56 results about "Phase grating" patented technology

A sensor system for optical detection of multiple analytes is discussed. An example system is presented that includes a plurality of lenses configured to receive individual light signals from analyte-sensing chromophores disposed on an array when the analyte-sensing chromophores are illuminated by light while being exposed to different specific analytes within an interstitial fluid. The system further includes at least one volume phase grating (VPG) communicatively coupled to at least one of the plurality of lenses and a detector communicatively coupled to the at least one VPG so that light signals from the analyte-sensing chromophores are focused by the plurality of lenses to the at least one VPG and transmitted to the detector. The detector being operable to generate spectra with each spectrum corresponding to an individual light signal from a single analyte-sensing chromophore.

The invention discloses an infrared band optical frequency conversion element and a converter and a laser using the infrared band optical frequency conversion element, nonlinear optical polycrystalline transparent ceramic is adopted, and a processing area and an unprocessed area which are periodically and regularly distributed are arranged in the nonlinear optical polycrystalline transparent ceramic in the light passing direction. The refractive indexes of the processing area and the unprocessed area are different, so that a phase grating with periodically distributed refractive indexes is formed; the processing area is used for providing phase differences among the fundamental frequency light, the signal light and the difference frequency light, and the processing area does not have a nonlinear optical effect. Difference frequency laser output of an infrared band can be realized, and optical frequency conversion is realized in nonlinear optical polycrystalline ceramic by adopting a periodic phase adding method.

Advanced hologram techniques pre-calculate holograms to be displayed on an LCoS switch panel of a wavelength selective switch (WSS) module. The holograms are generated offline and are then stored on the WSS module for later retrieval. Each of the holograms is associated with a defined parameter, such as an attenuation level, and each of the holograms is configured to create a reconfigurable phase grating profile or pattern of the pixels of the LCoS switch panel. Each phase pattern selectively directs desired diffraction orders of optical channels from the LCoS switch panel for output to selected ports and selectively directs undesired diffraction orders away from the ports and at a desired attenuation level. During operation, the WSS module can retrieve the stored holograms. Interpolation can determine intermediate holograms between parameter values, and a ramp function can be added to the pattern to account for steering adjustments.

The present invention provides a reflective displacement measuring device, comprising: a projection system, an indicator grating, a reflective scale grating and a receiving system, wherein parallel light emitted by the projection system is incident on the indicator grating, and is incident on the surface of the reflective scale grating through the indicator grating, and then reflected back to the indicator grating to generate moiré fringes, which are projected to the receiving system and converted into electrical signals; the indicator grating comprises a glass substrate, a light-absorbing film is plated on the glass substrate, and a complex amplitude grating composed of an amplitude grating and a phase grating having only ±1-order diffraction fringes is etched on the light-absorbing film. The reflective displacement measuring device provided by the present invention can obtain an ideal light intensity distribution under the conditions of improving energy utilization and reducing the difficulty of manufacturing the grating.

The present disclosure provides a real-time holographic system and a real-time optical reconstruction method, which relate to the field of holographic technology. The system comprises: a first laser, adapted to generate nanosecond pulse light; a first beam splitter, adapted to split the nanosecond pulse light into reference light and detection light, the detection light being incident on an object to be measured and generating object light having information about the object to be measured; a reconstruction light timing module, adapted to generate reconstruction light having timed femtosecond pulse information; a dichroic mirror, adapted to generate combined light based on the incident reference light and reconstruction light; a holographic dry plate, adapted to receive the combined light and object light, so that the reference light and object light in the combined light interfere on the holographic dry plate to form a phase grating, thereby recording optical information; and a multi-frame imaging module, adapted to receive the reconstruction light and form a diffraction wave based on the phase grating, thereby reading the optical information with a time resolution of the order of picoseconds.

The present invention provides an optimization method for a grating structure to reduce position measurement errors, including: establishing an evaluation method for a phase grating structure according to the intensities of signals of different diffraction orders to describe the quality of the structure; then selecting one or more grating structures with better results as the initial grating structure according to this evaluation method; generating corresponding deformed grating structures according to the deformations that may be introduced during the manufacturing process; then comparing the above initial grating structure and the deformed grating structure to give multiple groups of grating arrangement combinations for comparison, and making plates for them to process a marked measurement plate for experiments; then establishing a corresponding relationship between the deformation of the grating structure and the introduced position error based on the comparison measurement results; and finally optimizing the initial grating structure according to this corresponding relationship to obtain an optimized grating structure. The optimized grating structure can offset or alleviate the influence of the deformation introduced during the manufacturing process on the position measurement accuracy and reduce the position measurement error.

