52 results about "Wollaston prism" patented technology

The invention discloses a transient absorption spectrum measurement system, method and device for polarized light, and relates to the technical field of ultrafast spectrum measurement. In the system, a laser generation device generates first laser and second laser, and the first laser is converted into left-handed circularly polarized light or right-handed circularly polarized light through a pump light polarization device to serve as pump light for exciting a sample to be detected; the first Glan prism converts the second laser into detection light which is linearly polarized in a specified direction so as to detect the sample to be detected; the first lambda / 4 wave plate is used for converting the detection light after detecting the to-be-detected sample into linearly polarized light with mutually vertical polarization; the Wollaston prism enables the linearly polarized light with mutually vertical polarization to be respectively transmitted to the measuring device along different directions; the measuring device calculates the transient absorption spectrum of the left-hand circularly polarized probe light and the transient absorption spectrum of the right-hand circularly polarized probe light. The system can simultaneously measure the transient absorption spectrums of the left-hand circularly polarized light and the right-hand circularly polarized light, so that the measurement error is reduced.

The invention discloses a polarization imaging device and a polarization analysis method based on single-frame polarization collinear holography, and relates to the field of polarization imaging.According to the polarization imaging device, through combination of optical elements such as a half-wave plate, a Wollaston prism and a CCD camera, spatial multiplexing of a detector plane is carried out, and the polarization collinear holography is obtained. And four polarization collinear holograms can be simultaneously acquired by a single frame. According to the polarization analysis method, a Fourier transform auxiliary angular spectrum method is adopted to analyze an intensity distribution diagram of a polarization collinear hologram to estimate initial wavefront distribution, and an iterative finite support constraint selection method is adopted to solve the problem of twin images in the polarization collinear hologram. And further quantizing a complete Jones matrix and a complete Stokes parameter from the finally reconstructed complex amplitude information. The invention solves the problems of high complexity and long processing time caused by independent reconstruction of amplitude, phase and polarization in the traditional polarization holographic technology, and effectively solves the problem that the traditional off-axis polarization holographic imaging system limits the size of an imaging field of view.

The invention relates to a high-power optical fiber device refractive index dual-wavelength polarization holographic microscopic three-dimensional detection system based on a metasurface cylindrical lens and a working method, and belongs to the field of optical measurement. Comprising a first laser, a second laser, a first reflecting mirror, a first non-polarized beam splitting prism, a first half-wave plate, a beam expander, a polarized beam splitting prism, a second reflecting mirror, a first metasurface cylindrical lens pair, a Wollaston prism, a second half-wave plate, a third reflecting mirror, a second metasurface cylindrical lens pair, a sample optical fiber, a second non-polarized beam splitting prism and a first optical filter. The device comprises a first optical filter, a first CCD detector, a second optical filter, a second CCD detector and a computer. A metasurface cylindrical lens, a dual-wavelength polarization phase fusion interference detection method and a full-aperture aberration elimination filtering back projection refractive index three-dimensional reconstruction method are adopted, and the three-dimensional distribution detection precision and efficiency of the refractive index and welding defects of the high-power optical fiber device are further improved.

The invention relates to the technical field of laser quantum interference measurement, in particular to a three-degree-of-freedom angle measurement device and method based on radial polarized light, which can realize high-precision simultaneous measurement of three-degree-of-freedom tiny angles by utilizing the characteristics of the radial polarized light and combining an advanced optical system and a signal processing technology. By adopting an auto-collimation technology principle, the tight focusing characteristic of radial polarized light and the light splitting characteristic of a Wollaston prism are combined, so that technical indexes such as angle measurement resolution and angle measurement precision can be effectively improved; the roll angle measuring system formed by using the focusing characteristic of the all-dielectric super-lens array and the CCD camera can greatly improve the roll angle measuring precision of the existing method.

