6512 results about "Beam splitters" 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 discloses a continuous zooming laser interference end point detection system, which is used for semiconductor etching and thin film process end point detection, and comprises an illumination module, a laser interference module and an imaging module, the laser interference module comprises a laser, a beam splitter, a beam splitting cube, a lens and a detector, a laser beam emitted by the laser passes through the beam splitter, the beam splitting cube and the lens and then is focused to a to-be-detected area on the surface of a wafer, and the surface of the wafer reflects the laser to the detector for detection; the focal length of the lens is continuously adjustable; the illumination module comprises a light source which is arranged on one side of the lens, and an illumination light beam emitted by the light source is used for illuminating a to-be-detected area on the surface of the wafer; and the imaging module comprises a camera which is arranged on one side of the lens and is used for recording and outputting image information of a to-be-detected area on the surface of the wafer. According to the invention, through continuous zooming and large numerical aperture of the lens, high-definition imaging and etching of a long working distance and accurate detection of a thin film process end point are realized.

The invention discloses an inter-satellite laser communication load on-orbit receiving and transmitting optical axis coaxial self-calibration device and method, and belongs to the field of inter-satellite laser communication. Comprising a cube-corner prism, a coarse pointing mechanism, a beam expanding group lens, a color separation sheet, a fast reflecting mirror, a communication signal light emitting system, an optical filter, a light splitting sheet, an optical filter, a signal focusing mirror, a communication signal detector, a tracking focusing mirror and a tracking signal detector. Under the condition that beacon light is not used and a laser source is not additionally added, communication signal light is directly adopted to calculate and compensate the offset between the receiving optical axis and the transmitting optical axis through the cube-corner prism, the on-orbit alignment capture time is greatly shortened, and the cost, power consumption, size and weight of a self-calibration device are reduced.

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 relates to a compact polarization rotation beam splitter, which comprises an input waveguide, a mode conversion region, a mode coupling region and an output waveguide, a TM0 mode optical signal in the optical signals is converted into a TE mode high-order optical signal in the mode conversion area; the mode coupling region is used for coupling the TE mode high-order optical signal into a TE0 mode optical signal with the first adiabatic coupling waveguide; and the output waveguide is used for outputting a TE0 mode optical signal which is not subjected to mode conversion in the optical signals, and outputting a TE0 mode optical signal obtained after mode conversion of the mode conversion area and the second adiabatic coupling waveguide. According to the invention, the polarization rotation path can be shortened through high-order mode conversion in the mode conversion area, efficient beam splitting is realized by using the asymmetric adiabatic coupling waveguide in the mode coupling area, the size reduction of a redundant structure is avoided through function integration, the performance of the beam splitter is ensured, and the problems of large size and low cost of the existing polarization rotation beam splitter are solved. And the performance is not good.

The invention relates to the field of laser powder bed melting monitoring technology and laser spectrum detection, in particular to an LIBS (laser-induced breakdown spectroscopy) detection device and method for online monitoring nitrogen, hydrogen and oxygen elements in stainless steel prepared by LPBF (laser PBF), and the LIBS detection device comprises an LPBF printing unit, an LPBF laser unit, an LIBS element detection unit and a calculation control unit; the LIBS element detection unit generates pulse laser by using an Nd: YAG laser, guides the laser beam to the surface of a stainless steel sample through a beam splitter and a galvanometer, excites and generates plasma, acquires a plasma spectrum through a six-channel optical fiber spectrometer, controls the time sequence of laser emission and spectrum acquisition, and analyzes spectral data in real time; the concentration distribution of nitrogen, hydrogen and oxygen elements in the sample is detected, the printing parameters of the LPBF laser unit are dynamically adjusted according to the analysis result, and rapid and real-time online detection of the nitrogen, hydrogen and oxygen elements in the stainless steel sample in the printing process is achieved.