The invention relates to the technical field of semiconductor measurement, particularly provides a system and a method for measuring a deep groove etching structure in a 3D NAND, and aims to improve a traditional CD-SAXS measurement unit, design a phase grating on a light path before probe light enters a measured sample, and measure the deep groove etching structure in the 3D NAND based on a Talbot effect and a fractional Talbot effect. The distance between the phase grating and a detected sample is designed to be a Talbot distance or a fraction Talbot distance, the phase grating modulates the detection light, so that the light intensity distribution of the detection light irradiated to the sample is in a light and dark stripe shape related to the grating structure period and the duty ratio, and then through an alignment mechanism, the light intensity distribution of the detection light irradiated to the sample is in the shape of light and dark stripes related to the grating structure period and the duty ratio. According to the method, light fringes of an incident light beam are aligned with a deep groove etching structure region in the 3D NAND to be detected, and dark fringes are aligned with a memory hole structure region, so that the intensity of light entering the deep groove etching structure part is enhanced, the intensity of light entering the memory hole part is weakened, and the difficulty of extracting a deep groove nano-structure scattering signal from a total scattering signal is reduced.

This invention discloses a quartz crystal Y-type optical beamsplitter capable of nonlinear frequency conversion in the deep ultraviolet band, belonging to the field of optoelectronic device technology. It includes a quartz crystal with a Y-type ridge waveguide structure on its surface. The Y-type ridge waveguide structure includes an input arm, the end of which is connected to the beginning of two branch arms. Each branch arm is connected to an output arm parallel to the input arm. One output arm contains a periodic phase grating structure arranged along the light transmission direction of the quartz crystal. The periodic phase grating structure is composed of several single-cycle femtosecond laser-modified regions and several unmodified regions arranged periodically. The Y-type optical beamsplitter disclosed in this invention integrates optical beam splitting and nonlinear frequency conversion functions, allowing for the low-loss output of both a fundamental ultraviolet beam and a deep ultraviolet frequency-doubled beam from an input fundamental ultraviolet light beam.

This invention discloses an infrared optical frequency conversion element and a converter and laser using the same. It employs a nonlinear optical polycrystalline transparent ceramic. The nonlinear optical polycrystalline transparent ceramic has periodically distributed processed and unprocessed regions along the light transmission direction. The processed and unprocessed regions have different refractive indices, forming a phase grating with a periodically distributed refractive index. The processed regions provide the phase difference between the fundamental frequency light, signal light, and difference frequency light, and these processed regions do not exhibit nonlinear optical effects. This invention enables difference frequency laser output in the infrared band by adding a periodic phase method to the nonlinear optical polycrystalline ceramic to achieve optical frequency conversion.

The application discloses a high-transmittance and high-uniformity geometric phase grating element prepared by using femtosecond pulse near-field normalization, a method and application thereof, and belongs to the technical field of laser processing. The application utilizes the principle of femtosecond laser pulse near-field normalization to perform uniform processing in fused quartz, induces a new type of high-transmittance and high-uniformity birefringence structure, controls the change of the slow axis direction, thereby preparing a high-efficiency geometric phase grating with adjustable period, and realizes edge detection by using the light splitting characteristics of the geometric phase grating. The application is applied to optical image edge detection by using an innovative processing technology, solves the limitations of a traditional birefringence structure in transmittance and uniformity, and provides a solution with better performance and lower cost for the field of optical image edge detection.

The invention discloses a radio frequency carbon dioxide laser fast switch control method based on acousto-optic modulation, which is applied to a radio frequency carbon dioxide laser and comprises the following steps: initializing system monitoring and parameter configuration; loading a driving signal to generate effective light; comprising the following steps: applying a driving signal to an acousto-optic modulator by using a control module, and exciting ultrasonic waves to form a phase grating in the acousto-optic modulator; enabling a laser beam output by the laser resonant cavity to enter the phase grating at a Bragg angle to form deflected effective light; outputting laser and performing feedback optimization; comprising the steps that laser is output, characteristic parameters of the output laser are monitored, and when it is monitored that the characteristic parameters of the current output laser are lower than target values of the characteristic parameters of the laser, a control module is used for selecting PID control to optimize driving signals; cutting off the driving signal and absorbing invalid light; comprising the steps that when laser output needs to be closed, a control module is used for stopping an acousto-optic modulator from applying a driving signal, and laser output is stopped. According to the invention, the requirements of high-precision and high-speed laser processing can be met.