The invention discloses a three-port reflection-type circulator and a preparation method thereof, the three-port reflection-type circulator comprises a three-fiber tail fiber, an annular core and a plurality of glass tubes, the tail fiber end face of the three-fiber tail fiber is subjected to thermal core expansion treatment, the annular core comprises a polarization beam splitting assembly, an optical rotation assembly and a refraction assembly, the polarization beam splitting assembly comprises a displacement crystal, and the displacement crystal is connected with the optical rotation assembly. The optical rotation assembly comprises a half-wave plate group, an optical rotation unit, a half-wave plate and a compensation plate, the refraction assembly comprises a collimating lens, a Wollaston prism and a reflective mirror, and the three-fiber tail fiber and the annular core are sleeved through a plurality of glass tubes; wherein light emitted by the three-fiber tail fiber sequentially passes through the polarization beam splitting assembly, the optical rotation assembly and the refraction assembly, is reflected by the reflective mirror, sequentially passes through the refraction assembly, the optical rotation assembly and the polarization beam splitting assembly and returns to the three-fiber tail fiber. The three-port reflective circulator in the embodiment of the invention is more compact in structure and smaller in size, and can be widely applied to the technical field of optical devices.

The invention relates to a laser grooving device and method for a wafer. The device comprises a laser; the first beam expander is located on the path of the laser beam; the first light splitting crystal is located on the side, away from the laser, of the first beam expander and used for receiving the light beams collimated and expanded by the first beam expander to form a first light beam and a second light beam, the first light beam enters a first light path assembly to form a first processing light beam, and the second light beam enters a second light path assembly to form a second processing light beam; the second light beam enters a second light path assembly to form a second processing light beam; the second light splitting crystal is located on the path of the first processing light beam and the path of the second processing light beam and used for forming a first emergent light beam of the first processing light beam and a second emergent light beam of the second processing light beam, and the path of the first emergent light beam is the same as that of the second emergent light beam; a Wollaston prism; and a focus lens. By adopting the method, the processing efficiency can be improved.

The invention discloses an active focusing module of pathological section scanning equipment based on weak measurement, which is characterized in that incident light in a preset polarization state is emitted by a light source and is divided into first reference light and detection light through a polarization splitting prism and a Wollaston prism; the first reference light is reflected by the lower surface of the cover glass to form second reference light, the detection light is reflected by the surface of the sample to form sample light, and the second reference light and the sample light enter the Wollaston prism again for weak coupling and beam combination to form emergent light; the emergent light is received by a spectrometer after phase modulation and polarization selection, and the center-of-gravity shift of the double-peak spectrum can reflect the fluctuation height change of the surface of the sample, so that high-precision focusing is realized. According to the technology, the weak measurement principle is utilized, tiny physical quantity changes are converted into observable spectrum shift, the theoretical sensitivity reaches the picometer level, the focusing accuracy is remarkably improved, and the definition of a scanned image is guaranteed.

A laser optical system and an adjustment method therefor, and a laser machining device and method capable of adjusting laser light so as to satisfy criteria of laser machining are provided. The adjustment method of a laser optical system including a plurality of optical element units which are arranged in series on an optical path of laser light and each of which includes a half-wave plate and a Wollaston prism, the laser optical system configured to branch the laser light incident on the Wollaston prism through the half-wave plate into two beams of branched laser light, includes a step of rotating the half-wave plate around the optical path to adjust branching ratios of the branched laser light and a step of rotating the Wollaston prism around the optical path to adjust branching directions of the branched laser light.

The present application relates to the technical field of laser quantum interference measurement, in particular to a three-degree-of-freedom angle measurement device and method based on radial polarized light, which can realize high-precision simultaneous measurement of three-degree-of-freedom small angles by using the characteristics of radial polarized light, combining advanced optical systems and signal processing technology. By using the self-collimation technology principle, the tight focusing characteristics of radial polarized light and the light splitting characteristics of Wollaston prism are combined, which can effectively improve the angle measurement resolution, angle measurement accuracy and other technical indicators; by using the focusing characteristics of the full-medium super-lens array and the CCD camera, the roll angle measurement system formed can greatly improve the measurement accuracy of the existing method.

