202 results about "Laser interference" patented technology

The invention relates to the technical field of length measurement, and particularly discloses a length measurement device based on laser interference, which comprises a laser measurement module, an air curtain channel module, an air curtain construction module and a channel adjustment module, the laser measuring module is used for transmitting and receiving laser, the optical path difference change is measured according to the interference principle, and the micro length change of the workpiece can be continuously and accurately measured in real time while the machining module carries out machining operation on the workpiece; a linear channel is formed between the laser head and the measuring reflector through the air curtain channel module, inert gas is continuously introduced into the channel through the air curtain construction module, and an air curtain atmosphere with stable laminar flow is formed, so that pollutants and interference factors such as oil mist, dust, cutting fluid splashing and hot air turbulence generated in a machining area are effectively blocked, and the machining precision is improved. Therefore, the measurement light beam is prevented from being interfered by environmental factors in the propagation process.

The invention discloses an automobile wire harness detection device based on artificial intelligence and machine vision, and relates to the technical field of visual inspection, and the device comprises a film covering module which enables an automobile wire harness to be immersed in a control groove of magnetic fluid to form a nano film; the marking module projects interference fringes to the nano-film through a laser interference projector, and marks timestamps and capture numbers of fringe images; the image module is used for applying magnetic field pulses in the timestamps of the adjacent stripe images to generate a turbulent flow image sequence; the quantization module is used for respectively carrying out interference fringe phase analysis on the turbulence images in the turbulence image sequence to generate a curvature quantization matrix; the defect module is used for analyzing the curvature quantization matrix through a pre-trained convolutional neural network and identifying a defect type and a coordinate position; and the result module is used for superposing the defect type and the coordinate position to the stripe image to generate a defect distribution thermodynamic diagram. According to the invention, high-precision intelligent defect identification of wire harness detection is realized through cooperation of the nano-film and the convolutional neural network.

The invention relates to the field of wafer defect detection, in particular to a rapid zooming wafer detection microscope based on MEMS and a detection method. The microscope comprises an illumination part, a sample stage, a spectroscope, a microscope objective, an MEMS micromirror array zoom module, a CMOS image sensor, a laser interference distance measuring sensor and a synchronous control and processing module based on an FPGA. The MEMS micro-mirror array zoom module composed of a plurality of micro-mirror units is introduced into a light path, the deflection state of each micro-mirror unit is adjusted, a dynamic reflecting surface with a controllable equivalent curvature is formed, focusing regulation and control of imaging light beams are achieved, electronic focusing without mechanical movement is completed, the response speed is superior to that of traditional mechanical adjustment, and the imaging quality is improved. And the method is suitable for high-speed online detection.

The application relates to the field of detection devices and discloses a high-precision gas bearing static characteristic test table, which comprises an optical base, a detection table arranged on the optical base, a suspension support arranged on the optical base, a detection cylinder arranged on the suspension support and located directly above the detection table, a gas floating ball hinge arranged at the driving end of the detection cylinder, a pressure sensor arranged at the bottom of the gas floating ball hinge, and an upper floating bearing plate arranged at the bottom of the pressure sensor and used for being pressed on the detection table. A laser interference measurement assembly is arranged between the lower surface of the upper floating bearing plate and the upper surface of the optical base and used for measuring the displacement and inclination of the lower surface of the upper floating bearing plate. The application can accurately evaluate the partial static characteristics of the gas bearing.

The invention relates to the technical field of semiconductor etching, in particular to a semiconductor etching method based on plasma coordinated regulation, which comprises the following steps: alternately using first plasma and second plasma on a semiconductor to be etched to obtain a plurality of groove structures with a preset depth-to-width ratio, the second plasma is used for cleaning side wall residues; detecting by using a laser interference measurement method to obtain an etching rate ratio and a side wall angle corresponding to each groove structure, and determining corresponding treatment according to the change condition of the etching rate ratio and the side wall angle, including maintaining the etching and cleaning parameters of the current stage, or adjusting the corresponding parameters of the first plasma according to the need, or corresponding parameters of the second plasma are adjusted according to needs. According to the method, the first plasma and the second plasma are cooperatively controlled to adjust the groove structure in each stage, so that the uniformity of the groove structure is improved, and the damage to the surface of the side wall is reduced.