A system for oblique incidence nanopatterning a sample using a grating beam-splitter is disclosed. The system also includes a grating beam-splitter on a tip-tilt adjustable mount. The system also includes a photoresist coated sample mounted on a tip-tilt-z adjustable mount. The system also includes an alignment system to allow adjustment of the tip-tilt adjustable mounts so that a surface of the grating beam-splitter and a surface of the photoresist coated sample are substantially parallel. The system also includes a laser operating at a wavelength suitable for exposure of the photoresist. The system also includes an optical system to deliver a laser beam at oblique incidence to the grating beam-splitter to expose the photoresist coated sample. The system also includes means to control an exposure dose of the laser beam. A system using two grating beam-splitters to provide increased alignment tolerance is also disclosed.

A system may include a lateral shearing interferometer. The lateral shearing interferometer may enable measuring a surface profile of a sample, such as the pattern wafers, using reflected light from the sample. The reflected light may be reflected at a grazing incidence angle. A controller may receive images from the lateral shearing interferometer and measure the surface profile. The controller may measure the surface profile by reconstructing a phase of the reflected light from the images. The controller may reconstruct the phase using spatial reconstruction or time-domain reconstruction. The gratings may allow the controller to measure the edge roll-off in one or two dimensions. The controller may also calibrate the grazing incidence angle and determine refractive indices of thin-films on the sample. The controller may also perform full measurements of the surface profile using line beams, rectangular beams, or full-sample beams.

The invention provides a real-time holographic system and a real-time optical reconstruction method, and relates to the technical field of holography, and the system comprises a first laser which is suitable for generating nanosecond pulse light; the first beam splitter is suitable for dividing the nanosecond pulse light into reference light and detection light, and the detection light enters an object to be detected and generates object light with information of the object to be detected; the reconstruction light time sequence module is suitable for generating reconstruction light with time sequence femtosecond pulse information; the dichroscope is suitable for generating combined light based on the incident reference light and the reconstructed light; the holographic plate is suitable for receiving the combined light and the object light, so that the reference light and the object light in the combined light interfere with each other on the holographic plate to form a phase grating, and optical information recording is realized; the phase grating is also suitable for receiving the reconstructed light and forming a diffraction wave based on the phase grating so as to realize reading of optical information with a time resolution of picosecond magnitude; and the multi-framing imaging module is suitable for receiving the diffracted waves to obtain a plurality of reconstructed images of optical information so as to realize real-time holography.

The present invention relates to the field of optical imaging technology, and specifically to a method for correcting chromatic aberration of a tomographic microscope, comprising the following steps: S1: adding a quadratic phase grating, a blazed grating, a reflector, and a tube lens to the imaging optical path of the microscope; wherein the blazed grating includes multiple parts corresponding to the diffraction orders of the quadratic phase grating; S2: placing the sample to be observed at the object-side focal plane of the microscope objective, and placing the quadratic phase grating at the image-side focal plane of the microscope objective; S3: incident light first passes through the microscope objective and then sequentially enters the quadratic phase grating, the blazed grating, the reflector, and the tube lens, and finally forms an image on a CCD detector; the light wave at the quadratic phase grating is split into three diffracted light waves and projected onto the upper, middle, and lower portions of the blazed grating, respectively, to achieve chromatic aberration correction through dispersion subtraction. The present invention has a simple structure, low manufacturing cost, good chromatic aberration correction effect, and high light wave projection energy.

The application discloses a continuous medium coherent array edge emitting semiconductor laser and a preparation method thereof. The laser comprises a conductive substrate, an epitaxial layer formed on the upper surface of the conductive substrate, a rear-end optical medium waveguide area and a front-end optical medium waveguide area located on both sides of the epitaxial layer. The upper surface of the epitaxial layer is provided with a one-dimensional array ridge waveguide area. A rear-end phase grating layer is etched on the rear-end optical medium waveguide area, and a front-end phase grating layer is etched on the front-end optical medium waveguide area. A P-face electrode is arranged on the upper surface of the one-dimensional array ridge waveguide area, an N-face electrode is arranged on the lower surface of the conductive substrate, a high-reflection film is arranged on the end surface of the rear-end phase grating layer, and an anti-reflection film is arranged on the end surface of the front-end phase grating layer. The laser of the application can realize in-phase mode lasing without the selection of supermodes by external optical elements, and the optical field has an ultra-narrow divergence angle in the slow-axis direction of the far field, so that the coupling efficiency of the array semiconductor laser and the optical fiber is greatly improved.

