1428 results about "Waveplate" patented technology

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 provides a visual system, which comprises an element group and a lens cone group, when the diopter of the visual system is from + 2D to-5D, the moving distance delta L of the second element group along the optical axis, the combined focal length fz1 of the reflective polarizing element, the first quarter-wave plate and the first lens, and the combined focal length fz2 of the second lens, the second quarter-wave plate and the polarizing film meet the condition that delta L * (fz1 / fz2) is greater than or equal to 0.90 mm and less than or equal to 1.82 mm; and the maximum thickness Lb from the first side surface of the second lens barrel to the second side surface of the second lens barrel along the direction of the optical axis, the outer diameter Dbs of the first side surface of the second lens barrel and the inner diameter dbs of the first side surface of the second lens barrel meet the condition that Lb / (Dbs-dbs) is more than or equal to 0.56 and less than or equal to 2.36. The problem that smooth zooming and image quality improvement of a visual system in the prior art are difficult to consider at the same time is solved.

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.

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 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 provides a low-chromatic-aberration transparent display device in order to solve the problem that chromatic aberration easily occurs in polarization modulation stereoscopic display adopting a 1 / 4 wave plate. The low-color-difference transparent display device comprises a directional polarization light source, a reflector and a transparent liquid crystal display panel. The pixels on the upper portion of the 2D display panel are lightened in a time-division multiplexing mode and any time slice slot, light rays of the pixels are projected through the lens array and then reflected through the reflector, the polarization direction of the light rays is adjusted, and then the light rays penetrate through the transparent liquid crystal display panel to form viewpoints. The transparent liquid crystal display panel synchronously provides a parallax image corresponding to the viewpoint position. The sub-pixel value of any one lightened pixel on the 2D display panel is modulated to be a fixed value related to the included angle of the lens, so that colored light generated by the pixel is restored to be white light after being polarized by the polarizer, the polarization direction is adjusted by the 1 / 4 wave plate and the polarization of the analyzer. At the moment, a directional light source without chromatic aberration is provided for the transparent liquid crystal display panel, so that chromatic aberration introduced by the polaroid and the wave plate is reduced.

The invention provides a VR visual system, the VR visual system comprises an element group and a lens cone group, the element group sequentially comprises a first element group and a second element group from a first side to a second side along an optical axis of the VR visual system, the second element group can move along the direction of the optical axis, the combined focal length fz1 of the reflective polarizing element, the first quarter-wave plate and the first lens and the inner diameter dam of the second side surface of the first lens barrel meet the condition that fz1 / dam is more than or equal to 1.60 and less than or equal to 2.66; and the outer diameter Dbs of the first side surface of the second lens cone, the inner diameter dbs of the first side surface of the second lens cone and the distance delta L of the second element group moving along the optical axis when the diopter of the VR visual system is from + 2D to-5D meet the following condition: (Dbs-dbs) / delta L is greater than or equal to 2.63 and less than or equal to 7.45. The VR visual system solves the problem that a VR visual system in the prior art is large in diopter adjustment range and is difficult to consider the structural stability at the same time.

The invention relates to an optical fiber coupling dynamic interferometer based on arrayed waveguide grating light splitting. A luminous source and an arrayed waveguide grating of the optical fiber coupling dynamic interferometer are arranged on a motion module. The light emitting source is connected to the input port of the array waveguide grating through an optical fiber, and through the movement module, any one of the multiple output ports of the array waveguide grating is in butt joint with the optical fiber connected to the incident end of the collimation structure. A half-wave plate and a beam splitter prism of the imaging element group are sequentially arranged on an emergent light path of the emergent end of the collimation structure, and the beam splitter prism is used for splitting a light beam passing through the half-wave plate into a reference light beam transmitted along a first light path and a measurement light beam transmitted along a second light path. And the reflecting mirror of the imaging element group reflects the reference light beam back to the beam splitting prism. And the to-be-measured surface reflects the measurement light beam back to the beam splitter prism. The reference beam and the measurement beam reflected back to the beam splitter prism interfere with each other and are imaged on the target surface of the camera. Accurate measurement of the wavefront image of the surface to be measured is realized.

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 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.

According to the measuring equipment provided by the invention, based on the light path design of double Fizeau interferometers, the third quarter-wave plate is arranged between the first PBS beam splitter prism and the first protective glass, and the fourth quarter-wave plate is arranged between the second PBS beam splitter prism and the second protective glass; the first protection glass reflects part of incident light beams to the third quarter-wave plate and then reflects out of a light path after passing through the first PBS prism, and the second protection glass reflects part of incident light beams to the fourth quarter-wave plate and then reflects out of the light path after passing through the second PBS prism. Therefore, light reflected by the paired protective glass is prevented from entering the interferometer on the side, crosstalk is filtered out, and the measurement precision is ensured.