The application belongs to the technical field of optical precision measurement, automation control and artificial intelligence, and particularly relates to an interference optical path for obtaining multiple information in single exposure and application thereof, the interference optical path comprising: rotating a polarization direction of a light source through a half-wave plate to obtain first linearly polarized light; the first linearly polarized light is evenly divided into reference light and test light by a common beam splitter; the reference light passes through a quarter-wave plate back and forth to obtain second linearly polarized light orthogonal to the first linearly polarized light; the test light is decomposed into third linearly polarized light and fourth linearly polarized light by a Wollaston prism; the third linearly polarized light and the fourth linearly polarized light irradiate on a measured object, pass through the Wollaston prism again after reflection, and are combined with the second linearly polarized light at the common beam splitter; the combined light beam is received by a polarization resolution camera and records interference signals.The application can realize absolute phase reconstruction in single exposure, and is suitable for measuring refractive index distribution of dynamic or environment-sensitive samples.

The utility model relates to the technical field of light beam separation angle measurement, and discloses a testing device for measuring a Wollaston prism light beam separation angle, which comprises a laser beam generator used for emitting a light beam; the first plane mirror is used for carrying out first reflection on the light beam emitted by the laser beam generator; the second plane mirror is used for carrying out second reflection on the light beam reflected by the first plane mirror; the sample objective table is used for placing a Wollaston prism sample and enabling the light beam reflected by the second plane mirror to enter the Wollaston prism sample; the light beam analyzer is used for receiving two light beams emitted by the Wollaston prism sample; the displacement driving motor is used for driving the light beam analyzer to move back and forth; the optical bread board is used for fixing the laser beam generator, the first plane mirror, the sample objective table and the displacement driving motor; the Wollaston prism beam splitting angle measuring device is high in moving precision and repeatability, and ensures that the Wollaston prism beam splitting angle is accurately measured and calculated.

This invention relates to a circular dichroism spectroscopy measurement system based on heterodyne phase modulation. It includes a broadband light source, a polarizer, a chiral sample, an α-BBO crystal, a Wollaston prism, two optical fibers, a CCD spectrometer, a data transmission line, and a data processing computer. The broadband light source, polarizer, chiral sample, α-BBO crystal, and Wollaston prism are arranged in a straight line. The system operates by combining incoherent spectral acquisition with heterodyne coherent spectral acquisition. During incoherent spectral acquisition, the polarizer's polarization direction is parallel to the Wollaston prism's optical axis, and the CCD spectrometer acquires coherent spectral information. During heterodyne coherent spectral acquisition, the polarizer's polarization direction forms a 45° angle with the Wollaston prism's optical axis, and the CCD spectrometer acquires coherent spectral information. Finally, the circular dichroism spectrum of the chiral sample is obtained through mathematical calculation. This system further improves the signal-to-noise ratio and optimizes measurement accuracy in circular dichroism spectroscopy.

The light splitting device comprises a first light splitting piece, a first wave plate, a magneto-optical crystal, a Wollaston prism, a second wave plate, a third wave plate and a second light combining piece which are arranged along a light path, the first wave plate is arranged on one light path after light splitting of the first light splitting part so as to ensure that the polarization state of linearly polarized light input into the magneto-optical crystal is kept consistent; the second wave plate and the third wave plate are respectively arranged in one of emergent light paths of the Wollaston prism; and a coil is arranged outside the magneto-optical crystal. According to the utility model, through currents of different magnitudes, the coil generates magnetic fields of different magnitudes, the magnetic fields of different magnitudes generate different rotation angles, the different rotation angles correspond to different sin2theta and cos2theta, and furthermore, through the Wollaston prism, two polarization states have light splitting of different proportions. And two beams of light with different splitting ratios are formed after beam combination.