The invention relates to the technical field of semiconductor measurement, in particular to a 3D NAND measurement system and method, in an existing CD-SAXS measurement light path, a phase grating used for enhancing a scattering signal of a memory hole structure and a phase grating used for enhancing a scattering signal of a deep groove structure are designed on the basis of a Talbot effect or a fractional Talbot effect, and according to the measurement requirement, the phase grating used for enhancing the scattering signal of the memory hole structure and the phase grating used for enhancing the scattering signal of the deep groove structure are designed. A switching device is used for controlling and switching gratings in a measuring light path, detection light is modulated through a phase grating, the light intensity distribution of the detection light irradiated to a sample is in a light and dark stripe shape related to the grating structure period and duty ratio, then the bright stripes are aligned with an area needing to be detected according to an alignment mechanism, and the detection light intensity is adjusted. Dark fringes are aligned with areas needing to be filtered, so that separation and extraction of scattering signals of a memory hole structure and scattering signals of a deep groove structure are enhanced, and mutual interference of the two scattering signals is avoided.

The present invention relates to a photoelectron emitter (1) comprising a plurality of optical antennas (7), each antenna comprising a lateral radiating waveguide structure (10) formed by an input waveguide (11) and a lateral diffraction grating (12) configured to extract an optical mode in a horizontal plane, and a vertical radiating waveguide structure (30), the vertical radiating waveguide structure being formed by a radiating waveguide (31) configured to receive the optical mode extracted by the diffraction grating (12) and a vertical diffraction grating (32) configured to extract the optical mode traveling through the radiating waveguide (31) to free space.

The application discloses a two-dimensional array pulse self-synchronization wafer laser structure, which comprises an inner resonant cavity composed of a first reflecting layer, a saturable absorber, a wafer array gain medium and a second reflecting layer, and an outer resonant cavity composed of a phase grating structure layer and a third reflecting layer, and the inner resonant cavity and the outer resonant cavity form a composite resonant cavity; a pump light source emits pump light which is injected into the composite resonant cavity through a pump module, passes through the wafer array gain medium multiple times, and generates array oscillation laser in the inner resonant cavity; simultaneously, the saturable absorber absorbs and modulates the array oscillation laser, starts and maintains the array pulse operation; the array laser pulse enters the outer resonant cavity through the second reflecting layer, the phase grating structure layer causes the array pulse laser to be coupled, the array pulse laser returns to the inner resonant cavity through the third reflecting layer to be mutually injected, modulated and locked, the array pulse laser is synchronously operated in the composite resonant cavity, the collective mode laser pulse is formed, and the self-synchronized high-energy coherent array pulse output is realized.

A displacement phase modulator is provided for high power laser phase modulation processing, manufacturing and communication applications. In one embodiment, the displacement phase modulator includes multiple two dimensional (2D) modulators arranged in columns and rows on a substrate surface to form a array having multiple pixels along a longitudinal axis. Each pixel includes multiple 2D modulators in one or more adjoining columns and has a long axis transverse to the longitudinal axis of the array. The 2D modulators in each pixel are electrically coupled to receive a common input signal and to operate in unison to modulate a phase of light reflected therefrom in response to the input signal. In some embodiments, the 2D modulators include a faceplate with raised elongated reflective elements to form a blaze profile or a phase grating, operable to diffract an incident light into at least two diffraction orders. Other embodiments are also disclosed.

The application discloses a single-phase grating X-ray microscopic imaging system based on two-stage amplification, which comprises a geometric amplification system, an optical amplification system and a detector; the geometric amplification system comprises an X-ray light tube, a plurality of capillary tubes, a phase grating and a scintillator; the optical amplification system amplifies a fluorescent signal to obtain a fluorescent amplified signal, separates the fluorescent amplified signal from a first modulation signal, and obtains the fluorescent amplified signal; and the detector receives the fluorescent amplified signal. The application uses the plurality of capillary tubes to focus X-rays to realize geometric amplification, uses a scintillator coupled lens imaging system to realize optical amplification, uses two-stage amplification to realize high-resolution microscopic imaging, realizes high resolution without relying on a high-coherence X-ray beam, uses the light source segmentation characteristics of the plurality of capillary tubes, uses only one phase grating to modulate an object, acquires multi-modal information, and does not need two absorption gratings required by a traditional X-ray phase contrast system, thereby greatly improving system light flux and imaging contrast.