The invention relates to the technical field of optics, in particular to a gas concentration regulation and control interference imaging system applied to shape righting of a nozzle handle, a shape righting tool and a nozzle are prepared, the shape righting tool is provided with a downward pressing mechanism, the downward pressing mechanism is provided with a downward pressing telescopic column for correcting the nozzle handle, and a displacement measurement interferometer system is assembled on the shape righting tool; the displacement measurement interferometer system is provided with a reflecting movable mirror and a beam splitter, and the reflecting movable mirror is mounted on the pressing telescopic column; the displacement measurement interferometer system further comprises an interference light path stroke difference fine tuning system. The interference light path stroke difference fine adjustment system comprises a glass container for containing sulfur hexafluoride, the end faces of the two ends of the glass container are flat and transparent, the glass container is arranged on a light path between the beam splitter and the reflective moving mirror, and the end faces of the two ends of the glass container are perpendicular to laser on the light path; the glass container is provided with an air supply port; the air supply port is connected to an air pump, and the air pump is connected with a sulfur hexafluoride air source. And the shape correcting position of the nozzle handle is accurately controlled.

The invention provides a frequency-modulated continuous wave laser ranging device based on frequency shift double optical combs, which integrates frequency-modulated continuous wave and double optical comb technologies and comprises an FMCW light source, a beam splitter, a detection and reference light channel, a beam combiner, a photoelectric detector and a processing module. The FMCW light source outputs linear frequency sweeping laser which is divided into two paths through the beam splitter, and the detection light channel detects a target through the first optical comb generator and the circulator. The frequency fFS of the reference optical channel is increased through a frequency shifter, optical combs with different comb tooth intervals are generated by a second optical comb generator, and the fFS and the repetition frequency difference delta fR are in a non-integer multiple relation, so that interference is effectively avoided. After being combined by the beam combiner, the two paths of signals are converted into beat frequency signals by the photoelectric detector, and then time domain signals are spliced by the processing module by using coherence, so that the distance measurement precision is improved. According to the invention, the frequency shift double-optical comb technology improves the precision and anti-interference performance; an efficient data processing algorithm ensures rapid measurement and a wide range of application.

The invention relates to the technical field of satellite laser communication, and discloses a laser communication double-end on-orbit calibration system and method, and the system comprises an A end and a B end which are in communication connection and have the same structure; the end B is a second laser communication terminal; the A end is a first laser communication terminal which comprises a main light path, and a transmitting branch, a receiving branch, a tracking branch and a calibration branch which are connected with the main light path; the main light path is composed of an A-end optical antenna, an A-end reflex reflector, an A-end fine tracking galvanometer, an A-end first spectroscope, an A-end second spectroscope, an A-end third spectroscope and an A-end emission galvanometer which are connected in sequence; the transmitting branch is connected with the A-end transmitting galvanometer; the receiving branch is connected with the A-end third spectroscope; the calibration branch is connected with the A-end second spectroscope; and the tracking branch is connected with the A-end first spectroscope. According to the invention, on-orbit receiving and transmitting coaxial calibration is carried out, calibration is carried out without the help of a ground end, and the efficiency is improved.

The present disclosure relates to an active graded magnetic compensation system and method for an unshielded SERF magnetometer. The system comprises: a detection laser, a half-wave plate, a magnetic field compensation coil, a magnetic field modulation coil, a non-magnetic heating assembly, an alkali-metal atomic vapor cell, a polarizing beam splitter prism, a balanced photodetector, a graded feedback control module, a pump laser, a quarter-wave plate, a focusing lens and a photodetector. By means of the present disclosure, a graded compensation system is used to realize high-precision compensation for a magnetic field within a large dynamic range in a geomagnetic environment, thereby ensuring that an instrument carries out high-sensitivity magnetic field measurement under geomagnetic conditions.

A method of reducing optical artifacts includes injecting a light beam generated by an illumination source into a polarizing beam splitter (PBS), reflecting a spatially defined portion of the light beam from a display panel, reflecting, at an interface in the PBS, the spatially defined portion of the light beam towards a projector lens, passing at least a portion of the spatially defined portion of the light beam through a circular polarizer disposed between the PBS and the projector lens, reflecting, by one or more elements of the projector lens, a return portion of the spatially defined portion of the light beam, and attenuating, at the circular polarizer, the return portion of the spatially defined portion of the light beam.