The invention belongs to the technical field of image processing, and particularly relates to a GIS shell girth welding deviation real-time correction method which comprises the steps that a target image and a target image sequence are obtained; positioning a laser region according to a pixel point gray value interval and a pixel point brightness concentration condition in the target image to obtain a laser region sequence; forming a laser centroid sequence by taking the exponential power of the gray values of the pixel points in the laser area as a weight; smoothing the laser centroid sequence to obtain a smooth track point, and generating a laser actual motion track; smoothing the actual movement track of the laser to generate a reference welding track; calculating a real-time correction vector according to the reference welding track and the actual laser motion track; and according to the real-time correction vector and the welding reference position in the reference welding track, a new target position is calculated, the position of a welding head is adjusted, and real-time correction of the welding deviation is achieved. The problem that deviation correction is inaccurate due to the fact that the GIS shell girth welding process is interfered by laser is effectively solved.

The invention discloses a wire bonder transducer, a wire bonder and a vibration amplitude detection and calibration method, and realizes non-contact and high-sensitivity amplitude detection of a vibration part of the transducer by integrating a laser interference detection part in the wire bonder transducer. Continuous laser with a stable wavelength is output through the laser, signal light and reference light are split through the optical splitter, the signal light irradiates the vibration part of the transducer and is reflected, the reference light and the reflected light are combined in the beam combiner to form interference fringes, and finally a phase change signal is collected through the photoelectric detector. According to the invention, the micron-sized vibration displacement of the transducer in the working state can be extracted in real time with high precision. Compared with a traditional judgment mode, the method has the advantages that an objective and quantifiable detection means is provided, the precision and the automation degree of transducer performance consistency evaluation are effectively improved, the method can be widely applied to production line detection, equipment calibration, online quality control and other scenes of wire welding equipment, and the method has important significance in guaranteeing the welding stability and improving the packaging yield.

The invention relates to the technical field of position control feedback, and particularly provides a laser interference feedback positioning system and a positioning method thereof, and the system comprises a wave source phase modulation subsystem, a dynamic path compensation subsystem and a multi-dimensional feedback calibration subsystem. The method comprises the following steps: establishing a dynamic phase encoding model through nonlinear time sequence analysis; an original fixed phase beam of a laser wave source is converted into a tuning beam with space-time correlation, and a phase characteristic matrix of the tuning beam is used as an input parameter of a dynamic path compensator; constructing a compensation field model based on the tuning beam phase feature matrix; generating a dynamic compensation gradient by using the phase characteristic matrix; integrating the dynamic compensation gradient and the environment sensing data of the laser wave source, and constructing a six-dimensional state space calibration model; and outputting comprehensive positioning parameters including the displacement vector, the confidence interval and the environmental stability coefficient. Static measurement of a traditional interferometer is converted into an active regulation and control process with high adaptability and controllable errors.

The invention discloses a ship sheet welding part deformation monitoring method and system. According to the method, controllable elastic disturbance is introduced into a welding area through a phased array sound wave excitation module, and tiny response of the surface of a welding part under the action of thermal stress is excited; a multi-frequency interference light intensity image of a welding area is obtained through a laser interference measurement module, phase responses under all sound wave frequencies are extracted through Fourier spectrum analysis, and a multi-frequency comprehensive disturbance amplitude graph is obtained; and in combination with temperature gradient information acquired by the thermal infrared imager, a disturbance direction vector field is constructed, and then a two-dimensional disturbance vector field of the welding area is generated. An abnormal deformation area possibly generated in the welding process is recognized in real time by constructing a judgment early warning mechanism, and visual early warning information is output. The method has the technical characteristics of non-contact, high precision, real-time performance and multi-dimensional cooperation, and is suitable for intelligent deformation monitoring and early risk early warning in the ship thin plate component welding process.

The invention provides a fiber laser interference vibration measurement method and device, and relates to the technical field of fiber laser interference vibration measurement. The laser is divided into reference light and measuring light through the 1 * 2 coupler, the measuring light is divided into multiple paths through the 1 * N coupler, the multiple paths of light are irradiated to the same measuring point from multiple directions through the circulator and the collimation / focusing optical element, a redundant light return channel is constructed, and the light return success rate and interference stability under a rough surface or a curved surface or a diffuse reflection surface are effectively improved. The return light and the reference light are superposed in the interference unit to form interference fringe signals, high-precision vibration displacement data are extracted through signal detection and three-phase demodulation, and the method is suitable for non-contact vibration measurement scenes which are low in cost and easy to deploy.