In a wavelength selective switch, an input port transmits an input beam, and diffraction grating disperses the input beam into optical channels. A liquid-crystal-on-silicon (LCoS) switch assembly has a phase grating profile and has addressable pixels, which are liquid crystal based. The LCoS switch assembly can selectively direct first-order diffracted beams of the optical channels for output to selected output ports. A tunable optical wedge adjacent the LCoS switch assembly can direct higher-order diffraction beams in the space between the output ports to reduce crosstalk. The wedge is a liquid crystal cell having spaced-apart resistive layers and having liquid crystal material disposed between the layers. In the wedge, the liquid crystal material can produce a phase profile in response to bias voltages applied to the resistive layers, and a beam steering angle of the phase profile can direct at least the second-order diffracted beams towards the port spacing between the ports.

The application discloses an optical diffraction tomography imaging device and method based on an integrated quantitative phase imaging camera, and mainly solves the technical problems of mechanical vibration, poor stability, low measurement precision, limited imaging field of view and the like of the current optical diffraction tomography device. The application realizes multi-angle rotary illumination without mechanical movement by loading a blazed phase grating with different directions and periods of pixel numbers on a reflective liquid crystal spatial light modulator; uses the integrated quantitative phase imaging camera to record the point array interference diagram of a non-marked transparent sample under different illumination angles, then processes the four-wave shearing interference point array diagram by using a Fourier transform method, and inversely calculates the light field complex amplitude distribution of the sample under different illumination angles; finally, based on the optical diffraction tomography principle, the three-dimensional refractive index distribution of the sample is quantitatively reproduced from the obtained multi-angle complex amplitude sequence, the micro three-dimensional structure distribution inside the transparent sample is observed without marking, and high-precision three-dimensional imaging is realized.

The application discloses a preparation method of a reflective curved fork surface grating. The grating prepared by the method is a pure phase grating and can be used for generating perfect vortex light (POV). A high-order Bessel Gaussian beam is interfered with a Gaussian beam to expose a photosensitive material on a substrate, wherein the high-order Bessel Gaussian beam is generated by a reflective pure phase liquid crystal spatial light modulator (SLM), and after development and metal film plating, the reflective curved fork surface grating is prepared. When a Gaussian light of a base mode is used for irradiation, the POV can be obtained on a far field or a lens focal plane in a first-order diffraction direction. The method for obtaining the POV by using the reflective curved fork surface grating has the advantages of a higher damage threshold, a wider working wavelength range and a higher conversion efficiency, and has the advantages of simple structure, low cost and mass production, and has an important prospect in generation of high-power POV and can be used in the fields of optical manipulation and optical processing.

The invention provides a panoramic desktop naked-eye 3D display system. The panoramic desktop naked-eye 3D display system comprises a collimation light source, a two-dimensional image display screen, a directional view angle modulator and a phase grating group. The collimation light source is used for providing collimation illumination light; the two-dimensional image display screen is used for loading a two-dimensional multi-view synthetic image in naked eye 3D display; the directional view angle modulator is used for separating a two-dimensional multi-view-angle image and is composed of multiple groups of pixelated nano-gratings, one group of pixelated nano-gratings is used for constructing a convergence view angle, multiple groups of pixelated nano-gratings construct multiple convergence view angles, and a space view angle image required by naked eye 3D display is formed through combination. The phase grating group is formed by splicing a plurality of phase gratings along a closed loop and can be spliced into any polygon, a single phase grating can copy a convergent view angle in different diffraction order areas through grating diffraction, the convergent view angle is expanded to form annular view angle distribution through the combination of the plurality of phase gratings, and the convergent view angle can be distributed in different diffraction order areas under the limited number of view points. And a high-quality panoramic desktop naked-eye 3D display effect is obtained.

The application relates to the field of semiconductor measurement technology, and particularly provides a system and method for measuring a deep trench etching structure in a 3D NAND, aiming at improving a traditional CD-SAXS measurement unit, designing a phase grating on an optical path before probe light is incident on a measured sample, and based on Talbot effect and fractional Talbot effect, the distance between the phase grating and the measured sample is designed as Talbot distance or fractional Talbot distance; the probe light is modulated through the phase grating, so that the probe light intensity distribution irradiated to the sample presents a bright and dark stripe distribution related to the grating structure period and duty cycle; then, through an alignment mechanism, the bright stripe of the incident light beam is aligned to the deep trench etching structure region in the 3D NAND to be measured, and the dark stripe is aligned to the memory hole structure region, so that the light intensity incident to the deep trench etching structure part is enhanced, the light intensity incident to the memory hole part is weakened, and the difficulty of extracting the deep trench nanostructure scattering signal from the total scattering signal is reduced.