The invention discloses a lunar resource in-situ exploration-while-drilling device and method. The lunar resource in-situ exploration-while-drilling device is composed of a spiral drilling tool, an illumination light source module, a polarization spectrum detection module and a dual-channel spectrum measurement module. The drilling tool drill rod is of a hollow structure. Light emitted by the illumination light source module is collimated and depolarized to form unpolarized parallel light to irradiate lunar soil on the side wall of the drill hole, and the polarization spectrum measurement probe collects reflected light of the lunar soil; the reflected light is collimated by a front collimator objective of the probe and then sequentially passes through a spectrum modulation unit consisting of an achromatic 1 / 4 wave plate, a multi-stage wave plate, a beam splitter prism and two polaroids of which the light transmission directions are vertical to each other, and two orthogonal light beams are formed, so that polarization information of the reflected light is modulated in a spectrum dimension; demodulating the modulated spectrum to obtain the spectrum and polarization information of the lunar soil reflected light; and the resource distribution and content and the physical characteristics of the original lunar soil are inversed by using the polarization spectrum characteristics of the lunar soil. According to the invention, in-situ exploration of lunar subsurface depth profile mineral resources can be realized.

The embodiment of the invention provides an eyepiece system and optical equipment. The eyepiece system comprises a first element group and a second element group; the first element group is arranged close to the human eye side and comprises a first lens, the first lens is provided with a first surface close to the display side and a second surface close to the human eye side, the first surface is provided with a light splitting element and a circularly polarized light generation assembly, and the circularly polarized light generation assembly is located on the side, away from the first lens, of the light splitting element; a first phase retarder and a polarization reflection element are sequentially arranged on the second surface; the second element group is arranged close to the display side and comprises at least two lenses, and the Abbe number of at least one lens is less than or equal to 40; the eyepiece system satisfies the following conditions: 0.01 < = (D1max * phi1) / (D2max * phi2) < = 0.3; wherein phi 1 is the focal power of the first element group, phi 2 is the focal power of the second element group, D1 is the maximum effective optical aperture of the first element group, and D2 is the maximum effective optical aperture of the second element group.

The invention discloses a three-band common-caliber multifunctional optical system. Belongs to the technical field of optical imaging and particularly relates to the technical field of multiband common-aperture optical systems. The problem that integration, multi-functionalization and miniaturization cannot be achieved at the same time through an existing multi-band common-caliber optical system is solved. The three-band common-caliber multifunctional optical system comprises a primary mirror L1, a secondary mirror L2, a multi-band compensation mirror group L3, a first reflecting mirror L4, a first spectroscope L5, a second reflecting mirror L6, a medium-wave infrared mirror group L7, a third reflecting mirror L8, a laser and short-wave infrared common mirror group L9, a second spectroscope L10, a laser emission mirror group L11, an optical fiber light source S1 and a short-wave infrared mirror group L12. The system comprises an imaging light path and a laser emission light path.

The invention relates to a terahertz radar imaging system based on four-inch spinning, which belongs to the technical field of terahertz wave imaging and comprises a femtosecond laser light source, a beam splitter, a laser pumping terahertz transmitting module, a detection laser transmission module and a terahertz detection module which are arranged along the laser incidence direction. An efficient, large-size and ultra-wideband terahertz radiation source and a radar imaging device are fused, high-signal-to-noise-ratio and high-resolution terahertz imaging of a large-size target is achieved, and the system is low in cost, easy to construct, free of complex parabolic mirror combination, firm and reliable in performance and suitable for large-size target imaging. And the requirements of various engineering application scenes on synthetic aperture and nondestructive detection imaging can be practically met.

The invention relates to an optical fiber communication sensing integrated architecture and a working method thereof. Comprising a sensing system laser, a coupler, a polarization beam splitter, a semiconductor optical amplifier, a polarization multiplexing communication transmitting system, a polarization wavelength two-dimensional demultiplexer, namely a WDM-PM device, a coarse wavelength division multiplexer MMI-WDM, a single-mode fiber, a polarization multiplexing communication receiving system, a polarization diversity double-balanced photoelectric detector PBPD, and an ROTDR and phi OTDR data processing unit. According to the invention, not only can high-capacity and long-distance communication under fusion of polarization multiplexing and wavelength division multiplexing be realized, but also sensing and communication can be fused through a wavelength division multiplexing system, the quality of sensing signals is improved through polarization diversity reception on the basis, and mutual promotion of communication and sensing is realized.