The present invention discloses an active focusing module for a pathology slice scanning device based on weak measurement. The module emits incident light of a preset polarization state through a light source, which is divided into a first reference light and a detection light by a polarization beam splitter prism and a Wollaston prism. The first reference light is reflected by the lower surface of the cover glass to form a second reference light, and the detection light is reflected by the sample surface to form a sample light. The two then enter the Wollaston prism again for weak coupling and are combined into an outgoing light beam. The outgoing light is received by a spectrometer after phase modulation and polarization selection. The center of gravity offset of its bimodal spectrum can reflect the height variation of the sample surface, thereby achieving high-precision focusing. This technology utilizes the principle of weak measurement to convert tiny physical quantity changes into observable spectral offsets. The theoretical sensitivity reaches the picometer level, significantly improving the focusing accuracy and ensuring the clarity of the scanned image.

The application discloses a kind of double-beam included angle self-compensation's roll angle measuring device and method, measuring device is composed of transmitting end and receiving end, transmitting end includes laser, first beam splitter, second beam splitter, third beam splitter, first mirror, second mirror, Wollaston prism, first quadrant photodiode, second quadrant photodiode, first photodiode, second photodiode;Accepting end includes polarizing beam splitter, third mirror, first right-angle prism and second right-angle prism;Receiving end is installed on the measured object.The application will be based on two collimated light beams measurement roll angle and based on polarization measurement roll angle two methods are combined, by the roll angle compensation calibration light path based on polarization designed to be applied to the roll angle measurement system based on two collimated light beams, greatly improve the real-time measurement accuracy of roll angle under long distance.

The utility model relates to an intracavity frequency doubling laser, which comprises a pumping source, a light beam combiner and a bidirectional optical amplifier, and is characterized in that a first optical fiber collimator, a first Wollaston prism, a first roof prism, a first Faraday rotator, a polarizer, a frequency doubling crystal, a first reflection cavity mirror and a second reflection cavity mirror are sequentially arranged on one side of the bidirectional optical amplifier along an optical path; and a second optical fiber collimator, a second Wollaston prism, a second roof prism, a second Faraday rotator and a rectangular prism are sequentially arranged on the other side of the bidirectional optical amplifier along the optical path. According to the utility model, the two Faraday rotators and the polarizer are utilized, the oscillation of the linear polarization fundamental frequency laser is realized by using the non-polarization-maintaining gain fiber, the generation of the frequency doubling laser is realized through the frequency doubling crystal in the cavity, and finally the stable frequency doubling laser is output through the endoscope; the utility model has the characteristics of low manufacturing cost, high extinction ratio and high frequency doubling efficiency.

The invention discloses a Wollaston prism-based carrier frequency interference detection device and a Wollaston prism-based carrier frequency interference detection method, which are characterized in that a Wollaston prism is used for separating reference light from test light at a small angle to realize carrier frequency, so that a return error generated by a method for introducing the carrier frequency by inclining a to-be-detected object at a certain angle originally is avoided; and high-precision carrier frequency interference detection is realized. The Wollaston prism is moved through the high-precision displacement table, so that the detection device can be compatible with carrier frequency interference detection and normal Fizeau interference detection. By designing the relay lens with the ultra-low return error, the return error in an interference detection light path is further reduced, and the detection precision is ensured. According to the invention, the dynamic carrier frequency interference detection of the surface shape of the to-be-detected object can be effectively realized with high precision.