The invention relates to the technical field of nondestructive testing of constructional engineering, and discloses a laser measuring instrument for nondestructive testing of concrete cavities, which comprises a laser interference measuring assembly, a paraxial sound wave excitation assembly, coaxially arranged anti-interference equipment and a cooperative control processing system. The sound wave excitation assembly performs wide-area excitation on the concrete surface, and the laser interference measurement assembly receives returned light through a clean light path constructed by the anti-interference equipment. The cooperative control processing system establishes acousto-optic time-frequency association by using an adaptive control module, generates a phase compensation angle according to ranging data to eliminate phase lock loss caused by sound wave propagation delay, and monitors a spectral gradient to automatically trigger fixed-frequency locking to capture resonance response. And the signal analysis module uses the phase compensation correction signal, and outputs cavity features through dual data cleaning and thermodynamic diagram analysis. According to the invention, the problems of time-space synchronization and weak signal extraction of long-distance non-contact detection in a complex environment are effectively solved.

The invention discloses a nano-scale displacement real-time compensation measurement method and system based on double-frequency laser interference, and belongs to the technical field of precision measurement. In order to solve the problems that three error sources of environmental drift, periodic nonlinear error and dynamic vibration are mutually coupled and have high real-time requirements in dual-frequency laser interference measurement, a multi-source error unified state space model including measured displacement, an air refractive index parameter, a nonlinear error parameter and a vibration disturbance quantity is constructed. A high-dimensional state vector is divided into a displacement-refractive index group and a nonlinear parameter group by adopting an extended Kalman filter of a grouping updating strategy, the displacement-refractive index group and the nonlinear parameter group are alternately updated in an assembly line parallel mode, nonlinear parameters are identified in real time in combination with an online recursive least square algorithm, and the state of the filter is corrected through a state coupling injection mechanism. Real-time compensation with the end-to-end delay smaller than 80 microseconds is achieved, the displacement measurement residual error is controlled within + / -0.3 nm under the composite disturbance condition, and the method is suitable for precise assembly of intelligent glasses optical assemblies.

The invention relates to the technical field of semiconductor thickness measurement, in particular to a VCSEL epitaxial wafer thickness measurement method based on laser interference. The method comprises the steps that a self-adaptive band-pass filter is constructed for any effective measurement point, the center frequency of the self-adaptive band-pass filter is the correction frequency center of the effective measurement point, and the bandwidth of the self-adaptive band-pass filter is inversely proportional to the local quality factor of the effective measurement point; and filtering the initial frequency spectrum of each measurement point by adopting a self-adaptive band-pass filter, and calculating the thickness of the epitaxial wafer based on the filtered frequency spectrum. Through a self-adaptive filtering strategy, frequency spectrum drift and deformation can be effectively compensated, so that the thickness of the epitaxial wafer is calculated more accurately, and the accuracy and stability of epitaxial wafer measurement are improved.

The invention relates to a laser interference surface type measurement method using random mechanical disturbance for resolving. The method comprises the following steps: acquiring an interference image of a measured element by using a surface type measurement device based on laser interference; applying random mechanical disturbance to the surface type measuring device to cause the change of the relative pose between the reference mirror and the measured element so as to acquire N frames of interference images in different disturbance states; and processing the acquired interference images through a natural phase decoding algorithm to obtain the surface topography of the measured element. Compared with the prior art, high-precision measurement of the surface type of the measured element can be realized without vibration isolation equipment and a high-precision phase shifter, and the method has the advantages of low cost, low system complexity and high adaptability.

The invention discloses a BNCT target disc temperature detection system and method. The method comprises the steps that a magneto-optical film with the thickness of 20 + / -1 nm grows on the back surface of a rotating lithium target through magnetron sputtering; a dual-wavelength laser interference light source is introduced into a vacuum target chamber through a coaxial optical fiber probe to form a dual-cavity interference link; the magneto-optical film generates nanoscale displacement by using centrifugal force generated when the rotary lithium target rotates, so that the instantaneous temperature rise of the rotary lithium target is amplified into a phase polarization composite signal capable of being optically detected; the integrated micro slip ring coupling optical path is used for coupling the phase polarization composite signal to a static end photoelectric detector; a phase polarization composite signal output by the photoelectric detector is input into the field programmable gate array, and the transient micro-area temperature field of the rotating lithium target is solved in real time; and the generated transient micro-area temperature field is used as a boundary condition for driving, so that closed-loop verification and temperature control protection of the rotating lithium target are realized. According to the invention, millisecond-level temperature control protection of the ultrathin rotary lithium target can be realized.