The invention discloses an underwater active polarization imaging device based on a liquid crystal phase retarder, which comprises a CCD (Charge Coupled Device) camera, an optical filter, a beam splitter prism, the liquid crystal phase retarder, a polarizer, a front lens and an annular active light source which are sequentially arranged on the same straight line, and the imaging device is arranged in front of a shot target at an object distance capable of clearly imaging; wherein the rotating table, the liquid crystal controllable phase delayer, the annular active light source and the CCD industrial camera are connected to a computer for control and image processing, and the underwater active polarization imaging device calculates a Stokes vector of a shot target by shooting a plurality of polarization images with different polarization angles and polarization states; according to the method, the image of the target object is acquired through the polarization information of the object, the influence of scattering absorption of underwater impurities can be eliminated, and an underwater high-definition image is presented through relative algorithm optimization.

The invention discloses a liquid guide laser processing device and method based on double-beam phase adjustment, belongs to the technical field of laser processing, and aims to reduce the width of a laser beam. The device comprises a laser light source, a first polarization state modulator, a beam splitter, a spatial light modulator, a second polarization state modulator, a polarization beam combiner and a coupler. A laser light source emits linearly polarized light, the linearly polarized light is converted into circularly polarized light through a first polarization state modulator, then the circularly polarized light is separated into first linearly polarized light and second linearly polarized light through a light beam separator, and on a second linearly polarized light transmission light path, a spatial light modulator adjusts the marginal region phase of the circularly polarized light to enable the marginal region phase to differ from the marginal region phase of the first linearly polarized light by a half cycle. And the second polarization state modulator adjusts the polarization direction to be the same as that of the first linearly polarized light, the polarization beam combiner combines the two beams of light, the coupler couples the combined laser beams to the liquid jet flow, and the liquid jet flow acts on the workpiece to be machined, so that optimization of the diameter of the laser beams is achieved.

The invention provides a laser beam splitting multi-galvanometer parallel scanning processing system, which comprises a laser, a beam splitter group, a plurality of groups of collimation beam expanders, a plurality of groups of attenuators and a plurality of focusing scanning galvanometer systems, and is characterized in that the beam splitter group comprises at least one total reflection mirror and at least one beam splitter, and the axial leads of all lenses in the beam splitter group are parallel to one another; the beam splitter group is used for equally dividing a laser beam output by the laser into a plurality of parallel light beams with the same power, a light path where each parallel light beam is located is sequentially connected with a group of collimation beam expanders, a group of attenuators and a focusing scanning galvanometer system, and each focusing scanning galvanometer system is used for focusing each parallel light beam to a to-be-processed plane. According to the invention, the effect of multi-beam and multi-galvanometer parallel scanning processing is realized through beam splitting of a single laser, the scanning breadth is effectively expanded, the manufacturing efficiency is improved, the input power of each light path is independently controllable, and the equipment cost is greatly reduced.

The invention discloses a calibration device based on a polarization focusing optical system. The calibration device comprises a beam splitter prism assembly. The photoelectric autocollimator and the high-precision adjusting rotary table are arranged on one side of the light inlet end of the beam splitter prism assembly; detected moving parts are arranged at the light emitting ends of the two sides of the beam splitter prism assembly; one end, matched with the light emitting end of the beam splitter prism assembly, of the detected moving part is provided with a coaxial lens barrel assembly; according to the calibration device, the straightness, the parallelism and the coaxiality of measured moving parts on the two sides are measured through a beam splitter prism assembly and a photoelectric autocollimator; when the straightness and the parallelism of the measured moving part are measured, the light emitting end of the beam splitter prism assembly is not provided with the switching objective lens; when the coaxiality of the measured moving part is measured, the switching objective lens is installed at the light emitting end of the beam splitter prism assembly. According to the calibration device, the shafting can be synchronously adjusted on line.

The invention discloses a low-power-consumption multiple-input-multiple-output thermo-optical switch chip which comprises N optical input ports, an N * N optical beam splitter, N spiral waveguide thermo-optical phase shifters, an N * N optical beam combiner and N optical output ports. The N * N light beam splitter and the N * N light beam combiner adopt the same design structure and comprise N single-mode input / output waveguides, N width gradient waveguide transition areas (taper areas) and a multi-mode waveguide area, and each single-mode input and output waveguide is connected to the multi-mode waveguide area through the width gradient waveguide transition area. The spiral waveguide thermo-optic phase shifter comprises two spiral waveguides with different sizes, an S bend with a gradually-changed width and a circular heating electrode. The transmission path of light in the chip can be changed by adjusting the spiral waveguide thermo-optical phase shifter, and the function of optical switch switching is achieved. The invention has the advantages of high integration level, high expandability and low power consumption, and can be used in the field of integrated photon chips.