The embodiment of the invention relates to the technical field of display, and provides a lens assembly, an optical system and display equipment. The lens assembly comprises a plurality of lenses which are sequentially arranged from an object side to an image side; the light splitting element, the first quarter-wave plate and the reflection polarization element are sequentially arranged from the object side to the image side; and a lens barrel. At least one of the first quarter-wave plate and the reflective polarization element is fixed on the lens barrel independent of the plurality of lenses; or the object side surfaces and the image side surfaces of the plurality of lenses comprise at least one binding surface, and at least one of the first quarter-wave plate and the reflection polarization element is bound on the binding surface. And the binding surface is a quadric surface of which the curvature in at least one direction is zero.

The utility model discloses a visual system which comprises a lens cone, a lens group and a spacing element group, wherein the lens group and the spacing element group are assembled in the lens cone; the lens group comprises a first lens with positive focal power, a reflective polarization element, a first quarter-wave plate, a second lens with positive focal power, a third lens with negative focal power, a partial reflection element and a second quarter-wave plate which are sequentially arranged from the first side to the second side along the optical axis. The fourth lens has negative focal power; the spacing element group comprises a first spacing element, a second spacing element, a third spacing element and a fourth spacing element; wherein the number of the lenses with focal power in the lens group is four; the effective focal length f1 of the first lens and the effective focal length f of the visual system satisfy 1.5 lt; f1 / flt; 1.9); the combined focal length FG1 of the first lens, the reflective polarizing element and the first quarter-wave plate and the inner diameter d1s of the first side surface of the first spacing element meet the following conditions: 2.35 lt; fG1 / d1slt, FG1 / d1slt; and 2.75%.

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 provides a visual system. The visual system comprises a lens cone, a lens group and a spacing element group, the lens group and the spacing element group are arranged in the lens cone, and the lens group is composed of four lenses, a polaroid, a reflective polarizing element, a quarter-wave plate and a reflective element. The four lenses are sequentially a first lens with positive focal power, a second lens with negative focal power, a third lens with negative focal power and a fourth lens with positive focal power from the first side to the second side; f23 / d3s is more than or equal to-9.75 and less than or equal to-8.72; f / (CP1 + EP13) is more than 5.00 and less than 5.40. The problem that stray light is serious due to the fact that a four-piece type visual system in the prior art is provided with a bonding lens and a reflecting part to meet the requirement for structure compactness is solved.

The utility model discloses an optical imaging system. The optical imaging system comprises a lens cone, an imaging group and a second spacing element, wherein the imaging group and the second spacing element are arranged in the lens cone. The imaging group sequentially comprises a linear polarization film, a reflective polarization element, a quarter-wave plate, a first lens, a second lens, a third lens, a fourth lens and a partial reflection layer from the first side to the second side along the optical axis; wherein the first lens and the second lens are glued, and the third lens and the fourth lens are glued. The second spacer element is disposed on the second side of the second lens and is in contact with the second side of the second lens. Wherein the outer diameter D0m of the second side end face of the lens barrel and the outer diameter D2m of the second side face of the second spacing element meet the condition that D0m-D2m is larger than or equal to 4.51 mm and smaller than or equal to 5.8 mm; the inner diameter d2m of the second side surface of the second spacing element, the inner diameter d2s of the first side surface of the second spacing element, and the axial distance T23 from the second side surface of the second lens to the first side surface of the third lens satisfy the following formula: (d2m-d2s) / T23 is greater than or equal to 0.97 and less than or equal to 2.79.

The invention relates to the technical field of optical measurement, in particular to a grating interference measuring device and method based on large-size light spots. The device comprises a light source module which adopts a laser light source with high stability, and the laser light source comprises a wavelength locking device; the collimation and beam expansion module is connected with the light source module; the light splitting module adopts a combined structure of a polarization splitting prism and a lambda / 4 wave plate; the reference grating module comprises a reference grating and a three-dimensional precision adjustment platform; the measuring grating module comprises a measuring grating and a self-adaptive height adjusting mechanism; the imaging module comprises a large-view-field telecentric imaging lens group and a high-speed CMOS image sensor; and a data processing module. One-time measurement of the surface of a large-area object is achieved through the collimation and beam expanding module, efficiency is improved, local interference errors are reduced, the stable laser light source and the reasonable design module are adopted, environmental influences are reduced, optical design is optimized, aberration is reduced, automatic and intelligent measurement is achieved, and convenience and efficiency are improved.