The application discloses a three-port reflective circulator and a preparation method thereof. The three-port reflective circulator comprises a three-fiber pigtail, a ring-shaped core and a plurality of glass tubes. The tail fiber end face of the three-fiber pigtail is subjected to a hot expansion core treatment. The ring-shaped core comprises a polarization beam splitting assembly, a rotary optical assembly and a refractive assembly. The polarization beam splitting assembly comprises a displacement crystal. The rotary optical assembly comprises a half-wave plate group, a rotary optical unit, a half-wave plate and a compensating plate. The refractive assembly comprises a collimating lens, a Wollaston prism and a mirror. The three-fiber pigtail and the ring-shaped core are sleeved by the plurality of glass tubes. In the application, the light emitted by the three-fiber pigtail passes through the polarization beam splitting assembly, the rotary optical assembly and the refractive assembly in sequence, is reflected by the mirror, and returns to the three-fiber pigtail by passing through the refractive assembly, the rotary optical assembly and the polarization beam splitting assembly in sequence. The three-port reflective circulator in the application has a more compact structure and a smaller size, and can be widely applied to the technical field of optical devices.

The invention provides an absorption laser differential interferometer. The device comprises a signal generator, a laser controller, a laser, a plane mirror FM, a first variable polarization beam splitter vPBS1, a second variable polarization beam splitter vPBS2, a half-wave plate HWP, a first Wollaston prism Wp, a first optimal shape spherical lens L1p, a second optimal shape spherical lens L2p, a first field lens L1c, a second field lens L2c, a second Wollaston prism WC, a non-polarization beam splitter BS and a quarter-wave plate QWP. A linear polarizer LP; and an oscilloscope. The device is simple and reasonable in structural design, can realize more complete and accurate representation of a high-speed flow field, and realizes multi-parameter synchronous measurement of the flow field; when the two technologies are combined for use, the limitation of a single method can be overcome, the physical integrity of measurement is improved, the applicability in a complex flow environment is enhanced, and the measurement capability in the fields of hypersonic wind tunnel experiments, scramjet engine combustion diagnosis, turbulent flow research and the like is improved.

The invention relates to a phase contrast microscopic imaging device based on miniaturized differential interference. According to the device, light emitted by a white light LED light source is refracted by a hemispherical lens to become parallel light, light path regulation and control are carried out through a polarizer and a beam splitter, and finally the light is guided to a Wollaston prism for differential processing. After being differentiated, the light is focused to the surface of a sample through a gradient refractive index lens. And when the signal light reflected by the sample is differentiated again through the Wollaston prism, the signal light is further processed by the polarization analyzer and the tube lens, and finally a differential signal is focused on the memory, so that imaging is completed. The miniaturized differential interference phase contrast microscopic imaging device has the core advantage that the high-performance gradient refractive index lens is adopted, so that the high-quality imaging effect can be ensured by virtue of the miniaturized design, and meanwhile, the size and the weight of equipment are also remarkably reduced. By integrating a series of miniature optical elements with a storage system, the system greatly reduces the complexity and manufacturing cost of the imaging device. In addition, the device is also combined with a micro-fluidic chip, and a miniaturized blood cell counting device is provided. The compact design of the device enables the device to have wide application potential, the device is particularly suitable for being used in the environment with limited resources, such as rural areas and remote areas, and the problem that local medical resources are deficient can be effectively solved. Through the innovative design, the low-cost and high-efficiency microscopic imaging technology is expected to greatly improve the diagnostic capability of primary medical facilities.

The present invention discloses a transient absorption spectroscopy measurement system, method and device for polarized light, relating to the technical field of ultrafast spectroscopy measurement. In this system, a laser generating device generates a first laser and a second laser. The first laser is converted into left-handed circularly polarized light or right-handed circularly polarized light by a pump light polarization device to serve as the pump light for exciting a sample to be measured. A first Glan prism converts the second laser into linearly polarized probe light in a specified direction to detect the sample to be measured. A first λ / 4 wave plate converts the probe light after detecting the sample to be measured into linearly polarized light with perpendicular polarizations. A Wollaston prism causes the linearly polarized light with perpendicular polarizations to propagate in different directions to a measurement device respectively. The measurement device calculates the transient absorption spectrum of the left-handed circularly polarized probe light and the transient absorption spectrum of the right-handed circularly polarized probe light. This system can simultaneously measure the transient absorption spectra of left-handed circularly polarized light and right-handed circularly polarized light, thereby reducing measurement errors.