The invention relates to a visible light / short-wave infrared dual-band common-caliber optical system, which comprises a common-caliber part, a plane beam splitter, a visible light channel subsystem and a short-wave infrared channel subsystem, and is characterized in that the common-caliber part is positioned at the foremost end of the optical system and consists of a primary reflector and a secondary reflector which are coaxially arranged; the plane beam splitter is located on a light path behind the secondary reflector, full-wave-band light from an object side is reflected by the primary reflector and the secondary reflector in sequence, then reaches the plane beam splitter to be split, and then enters the visible light channel subsystem and the short-wave infrared channel subsystem to be imaged in different wave bands, and the optical system achieves dual-wave-band common caliber. According to the invention, the design of long focal length and large aperture of the dual-band system is realized, the target detection / identification capability of the system is improved, the system has the advantages of high spatial resolution, long operating distance and high identification probability, meanwhile, the system structure is effectively simplified, the system volume is reduced, the installation and adjustment difficulty is reduced, and a relatively low obscuration ratio and relatively high imaging quality are realized.

The invention discloses a traceable cavity ring-down spectrometer system with a self-calibration function, and is applied to the technical field of gas concentration detection. The device comprises an optical cavity ring-down main body, a dynamic generation module and a reference analysis module which are connected in sequence, wherein the optical cavity ring-down main body comprises a laser light source, a beam splitter, an optical fiber isolator, a lens, a first reflecting lens, a first aluminum ring, a sample cell, a second aluminum ring, a cross shaft type universal coupling control device and a second reflecting lens which are arranged along a laser light path; the dynamic generation module comprises a high-purity gas inlet, a gas purifier, a dynamic generation device, a standard gas outlet and a three-way electromagnetic valve which are arranged along a gas path; the reference analysis module comprises an instrument standard gas inlet, a reference analyzer and a standard gas storage box which are arranged along the gas path. According to the method, the influence of instrument drift on analysis data caused by the use environment and instrument part loss of the online instrument is avoided, and the accuracy and the quantity value traceability of the instrument analysis data are guaranteed.

Disclosed in the present invention are a photoelectric terahertz hyperspectral imaging system and method based on a swept-frequency dual-comb. The system comprises: a swept-frequency laser, a distributed feedback laser, a dual-comb generation module, a coupling beam splitter, a spectrum analyzer, a variable optical attenuator, a terahertz mixer, an off-axis parabolic mirror group, a zero bias detector, an electric amplifier and a signal analyzer, wherein the tunable distributed feedback laser is mixed with electro-optical dual-comb light to generate a swept-frequency terahertz dual-comb signal, point-by-point imaging of an object is realized by means of grid scanning, the swept-frequency dual-comb breaks the trade-off between a spectral bandwidth and a frequency resolution in a dual-comb system, and a frequency resolution of 50 MHz is achieved under a spectral bandwidth ranging from 220 GHz to 320 GHz. Scanning dual-comb terahertz imaging has a higher data collection rate, a more flexible spectral tuning range and a higher frequency resolution at room temperature, and the system is flexible and configurable, and has a simple structure and a high detection efficiency.

The invention provides an optical measurement method and device, and belongs to the technical field of optical measurement, and the method comprises the steps: starting a light source with the wavelength changing dynamically to generate a sweep frequency optical signal; dividing the light into a measuring beam and a reference beam by using a light splitting component, guiding the measuring beam to irradiate a target to be measured and then return along the same path, and guiding the reference beam to enter an optical component of which the optical path changes along with the wavelength and then return; based on the low-coherence characteristic of the light source, when the optical paths of the two light beams meet the interference condition, detecting an interference signal by using a sensing component; the optical path difference is determined according to time information in the interference signal, and the thickness of each reflection interface is calculated by combining refractive index data of a target to be measured. Different from the traditional low-coherence interference measurement which depends on a motor and the like to control the movement of a reflector, the method avoids the limitation of mechanical driving on the measurement frequency, and achieves the high-speed optical thickness measurement.