The invention provides a laser interference coding image restoration optimization method, and belongs to the technical field of photoelectric imaging in image processing. According to the method, comprehensive optimization of image quality is realized through directional search and removal of light spot noise, restoration of coding information and restoration of background information.

The invention discloses a spacecraft micro-deformation measurement method and system based on femtosecond laser interference, and relates to the technical field of laser interference measurement, and the method comprises the steps: extracting an interference phase signal corresponding to residual distribution, obtaining frequency domain representation through fast short-time Fourier transform, and calculating the spectral intensity; performing frequency domain decomposition on the spectral intensity by using a Laplacian pyramid, calculating local energy density and performing normalization processing to obtain a scale weight, converting residual distribution into a frequency domain deformation spectrum through Fourier transform, and performing weighted fusion in combination with the scale weight to generate a fusion deformation field; the measurement precision and real-time performance in a complex environment are improved by accurately controlling the optical main axis, temperature compensation and interference fringe analysis, deformation field information can be accurately extracted by combining the Laplacian pyramid and the frequency domain fusion technology, and the measurement sensitivity and accuracy are improved.

The invention discloses automatic intelligent production equipment for a water hammer valve, belongs to the technical field of production of water hammer valve accessories, and solves the problems that visual detection depends on a surface form and cannot directly judge an internal combination state, so that missing detection is easily caused, the bearing capacity of a welding seam is obviously reduced due to incomplete fusion, and brittle fracture is possibly caused under the impact of a water hammer. Comprising a welding mechanism, a cooling channel, a defect recognition mechanism and a discharging mechanism which are sequentially arranged, the defect recognition mechanism is coupled with the discharging mechanism, and the defect recognition mechanism collects acoustic response of a welding seam in real time by synchronously exciting ultrasonic waves, electromagnetic eddy currents and a laser interference field. A welded water hammer valve guide rod and a piston can be cooled and then moved to the position below the defect recognition mechanism, multi-physical-field characteristics are collected by synchronously exciting ultrasonic waves, electromagnetic eddy currents and a laser interference field to recognize weld defects, then the discharging mechanism is controlled to take out defective parts, and the product quality is ensured.

The invention discloses a high-efficiency laser interference transmit-receive color separation film with good space environment tolerance, which belongs to the technical field of optical thin films and is characterized in that a multifunctional beam splitting film is plated on the front surface of a fused quartz substrate, and a thermal stress compensation-free antireflection film is plated on the back surface of the fused quartz substrate. A front film system adopts TiO2 and SiO2 as high and low refractive index materials, and a main film system based on a rear cut-off filter superposed multi-layer energy regulation and control structure is designed, so that efficient reflection of 1550 + / -10nm laser is realized; and a half-wave hole is eliminated by matching an asymmetric equivalent layer, so that neutral light splitting at the wave band of 750-900nm is realized. The back film is composed of Ta2O5 and SiO2, so that the residual reflection (ghost image) is efficiently eliminated, and the surface distortion caused by the front film layer is compensated. The laser interference transmit-receive color separation film is good in spectrum stability, can tolerate a severe environment directly exposed in a geostationary orbit, and can also be used for spectrum and energy regulation and control of other laser ranging cameras.

The present application belongs to the field of photoelectric countermeasure simulation and digital twin technology, and relates to a laser jamming full-link digital parallel simulation system and method. The system comprises a scene initialization unit, a laser parameter configuration unit, a target characteristic definition unit, an atmospheric transmission calculation unit, a load imaging simulation unit, a jamming effect evaluation unit and a visualization terminal connected in sequence. The method realizes digital simulation of the whole process of laser jamming through the whole process coupling of scene configuration, atmospheric transmission calculation, load imaging simulation, jamming effect evaluation and visualization output. The present application solves the problems of lack of full-link integration, insufficient dynamic process simulation, weak semi-physical verification capability and poor scalability in the prior art by constructing a full-link integrated simulation architecture covering ground radiation, atmospheric transmission, load imaging and image quality evaluation, and can be widely applied to photoelectric countermeasure equipment effectiveness evaluation, countermeasure strategy optimization and equipment performance verification.