The application discloses a kind of dual-channel hyperspectral imaging device and method based on Sagnac interferometer.The incident light from target collimates after passing through pre-imaging objective, diaphragm and collimating objective, and is incident to Wollaston prism again after passing through polarizer, and Wollaston prism shears incident light into different direction o light and e light, and after passing through Sagnac waveband division shear structure, different waveband o light and e light produce different lateral shear amount, and are emitted along different directions, pass through polaroid array and filter array, and finally form spatially separated two different waveband interference images on area array detector by post-imaging objective.The application can obtain two groups of interference images under different wavebands by once push scanning, and realizes high-resolution spectral imaging under wide waveband range.

The invention discloses a method for measuring the particle size of air particles by using a time-of-flight method. A polarized laser beam emitted by a fiber polarized laser passes through a plano-convex cylindrical mirror after being split by a Wollaston prism. The entrance pupil of the plano-convex cylindrical mirror is overlapped with the exit surface of the Wollaston prism to generate two light curtains of the same thickness parallel to the main light. Aspheric reflectors and avalanche diode photodetectors are respectively arranged on both sides of the light curtain. The particles move in a single direction and continuously pass through the two light curtains to generate scattering. The aspheric reflectors collect the scattered light and collect the scattered light to the avalanche diode photodetector. The advantages of the invention are: the invention has a simple structure, uses a small number of optical devices, has a simple later mechanical structure design, is easy to adjust the optical path, and has high measurement accuracy. The most important thing is that there is no optical element behind the condenser, the focusing aberration is small, and a light curtain with a thickness reaching the diffraction limit can be formed.

A multi-focal light-sheet structured illumination system that can be implemented as a part of a commercial fluorescence microscope or a module that is adaptable to fit a number of commercially available microscopes. The system provides simultaneous capture of 2D images from multiple planes within a 3D volume, which are resolved laterally and axially to provide improved resolution along the three dimensions (x,y,z). A Wollaston prism allows several axially-localized high-contrast structured illumination patterns to be generated.

A two-axis homodyne grating interference displacement measurement method and system based on a Wollaston prism and a four-quadrant detector belong to the field of grating interference displacement measurement and are suitable for two-axis homodyne grating interference displacement measurement for synchronous measurement of horizontal and vertical displacements. The method is used for solving the problem that a Wollaston prism (WP) and a four-quadrant detector (QPD) are not matched in the prior art in the two-axis homodyne grating interference displacement measurement occasion. In the method, a certain device in an optical path or a polarization direction of a light beam is rotated, so that a direction of a connecting line of two light beams is perpendicular to a normal direction of a dividing surface of the Wollaston prism. At this time, the two light beams pass through the Wollaston prism to form four light spots in a square distribution, so that the problem of optical path mismatch between the two-axis parallel light and the rotating Wollaston prism is solved, and the four pixels of the four-quadrant detector are effectively utilized.

The application discloses a kind of shearing and carrier frequency independently adjustable common-path shearing interferometry imaging system and method, including coherent light source, the light beam of coherent light source is shot to the surface of measured object by beam expander, and measured object, lens one, diaphragm, lens two, Wollaston prism, polaroid, imaging lens, camera are sequentially arranged on the same axis with measured object.The application also discloses a kind of shearing and carrier frequency independently adjustable common-path shearing interferometry imaging method.The application uses the above-mentioned one kind of shearing and carrier frequency independently adjustable common-path shearing interferometry imaging system and method, the control of shear quantity and spatial carrier frequency in imaging system is distributed to different parts of imaging system, and adjustable near-zero shear quantity provides small enough shear force, to ensure that complex surface shape or deformation can be solved;When configuring the required near-zero shear quantity, the separate control of spatial carrier wave further ensures the well-distributed spatial spectrum.