The invention discloses a dual-band processing head of micro-jet laser equipment and a focusing regulation and control method of the dual-band processing head, and belongs to the field of micro-jet laser equipment. The dual-band processing head comprises a first laser emitter, a second laser emitter, a main dichroic beam splitter, a dual-band reflector group, a spray head and an imaging module; the first laser transmitter is used for transmitting a first light beam, the second laser transmitter is used for transmitting a second light beam, and the main dichroic beam splitter is used for reflecting the first light beam and transmitting the second light beam; the first light beam is reflected to the dual-band reflecting mirror group through the main dichroic beam splitter and is reflected to the spray head through the dual-band reflecting mirror group, and the second light beam is transmitted to the dual-band reflecting mirror group through the main dichroic beam splitter and is reflected to the spray head through the dual-band reflecting mirror group; a spray hole is formed in the upper surface of the spray head, the first light beam and the second light beam are reflected to the dual-waveband reflector set through the upper surface of the spray head and transmitted to the imaging module through the dual-waveband reflector set, and therefore the machining efficiency of the machining head can be improved.

The invention relates to a double-pump light semi-transparent and semi-reflective miniaturized triaxial SERF atom magnetometer device, which is characterized in that single pump light is guided into a probe by a polarization maintaining optical fiber; and then one beam of pump light is divided into two beams of circular polarization pump light with the same light intensity by using a half-wave plate, a polarization splitting prism, a right-angle reflector and a quarter-wave plate, and then the two beams of circular polarization pump light vertically pass through the same alkali metal gas chamber. After the pump light penetrating through the air chamber passes through the semi-transparent and semi-reflective flat beam splitter, one half of the pump light is detected by the photoelectric detector and used for extracting magnetic field information, and the other half of the pump light returns to the original path and passes through the alkali metal air chamber for the second time. According to the invention, high-sensitivity simultaneous measurement of a three-axis magnetic field of the miniaturized three-axis SERF atom magnetometer is realized, the atomic spin polarizability is enhanced, the uniformity of the atomic spin polarizability in the air chamber is improved, and the technical problem of spin polarizability uniformity in miniaturized application of the SERF atom magnetometer is solved; and the application of the array type triaxial SERF atom magnetometer in the fields of magnetocardiography, brain magnetism and the like is facilitated.

The invention discloses a visible light and short wave infrared common-aperture optical system which is used for solving the technical problem that an existing multi-band common-aperture optical system cannot meet the detection requirements of large view field, high resolution and high sensitivity at the same time. The optical system comprises a visible light optical system and a short-wave infrared optical system, and a primary reflector, a secondary reflector, a beam splitter prism, a visible light relay lens group and a first imaging unit jointly form the visible light optical system; and the primary reflector, the secondary reflector, the beam splitter prism, the short-wave infrared image space telecentric relay lens group, the view field divider and the N second imaging units jointly form a short-wave infrared optical system. The optical system disclosed by the invention shares the primary reflector and the secondary reflector, so that the focal length of the optical system is increased, and the requirement of high resolution is met; and meanwhile, the short-wave infrared optical system adopts the view field divider and N second imaging units, and the large-view-field and high-sensitivity infrared detection requirements of the optical system on a dark and weak target are met through splicing of N paths of view fields.

The invention discloses a double-comb non-cooperative target ranging system based on single photon detection, which is characterized in that an optical pulse output by a first optical frequency comb is divided into two paths of light through a first beam splitter, the first path of light is combined with one of two paths of light divided by a second optical frequency comb through a second beam splitter, and the combined light is transmitted to a first nonlinear frequency up-conversion module; a sum frequency light pulse in the wave band of 780 nm is generated and detected by a base avalanche diode photoelectric detector, and then a time-dependent single photon counter is triggered to start counting; the second path of light is output to a beam expanding collimator through the circulator and irradiates a target to be measured through spatial propagation, the beam expanding collimator collects diffuse reflection light and returns the diffuse reflection light to a third port of the circulator along the original path, and the diffuse reflection light and the other path of light split by the second optical frequency comb through the second beam splitter are combined and transmitted to a second nonlinear frequency up-conversion module; the up-conversion light after sum frequency conversion passes through the optical filter group and then is recorded by a stop end of the single photon counting module, multi-cycle accumulative statistics is carried out by the time correlation single photon counter, and finally a photon counting waveform is reconstructed and the flight time difference of the to-be-measured target is calculated by the computer.

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.