The invention provides a pre-deflection angle adjusting wavelength selection switch device and a use method, the pre-deflection angle adjusting wavelength selection switch device comprises a light receiving and transmitting end, a grating assembly, a deflection element, a phase grating and a light switching engine which are sequentially arranged along a light path, and a transmitting end emergent light signal in the light receiving and transmitting end is received by the grating assembly and is divided into a plurality of light signals with different wavelengths; the optical signals with different wavelengths are emitted to the phase grating through the deflection element, and the deflection angles of the optical signals with different wavelengths are changed through the deflection element, so that the grating periods corresponding to the optical signals with different wavelengths are consistent; a phase grating on the light switching engine divides each light signal with different wavelengths into diffracted light of different times, the diffracted light is returned to a light receiving and transmitting end along a light path, and part of the diffracted light of a preset level is received by a corresponding receiving end in the light receiving and transmitting end; the grating periods corresponding to the optical signals with different wavelengths are consistent, so that the diffracted light with different wavelengths and the same level converges, and crosstalk caused by divergence of the diffracted light with the same level is avoided.

The invention provides a multi-view-field display. The multi-view-field display comprises a display module, a circular polarization module and an interrogation Latrinamm-Beryer phase grating. The display module is used for providing initial display light with linear polarization. The circular polarization module is used for adjusting initial display light from the display module into first circularly polarized light and second circularly polarized light. The interrogation Latrinamm-Beryer phase grating is disposed in front of the circular polarization module and includes a liquid crystal material. And the alignment orientation of the liquid crystal material is periodically changed along the light splitting direction to form a plurality of grating units. The interrogation Laynaum-Beryer phase grating adjusts the first circularly polarized light and the second circularly polarized light into first display light emitted towards the first light emitting direction and second display light emitted towards the second light emitting direction. The first light-emitting direction and the second light-emitting direction are diverged relative to each other in the light splitting direction.

A wavelength selective switch apparatus with pre-tilt angle adjustment, and a method for using same. The apparatus comprises a optical transceiving end (1), a grating assembly (2), a deflection element (3), a phase grating (4) and an optical switching engine (5), which are sequentially arranged along a optical path, wherein an optical signal emitted by a transmitting end (11) in the optical transceiving end (1) is received by the grating assembly (2) and divided into a plurality of optical signals of different wavelengths, the optical signals of different wavelengths are transmitted to the phase grating (4) through the deflection element (3), and tilt angles of the optical signals of different wavelengths are changed by means of the deflection element (3), such that the optical signals of different wavelengths correspond to the same grating period; and the phase grating (4) on the optical switching engine (5) divides each of the optical signals of different wavelengths into diffracted light of different orders, and returns same to the optical transceiving end (1) along the optical path, wherein some diffracted light of a preset order is received by a corresponding receiving end (12) in the optical transceiving end (1). Since optical signals of different wavelengths correspond to the same grating period, diffracted light of the same order but different wavelengths converges, thereby preventing crosstalk caused by divergence of the diffracted light of the same order.

The invention belongs to the technical field of metal fatigue and plastic deformation process detection, and particularly relates to a metal fatigue and plastic deformation process laser ultrasonic detection system and a detection method thereof. Comprising a laser ultrasonic signal excitation assembly, a laser ultrasonic signal detection assembly and a to-be-detected sample detection platform, the laser ultrasonic signal excitation assembly comprises a pulse laser, a phase grating and a 4F optical modulation unit; the laser ultrasonic detection assembly comprises a continuous laser, a double-wave mixing interference unit, a signal acquisition and processing unit and a lambda wave plate group; the to-be-detected sample detection platform comprises a 360-degree rotating table for realizing rotation of a to-be-detected sample and a two-dimensional scanning translation table for realizing translation of the to-be-detected sample. According to the invention, laser is irradiated on the detected workpiece, ultrasonic waves are generated based on a thermoelastic theory, contact with the detected workpiece is not needed, and non-contact measurement can be realized, so that a residual stress testing environment of a high-temperature, corrosive and radiated alloy material is met.