The application discloses a wafer polishing laser interference closed-loop pressure control method, and relates to the technical field of semiconductor manufacturing, and comprises the following steps: S1: a ceramic plate is triggered to automatically measure a program after being turned over with a wafer; S2: a laser interference measurement head is driven by a six-axis mechanical arm positioning system to non-contact scan T2 / T4 points of the wafer, and thickness distribution data is acquired; S3: a Zernike polynomial is adopted to fit the thickness distribution data to generate a three-dimensional distribution graph, and a pressure correction amount is calculated based on a pressure prediction model constructed by a process kinetics model and a support vector machine regression algorithm; S4: an abnormal processing module is used to detect data outliers in real time, and a device protection strategy is triggered when a deviation exceeds a set threshold; and S5: a pressure control instruction is transmitted to a polishing head by a PLC controller through a PROFINET bus. By means of non-contact laser interference measurement, the laser interference technology is applied to wafer thickness detection after polishing for the first time, and single measurement time is less than 20 seconds, so that the detection efficiency is significantly improved.

The invention discloses a laser interference measurement system comprising a suspension type workpiece table, a vacuum cavity comprises a cavity body and a cavity cover, the top of a suspension cavity is connected with the inner side of the cavity cover, so that the suspension cavity is suspended in the vacuum cavity, and the workpiece table is arranged in the suspension cavity; the laser is located outside the vacuum cavity and installed below one side of the cavity cover, and a light conversion mirror is installed in the light emitting direction and used for steering laser to be emitted into the cavity. A vacuum window is arranged on the side wall of the cavity, the spectroscope and the interference mirror are both located in the cavity and installed on one side of the upper portion of the suspension cavity, and the reflective mirror is located in the suspension cavity and installed on the workpiece table. The laser passes through the vacuum window, reaches the spectroscope, passes through the interference mirror and then is emitted to the reflective mirror on the workpiece table. According to the invention, the outer-layer cavity is used for providing a vacuum environment, the inner-layer cavity is used for providing a supporting effect, and the workpiece table and the measuring lens group are designed on the inner-layer cavity, so that the influence of vacuum deformation on a measuring light path is greatly eliminated.

The invention belongs to the technical field of laser interference precision measurement, and provides a full geometric error displacement calculation method based on non-approximate simplification of a light beam track. All optical machine geometric errors can be completely calculated, the real refraction condition can be completely calculated, no approximate error is introduced in the simplification process, and the displacement calculation process conforms to the real light beam track condition; according to the method provided by the invention, all reflection phenomena in the interferometer are simplified, parameter integration is carried out on a reflecting surface and a receiving surface of a reflected light beam, an originally complicated multi-beam calculation process is optimized, the number of parameter items required for completely describing geometric errors is reduced, and the calculation efficiency is improved. And meanwhile, the light beams which do not influence the calculation of the total optical path difference are deleted, so that the calculation efficiency is high.

This invention discloses a high-efficiency laser interferometric transceiver dichroic film with good space environment tolerance, belonging to the field of optical thin film technology. The dichroic film has a multifunctional beam-splitting film deposited on the front side of a fused silica substrate, and a thermal stress-free antireflection film deposited on the back side. The front film system uses TiO2 and SiO2 as high and low refractive index materials, and is designed with a main film system based on a back-cutoff filter superimposed with a multi-layer energy control structure to achieve efficient reflection of 1550±10nm laser light; and eliminates half-wave apertures by matching asymmetric equivalent layers to ensure neutral beam splitting in the 750-900nm band. The back film system is composed of Ta2O5 and SiO2, which not only efficiently eliminates residual reflections (ghost images) but also compensates for surface distortion caused by the front film layer. This laser interferometric transceiver dichroic film exhibits good spectral stability and can withstand the harsh environment of direct exposure to geostationary orbit. It can also be used for spectral and energy control of other laser rangefinders.

The present application relates to the technical field of spectral analysis, and particularly relates to a Fourier spectrometer and a control method thereof. The Fourier spectrometer provided by the present application comprises a control unit, a light receiving unit, a first detection unit, a second detection unit, an interference unit and a delay unit with a rotating structure. The second detection unit is used for sequentially inputting a laser signal to the interference unit and the delay unit to obtain a laser interference signal, and outputting the laser interference signal to the control unit to obtain a sampling clock signal, which is used for controlling the sampling frequency of the interference signal. The present application introduces the second detection unit and the delay unit with the rotating structure, so that the sampling process of the spectrometer can be more flexibly controlled, and the accuracy and efficiency of the sampling are improved. By accurately controlling the change of the optical path difference, the resolution of the spectral data is improved, which is helpful for more accurately analyzing the spectral characteristics of the sampling light.