The application provides a double optical path measurement system and method based on diffuse reflection, a Wollaston prism divides linearly polarized light into orthogonal polarized reference light and measurement light; the reference light returns through a reference mirror, the measurement light is focused to a rough surface of a sample to be measured through a second lens, and diffuse reflection echoes are collected and collimated back through the second lens. After the two-way return light is superimposed, polarized interference light is formed through a second polarizer. The transmission axis angle of the first and second polarizers is adjusted, the projection power ratio of the two-way return light is changed, and the working angle combination is determined according to the measured fringe contrast. A phase modulation mechanism drives the sample to be measured to generate a modulation displacement, a signal processing module carries out phase demodulation, phase unfolding and displacement conversion on the output of a photoelectric detector, and the axial relative displacement change between the reference reflection surface and the illuminated diffuse reflection effective area is obtained. The application can improve the problem of reduced interference fringe contrast caused by low diffuse reflection echo power and power mismatch of the two-way return light.

The present invention discloses a self-calibration measurement system and method applicable to the detection of lunar surface polarization spectral characteristics, belonging to the field of optical detection, including: along the propagation direction of incident light, a first achromatic quarter-wave plate, a multi-stage wave plate, a second achromatic quarter-wave plate, a beam splitting prism and two Wollaston prisms are sequentially arranged. The present invention uses the second achromatic quarter-wave plate, the beam splitting prism and two Wollaston prisms to form a polarization phase shift unit. After the incident light passes through the first achromatic quarter-wave plate and the multi-stage wave plate, the polarization information is modulated in the spectral dimension. The polarization phase shift unit shifts the modulated spectral phase by 0°, 180°, 90° and 270° to form two pairs of complementary modulated spectra. After the multi-stage wave plate is rotated by 90°, a secondary measurement is performed. The present invention can use the modulated spectra of the two measurements to extract the phase delay amount of the multi-stage wave plate in real time, and can solve the problem of the phase delay amount offset of the multi-stage wave plate caused by the temperature control fluctuation of the measurement system due to the large temperature difference on the lunar surface.

This invention discloses a laser interferometric device for simultaneous measurement of straightness and displacement that is insensitive to angular errors. It comprises an interferometric optical path and a measurement mirror assembly. The measurement mirror assembly consists of a Wollaston prism, a cornerstone prism, and a beam splitter, forming a moving measurement mirror. As this measurement mirror moves, it generates two measurement beams with different Doppler frequency differences. These beams are received by two photodetectors, outputting two measurement signals. These signals, along with a reference signal from a dual-frequency laser, are processed by a signal processing board and a computer to obtain the straightness error and displacement of the measured object. This invention achieves simultaneous measurement of straightness and displacement within a single laser interferometric device through the combination of the Wollaston prism, cornerstone prism, and beam splitter. By utilizing the insensitivity of the Wollaston prism and cornerstone prism to angular errors, the influence of the angular error of the measured object on the straightness error and displacement measurement results is reduced, thus improving measurement accuracy and stability.

The application provides a high-contrast polarization imaging system for direct imaging of exoplanets, which comprises a coronagraph system, a relay lens, a polarization modulation assembly based on phase modulation, an imaging lens and a detector. A polarimeter is introduced on the basis of the coronagraph system, a liquid crystal phase retarder is used as a modulation device, different intensity values are obtained by applying different voltages, and finally the Stoeks parameter is inverted. In view of the fact that the planet light has certain polarization characteristics and the star light has no polarization characteristics, the planet light can be distinguished from the star light after passing through the high-contrast polarization imaging system, and high-contrast polarization imaging is realized. Meanwhile, the system introduces a Wollaston prism to form a double light path, so as to reduce the influence of atmospheric turbulence, and meanwhile, additional contrast gain can be obtained, and an imaging contrast gain of about 100 times can be realized.