fast, and the sampling rate of the system can be effectively improved under the condition that sensing parameters are the same; the method has the advantage of high spatial resolution; the sensor has the advantages of high fusion and low cost, can realize simultaneous measurement of vibration and temperature / strain through single sensing, and is high in fusion and effective in cost control.

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 discloses a light field regulation and control system and method based on laser array coherent combination. A laser array generation module is used for outputting a high-power array light beam; a spatial beam-shrinking light path in the light field regulation and control module samples an array light beam and carries out beam-shrinking processing, so that the light field area of the array light beam after beam-shrinking can be matched with the effective target surface size of spatial light modulators, and the two spatial light modulators respectively regulate and control the phase and polarization of two cross-polarization components of the array light beam after beam-shrinking. The regulated light beam is transmitted to a phase and polarization locking loop; and the phase and polarization locking loop generates a phase control signal and a polarization control signal according to the regulated light beam output by the light field regulation module, and applies the phase control signal and the polarization control signal to a phase modulator and a polarization controller of each path of unit laser in the laser array generation module, so that phase and polarization locking of the high-power array light beam is realized. According to the invention, flexible light field regulation and control of far-field synthetic light spots of the array light beams can be realized.

The invention relates to a tunable microwave pulse generation system and method based on injection locking, and belongs to the technical field of microwave photon signal generation and processing. The system comprises a laser, a polarization controller, a closed-loop optoelectronic oscillator (OEO) loop and two microwave sources, wherein the closed-loop optoelectronic oscillator (OEO) loop is composed of a double-parallel Mach-Zehnder modulator, a single-mode optical fiber, an optical tunable delay line (OTDL), a photoelectric detector, a broadband band-pass filter, an electric amplifier, a power divider and a coupler which are connected in sequence.

The invention belongs to the technical field of lasers, and discloses a fiber laser for promoting generation of a stable soliton attraction state by using a high-birefringence fiber. The optical fiber laser comprises a laser pumping source, a wavelength division multiplexer, an erbium-doped gain optical fiber, a polarization independent isolator, a polarization controller, a polarization maintaining optical fiber, an output coupler and a mode locking device based on a carbon nanotube saturable absorber, and all the components are sequentially connected through single-mode optical fibers. The polarization-maintaining optical fiber is a panda-shaped polarization-maintaining optical fiber with a high birefringence effect. The polarization direction and the polarization state in the cavity are accurately controlled by adjusting the polarization controller, phase synchronization of soliton pulses is achieved when the polarization maintaining optical fiber is output, soliton energy in the cavity is rapidly accumulated, soliton splitting is triggered, and finally a stable multi-pulse soliton attraction state is formed. The design is simple and convenient to operate, and stability and anti-interference capability of soliton transmission are remarkably improved.

The utility model discloses a distributed sound wave sensing system for multi-frequency pulse modulation, and relates to the technical field of distributed sound wave sensing. The system comprises a narrow linewidth laser, an optical fiber coupler, a polarization-maintaining optical isolator, an acousto-optic modulator, a polarization-maintaining delay optical fiber, an erbium-doped optical fiber amplifier, a polarization-maintaining dense wavelength division multiplexer, an optical fiber circulator, an optical fiber Bragg grating, a piezoelectric transducer, a polarization controller, a photoelectric balance detector, a data acquisition card, an arbitrary waveform generator and the like. According to the utility model, the multi-frequency delay ring is utilized to carry out multi-frequency modulation, the frequency number of light waves is increased along with the circulation times of the light waves in the delay ring, and under the condition that the utilization of a large-bandwidth electro-optical modulator is not increased, the flexible modulation of the frequency is realized by utilizing a low-bandwidth acousto-optical modulator without being influenced by carrier frequency and sidebands of each order; the low-bandwidth acousto-optic modulator is used for frequency modulation in the multi-frequency delay ring, and compared with an electro-optical modulation or multi-acousto-optic / multi-light source modulation scheme, the modulation cost is effectively saved.

The invention discloses a modulation device with an adjustable splitting ratio. The modulation device comprises a polarization controller, two Mach-Zehnder interferometers, a polarization rotation beam combiner and an end face coupler, wherein the two output ends of the polarization controller are respectively connected with the input ends of the two Mach-Zehnder interferometers; one output end of each Mach-Zehnder interferometer is connected with the input end of the polarization rotation beam combiner; the output end of the polarization rotation beam combiner is connected with the input end of the end face coupler. The embodiment of the invention can realize any splitting ratio adjustment in a large range, and can be widely applied to the technical field of optical devices.