The invention relates to a structural design method of an eccentric cradle body of a cradle rotary table for a five-axis machine tool, which is characterized in that the eccentric direction is opposite to the rotating direction through the eccentric design of the cradle body structure, so that the tooth surface on one side of a worm gear is tightly attached to the tooth surface on one side of a worm; therefore, the problem of unstable precision of the rotary table inclined shaft caused by a worm and gear gap is solved. The invention relates to a method for identifying structural parameters of an eccentric cradle body by mainly combining simulation analysis and a multi-objective optimization algorithm. The method comprises the following steps: firstly, constructing a multi-body dynamic model in Adams, obtaining a transmission error and jitter curve through torque scanning, and identifying an optimal input torque interval; and finally, importing the optimized box body model into Adams for coupling simulation verification, and calibrating the simulation model in combination with a laser interference experiment. The method is suitable for various high-precision machine tools, in particular to the field of five-axis machine tool machining requiring high precision and high dynamic performance.

The application discloses a laser interference detection parameter adaptive control method based on reinforcement learning, comprising the following steps: obtaining relevant data to form an interference state vector, and constructing an interference optical physics model and a safety constraint model; constructing a sub-target generation unit to generate a target optimization direction set; constructing a hierarchical reinforcement learning structure to output an adjustment control quantity sequence of a detection parameter; constructing an external reward generation unit and an internal reward generation unit, introducing a reward consistency mapping unit to correct the internal reward, and generating an updated hierarchical reinforcement learning structure; periodically updating the interference state vector to realize a laser interference detection parameter adaptive control closed loop. The application utilizes hierarchical reinforcement learning to combine optical physics and safety constraint modeling, realizes adaptive optimization control of a laser interference detection parameter, and has the advantages of high measurement precision, high intelligent degree of parameter adjustment, and safe and stable operation.

The invention discloses a micro-lens array non-scanning type laser interference three-dimensional imaging method and device for a dynamic sample, and relates to the technical field of optical three-dimensional measurement and imaging, and the method comprises the steps: dividing laser into object light and reference light; irradiating a dynamic sample arranged at the focal plane of the micro-lens array with the object light after beam expansion, modulating the object light carrying sample information by the micro-lens array, and combining the modulated object light with the reference light in space to generate a composite interference field containing a plurality of sub-region interference patterns; recording a single-frame composite interferogram by an area array detector; and finally, reconstructing the three-dimensional morphology of the sample at the measurement moment through a phase extraction and unwrapping algorithm. By means of the mode, full-view-field three-dimensional information can be obtained through single exposure by means of the microlens array, mechanical scanning or multi-frame phase shifting is not needed, the problem of motion artifacts generated when a dynamic sample is measured through a traditional interference method is effectively solved, and high-speed and high-resolution three-dimensional imaging of the surface appearance of the dynamically-changed sample is achieved.

The invention discloses a focus-adjustable laser interference end point detection device. The focus-adjustable laser interference end point detection device comprises a detection main body, the light source module is used for emitting detection light and / or illumination light; the focusing lens comprises a first lens group, a focusing group and a second lens group which are arranged in the detection main body; the focusing group and the second lens group are movably arranged in the detection main body along the vertical direction; detection light rays and / or illumination light rays emitted by the light source module pass through the first lens group and then are reflected by the first reflector group to enter the focusing group, pass through the focusing group and then are reflected by the second reflector group to enter the second lens group, and pass through the second lens group and then are focused on the surface of a wafer. The imaging unit is used for recording and outputting image information of the surface of the wafer; and the adjusting part is arranged on the detection main body and is connected with the second lens group and the focusing group so as to drive the second lens group and / or the focusing group to move in the vertical direction. The lens focal length adjusting range can be increased.

The application discloses a kind of high-speed acquisition system and acquisition method applied to optical absolute gravimeter laser interference fringe signal, the system includes analog signal conditioning unit, analog-digital conversion unit, system core control unit, data cache unit, data transmission unit and measurement and control terminal processing display unit.The application is directed to laser interference fringe signal frequency is high, voltage amplitude is low, acquisition rate is fast, and absolute gravity precision measurement requires signal integrity, measurement precision is high, and the high-speed acquisition system of laser interference fringe signal of optical free-fall absolute gravimeter based on FPGA is designed, the advantage of FPGA parallel computation processing is fully utilized, in combination with serial bus transmission technology (USB) and FIFO cache technology, the processing time of acquisition system in interference fringe signal acquisition, storage and transmission etc. is greatly shortened.The application effectively improves the acquisition speed of absolute gravity, and provides basic guarantee for realizing dynamic measurement and monitoring of absolute gravity.