The invention relates to the field of optical detection, in particular to an interference confocal measurement system based on space coding and a measurement method thereof.White light generated by a light source is collimated through a first collimating lens and then divided into S polarized light and P polarized light through a polarization splitting prism, the S polarized light enters a reference plane mirror through a first quarter-wave plate, and the P polarized light enters a second quarter-wave plate; p polarized light enters a blazed grating through a second quarter-wave plate for transverse dispersion and then is changed into monochromatic polarized light with different wavelengths and the same focal length through a first achromatic lens, and the monochromatic polarized light and the monochromatic polarized light are jointly focused at the same depth position of an object to be measured. Information of the object to be measured is carried and returned to the polarization splitting prism, two beams of polarized light are combined and then focused on a target surface of a photoelectric detector of an imaging spectrometer with a mask plate through a focusing lens, an interference image of the object to be measured is obtained, and spectrum and interference analysis is carried out. According to the invention, the transverse scanning speed can be improved, the measurement time can be shortened, and the resolution can be improved.

The invention provides a device for generating multiple beams of time sequence light based on a single-circle light spring, and relates to the technical field of ultrafast imaging, and the device comprises a leading edge tilt pulse generation system which is used for generating a long elliptical leading edge tilt pulse; the light spring generation system comprises a polarizer, a first wave plate, a diaphragm, a geometric conversion device, a convex lens, a phase compensator and a second wave plate which are sequentially arranged along the pulse propagation direction, and generates a single circle of light spring pulse based on the long elliptical leading edge tilt pulse output by the leading edge tilt pulse generation system; and the time sequence light beam generation system is used for dividing the single-circle light spring pulse into a plurality of beams of time sequence light through a circular porous diaphragm and a lens group. According to the invention, multiple beams of time sequence pulses can be generated as a coherent shutter to interfere with a signal light beam carrying ultrafast event information, multiple beams of time sequence light can be efficiently generated, multi-beam interference noise is optimized, and efficient image separation of ultrafast imaging is realized.

The invention discloses a high-speed high-resolution compressed sensing imaging system and an imaging method. Light of an object is emitted to the polarization splitting prism to be transmitted and reflected after passing through the first-stage imaging module, the transmitted light is reflected back to the polarization splitting prism after being coded and modulated by the spatial light modulator, and then the transmitted light enters the target surface of the camera through the second-stage imaging module to form a coded imaging image; the reflected light is transmitted to the hollow ridge reflecting prism through the quarter-wave plate, is reflected back to the quarter-wave plate through the hollow ridge reflecting prism, then sequentially passes through the quarter-wave plate, the polarization splitting prism and the secondary imaging module and then enters the target surface of the camera to form a common imaging image, and then coded imaging data is matched with common imaging data; and decoding reconstruction is carried out by adopting an alternating direction multiplier method of a point spread function integrated with the first-stage imaging module and the second-stage imaging module. Compared with a traditional imaging mode, the method can break through the imaging frame rate limit of a camera, and has the advantages of high imaging resolution and small data volume.

The invention belongs to the technical field of optoelectronic devices, and provides a laser gyroscope frequency stabilization system and a frequency stabilization method thereof.The laser gyroscope frequency stabilization system comprises a large laser gyroscope to be subjected to frequency stabilization, an electro-optical modulator, an adjusting light path, a signal generator, a mode matching mirror set, a PID regulator, a frequency mixer, a photoelectric detector, an ultra-stable cavity, a low-pass filter, a computer and a data acquisition card; and a square transmission light path is arranged in the ultra-stable cavity. According to the invention, the problem of insufficient isolation caused by an optical isolator consisting of a polarization splitting prism and a 1 / 4 wave plate is effectively avoided, the influence of an optical feedback effect is reduced, and the optical isolator is better adapted to the field of high-precision measurement related to a large laser gyroscope.

The invention discloses a large-aperture plate glass stress birefringence surface imaging measurement method, belongs to the technical field of optical measurement, and aims to solve the technical problem of low glass stress birefringence measurement efficiency in the prior art. Comprising the following steps: moving a sample to be measured and a 1 / 4 wave plate out of a measuring light path, rotating a polarizer to find an extinction position, and rotating the polarizer by N angles nearby to obtain an angle # imgabs0 #; keeping the polarizer and the analyzer unchanged, moving the 1 / 4 wave plate into a measurement light path, rotating the 1 / 4 wave plate, and finding an extinction position; rotating the polarizer by N angles near the extinction position to obtain an angle # imgabs 1 #; the positions and the directions of the 1 / 4 wave plate and the polarization analyzer are kept unchanged, and the sample to be measured is moved into a measuring light path between the polarizer and the 1 / 4 wave plate; the polarizer is rotated through the polarization rotating mechanism, when the included angles between the polarizer and the x axis of the reference coordinate system are 0 degree, 60 degrees and 120 degrees respectively, the light intensities of the three images are obtained through the CCD camera, and the stress birefringence of the sample to be measured is obtained according to the three light intensities.