The invention discloses a periodic forked near-transformation limit nanosecond pulse mode-locked fiber laser and a generation method. The laser is characterized in that a fiber ring cavity comprises a wavelength division multiplexer, an erbium-doped fiber, a first polarization controller, a polarization analyzer, a dispersion control unit, an output coupler, a fiber isolator and a second polarization controller which are sequentially connected in a closed loop mode. The method comprises the steps that pumping continuous light is coupled into the laser through the wavelength division multiplexer; pumping continuous light is absorbed by using an erbium-doped fiber and is stimulated to radiate a gain pulse with a long wave band, and the generated pulse oscillates in a fiber laser cavity; under the combined action of a first polarization controller, an analyzer and a second polarization controller, an equivalent saturated absorption effect is generated by utilizing nonlinear polarization rotation generated when gain pulses are propagated in an optical fiber, and pulse mode locking is realized; the optical fiber laser works in an abnormal dispersion region, so that generated pulses meet the soliton area theorem, and near-transformation limit pulses are generated. According to the invention, nanosecond pulse period bifurcation output of the short-cavity fiber laser can be realized.

The invention discloses a multi-parameter parallel detection method based on a single whispering gallery optical microcavity, which belongs to the field of whispering gallery microcavities; the method comprises: the two ends of an optical polarization controller are respectively connected to a laser and a whispering gallery microcavity sensor, the whispering gallery microcavity sensor is connected to multiple target parameter information disturbance devices, and a photodetector; the laser outputs an optical signal, which is adjusted to the maximum coupling efficiency by the optical polarization controller and then output to the whispering gallery microcavity sensor, and the target parameter information disturbance device is adjusted to disturb the optical signal by the target parameter, and the disturbed optical signal is output to an oscilloscope through the photodetector, which is reflected as n resonance mode offsets, and the changes of n target parameters are calculated by a signal processing method combining n offsets with an n-order sensor matrix, thereby realizing the multi-parameter parallel detection of the whispering gallery optical microcavity. The invention can realize high-precision decoupling and parallel detection of multiple parameters.

A quantum key distribution system is provided, including: a sending terminal, a measurement terminal, a receiving terminal, and at least one polarization controller. The sending terminal is configured to generate a quantum optical signal and receive a detection result. The measurement terminal includes a beam splitter and two single-photon detectors, the beam splitter is configured to generate two measurement optical signals based on the quantum optical signal, and the two single-photon detectors are configured to generate the detection result. The receiving terminal is configured to receive the detection result. The at least one polarization controller is provided in the sending terminal, the measurement terminal or the receiving terminal, and performs a polarization processing on the quantum optical signal or the detection result using a target transmittance matrix determined based on the detection result, so as to obtain a polarized quantum optical signal or a polarized detection result.

The invention discloses a confocal full-Mueller matrix imaging device and method based on an optical fiber metasurface array, and belongs to the technical field of polarized optical imaging. The device comprises an optical fiber array multi-polarization illumination module, a sample scanning module, a scattered light transmission module, a metasurface array polarization modulation module and a polarized light intensity detection module. The polarization states of four beams of light are regulated and controlled through the optical fiber polarization controller, and four illumination focal spots in different polarization states are generated on a sample plane at the same time; sample scattered light is modulated by a polarization measurement metasurface array comprising four independent metasurface units, and the polarization state of each path of optical signals is projected to sixteen polarized light spots which are spatially separated; and finally, acquiring light spot intensity information by an area array detector, and reconstructing a full-Mueller matrix image of the sample through calculation. According to the invention, full-Mueller matrix information can be obtained through single scanning, and the device has the characteristics of high resolution, compact structure, good compatibility and the like, and can be used for multi-dimensional polarization microscopic analysis of samples.

The invention discloses a symmetric low-noise Sagnac interferometer based on wavelength division multiplexing, and is applied to the field of non-contact ultrasonic detection. The all-fiber non-contact ultrasonic detection light path comprises a communication waveband broadband light source, a first polarization controller, a non-polarization-maintaining circulator, a first wavelength division multiplexer, a first polarization beam splitter, a second polarization beam splitter, a third polarization beam splitter, a second polarization controller, a non-polarization-maintaining long fiber ring, a fourth polarization beam splitter and a fifth polarization beam splitter. The device comprises a first polarization beam splitter, a sixth polarization beam splitter, a second wavelength division multiplexer, a polarization maintaining fiber focus lens, a 1 / 4 slide, a third polarization controller, a seventh polarization beam splitter and a balance detector. By combining wavelength division multiplexing, controlling multiple paths of different interference light to keep orthogonal high-symmetry design and using a balance detector to carry out differential detection, an extremely low detection noise level can be kept while pi / 2 phase bias and maximum fringe contrast are realized, and high-sensitivity non-contact ultrasonic detection is further realized.

The invention discloses a dual-wavelength mode-locked laser generating device and a dual-wavelength mode-locked laser generating method, and belongs to the technical field of optical communication, and the dual-wavelength mode-locked laser generating device comprises a pumping source, an optical integration module, a gain optical fiber, a saturable absorber and a dual-wavelength pulse independent polarization mode linear coupling regulation and control structure, linear coupling strength of cross-polarization components in two wavelength pulses is independently regulated and controlled by using a structure of a polarization controller and a polarization maintaining optical fiber, and dual-wavelength mode-locked pulse laser of different types of pulse combinations can be obtained. The coherent pulse light source with unique spectral characteristics can provide a low-cost light source for the fields of high repetition frequency optical combs, all-fiber architecture high repetition frequency soliton sequences and microwave photonics.