A visual optical system comprises a first optical system and a second optical system. The first optical system comprises a first lens having a positive refractive power, a reflective polarizing element, a quarter-wave plate, a second lens having a refractive power and a third lens having a positive refractive power. The second optical system comprises, sequentially along a second optical axis from the first side to the second side, first to sixth lens elements. An effective focal length f3′ of the third lens, a distance TD′ from a first-side surface of the first lens to a second-side surface of the third lens on the first optical axis, an effective focal length f1 of the first lens element and a distance TD from a first-side surface of the first lens element to a second-side surface of the sixth lens element on the second optical axis satisfy: 1.9<(f3′ / TD′) / (|f1| / TD)<5.7.

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 utility model discloses an optical system. The optical system sequentially comprises a first lens, a reflective polarizing element, a first quarter-wave plate, a second lens, a third lens, a partial reflection element, a second quarter-wave plate, a polarizing film and a fourth lens from a first side to a second side along an optical axis, the first lens has positive focal power, and the first side surface of the first lens is a convex surface; the second lens has negative focal power, the first side surface of the second lens is a plane, and the second side surface is a concave surface; the second side surface of the third lens is a convex surface; the first side surface of the fourth lens is a plane; the effective focal length f1 of the first lens and the effective focal length f2 of the second lens meet the following formula:-0.7 lt; f1 / f2lt; -0.15, < = 0.15; the combined focal length fz2 of the second quarter-wave plate, the polaroid and the fourth lens and the curvature radius R8 of the second side face of the fourth lens meet the condition that fz2 / R8 is larger than or equal to-2.0 and smaller than or equal to-1.5.

The invention belongs to the technical field of optical imaging, and discloses a multifunctional image edge enhancement device based on spiral phase contrast imaging, which comprises a light source system, an optical imaging system and an edge enhancement detection system which are arranged in sequence, the light source system is used for generating collimated linear polarization laser; the optical imaging system comprises a first 4-f system and a round hole diaphragm which are sequentially arranged on a light path; a sample to be tested is arranged between the light source system and the first 4-f system; the edge enhancement detection system comprises a first lens, a vortex wave plate, a second lens and an imaging unit which are sequentially arranged on a light path; the first lens and the second lens form a second 4-f system; linearly polarized laser output by the light source system is transmitted by a to-be-detected sample, enters the first lens after passing through the first 4-f system and the round hole diaphragm, and then is imaged on the imaging unit after passing through the vortex wave plate and the second lens in sequence. According to the invention, edge enhancement can be realized, and the contrast and resolution of the image are improved.

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.

The invention discloses a method and device for measuring a crystal electro-optical coefficient at low voltage, and relates to the technical field of photoelectric coefficient measurement, and the method comprises the steps: employing a wavelength tunable laser as an incident light source of a crystal electro-optical coefficient detection system; before an incident light source is input into a to-be-measured laser crystal, a wave plate is added to serve as a phase compensator to generate phase delay phi 1, and meanwhile the to-be-measured laser crystal generates phase delay phi 2 under the action of direct-current voltage; when the crystal electro-optical coefficient detection system is a half-wave voltage detection system; adjusting the wavelength of the tunable laser so that 3pi / 4 is less than or equal to phi1lt; pi; when the crystal electro-optical coefficient detection system is a full-wave voltage detection system, the wavelength of the tunable laser is adjusted to enable 7pi / 4 to be smaller than or equal to phi1lt; 2pi. As the used light source is the wavelength tunable laser, phi 1 can be adjusted in a large range by changing the wavelength, so that phi 2 and the test voltage are changed, the purpose of measuring the electro-optical coefficient of the crystal at low voltage is achieved, and the test safety is improved.

The invention relates to the technical field of laser, and provides a high-power pulse width repetition frequency tunable laser, which comprises an input and output light path configured to input seed light and output amplified laser; a regenerative amplifier optical path configured to amplify the input seed light; and the pulse width compression module is configured to perform pulse width compression on the amplified seed light and output high-power pulse laser with tunable pulse width, and the pulse width compression module comprises a third polarizing beam splitter, a third 1 / 2 wave plate, a first electric control transverse movement plane mirror, a second electric control transverse movement plane mirror, a nonlinear crystal and a fourth plane mirror. On the basis of a nonlinear crystal multi-pass compression method, a high-power disc laser is built, pulse width compression is carried out on an annular cavity which contains a nonlinear crystal and a 1 / 2 wave plate or is added into a Pockels cell, and a high-power pulse width repetition frequency tunable pulse string is finally obtained by transversely moving a plane mirror through electric control.