208 results about "Nanosecond laser" patented technology

The present invention belongs to the field of water-jet guided laser micro-hole machining. Specifically, provided is a machining apparatus for a water-jet guided laser micro-hole with a high surface quality, the apparatus comprising: a nanosecond laser device, which is turned on on the basis of a control instruction of a machining control system and refracts an incident laser into a laser water-jet coupling head by means of an optical path transmission unit; a CCD camera, which is arranged above the optical path transmission unit, wherein the laser enters a detection optical path by means of the optical path transmission unit and images on the CCD camera, so as to detect the position of a laser spot diameter at a nozzle of the laser water-jet coupling head in real time, and to complete the coupling of the laser and a water jet; and the laser water-jet coupling head, which is used for coupling the laser, which is focused in the coupling head, and a high-pressure water flow, which enters a coupling cavity through a pipe of a water cavity sidewall, at small holes of the nozzle, so as to perform micro-hole machining on a workpiece. By means of the present invention, interference with a stable jet is reduced, and a micro-hole with a high roundness, a low taper and a good outlet / inlet morphology can be machined, thereby improving the machining efficiency, while also ensuring the precision and quality of micro-hole machining.

The invention belongs to the related technical field of lasers, and provides a high-power subnanosecond-nanosecond laser in order to solve the problems that the range adjustment and the application range of an existing laser are limited, and the structural stability needs to be improved. A modulation semiconductor seed source, an optical fiber pre-amplifier, a light beam isolation system, a high repetition frequency solid pre-amplifier, an acousto-optic modulator frequency reduction module and a multi-stage solid single-pass main amplifier are sequentially arranged along an optical path, continuous adjustable output of repetition frequency and pulse width is achieved, the adjustable range of the repetition frequency is 100 kHz to 1 MHz, the adjustable range of the pulse width is 100 ps to 10 ns, and the adjustable range of the pulse width is 100 ps to 10 ns. The laser power and the light beam quality are remarkably improved, and the method is suitable for the fields of high-precision micromachining, nonlinear optical research, medical cosmetology and the like.

The invention discloses a method for realizing high-quality stripping of large-size diamond by double-laser composite modification, which comprises the following steps: placing and fixing a sample on a three-dimensional mobile platform, and the upper surface of the sample is a crystal face (100); laser generated by an ultrafast laser generator penetrates through the upper surface of a sample and is focused into the sample, and then the laser generated by the ultrafast laser generator is used for performing first spot scanning on the sample to form an independent lattice structure; laser generated by the ultrafast laser generator is adopted to carry out secondary spot scanning on the sample to form a crack interconnected lattice structure; performing third-time line scanning on the sample by using laser generated by a nanosecond laser generator; and ultrasonically stripping the sample in water bath. By adopting a dual-laser composite modification process and combining bionic'honeycomb 'and'turtle shell' crack structure design, the crack is effectively guided to directionally extend along the crystal face (100), the problem of oblique crack when the stripping face is the crystal face (111) in the past is avoided, and the integrity and flatness of the stripping face are greatly improved.

The invention relates to an aluminum alloy strengthening method for high-frequency pulse nanosecond laser surface remelting after low-temperature rolling, which comprises the following steps: firstly, carrying out low-temperature rolling deformation treatment on an aluminum alloy plate to obtain an aluminum alloy material with a high dislocation density fiber structure and realize deformation strengthening; afterwards, the surface of the aluminum alloy plate is subjected to high-frequency pulse nanosecond laser remelting treatment, the aluminum alloy plate is rapidly melted by means of the characteristics of high instantaneous energy density, short acting time and the like of high-frequency pulse nanosecond laser, a small molten pool is obtained, the small molten pool has the great supercooling degree, the driving force of crystallization is increased, and ultra-rapid solidification is achieved; and submicron equiaxed crystals with the grain size ranging from 0.55 micrometer to 0.7 micrometer are obtained on the surface of the aluminum alloy, and fine grain strengthening of the surface is achieved. Through the low-temperature rolling and laser remelting processes, the aluminum alloy material with the special structure is prepared, the interior of the aluminum alloy material is of a hardened state high dislocation density structure, and the surface layer of the aluminum alloy material is of a submicron equiaxed structure.

The invention discloses a multi-physics coupling modeling method based on nanosecond laser etching microgroove resistance reduction simulation, relates to the technical field of laser processing, and is used for solving the problem of optimization of a microgroove resistance reduction effect in a laser etching process. According to the method, the drag reduction effect of the microgroove in the laser etching process is simulated by establishing a coupling model of a plurality of physical fields such as heat transfer, fluid dynamics and material removal. Specifically, an adaptive grid technology is adopted to accurately calculate a temperature field and a flow field in an etching process, and meanwhile, a pulse laser equivalent processing method is introduced to model influences of different scanning times and laser power, so that etching process parameters are optimized. According to the method, the drag reduction effect under different parameters can be efficiently predicted, a theoretical basis is provided for microgroove design and laser etching process optimization, and the method has a wide application prospect.

The invention discloses a high-integration-level interdigital flexible strain sensing array and a preparation method thereof. The preparation method comprises the following steps: circularly cutting a flexible thin film through a nanosecond laser to manufacture a thin film substrate with small holes; after the small holes in the film substrate are aligned with the small points of the interdigital array electrode layer silk-screen printing screen plate, an interdigital array upper electrode layer is manufactured through via hole silk-screen printing; covering the cured upper electrode layer of the interdigital array with a protective film, and performing hot pressing and cooling to form an upper packaging layer; after small holes in the back face of the film substrate where the upper packaging layer is installed are aligned with small points of a back face electrode layer silk-screen printing screen plate, an interdigital array lower electrode layer is manufactured through the silk-screen printing technology; and covering the lower electrode layer of the interdigital array with a protective film, and performing hot-pressing packaging to obtain a complete sensing array. According to the invention, the bottleneck that the traditional interdigital array is complex in design and low in integration level is successfully broken through, high integration of the sensor array is realized, and more complex strain monitoring requirements can be met.

The invention provides a laser marking system and method for metal surface dazzling and coloring, and relates to the technical field of metal surface laser precision machining.The system integrates a femtosecond laser, a nanosecond laser, an optical bread board, a lifting platform, an electric rotating slide, a scanning galvanometer, a focusing lens, a computer control system and an adsorption platform; two laser marking processes of colorful marking and coloring marking are innovatively combined; the femtosecond laser device achieves a colorful effect on the metal surface through ultrashort pulses, and the nanosecond laser device generates a colorful effect of various colors through the heat effect. Automatic switching of the two lasers is controlled through the lifting platform, the computer automatically recognizes the drawing and document process type, and multi-color-zone pattern marking is efficiently completed. The system is simple in structure and convenient to operate, can meet the high-precision double-process marking requirement of the metal surface, and is widely applied to the fields of consumer electronics, anti-counterfeiting technologies and the like.

The invention relates to the technical field of laser processing, and discloses a laser processing method of a ceramic substrate, which adopts an ultrashort pulse laser and nanosecond laser dual-laser system process, integrates the advantages of precise surface modification of ultrashort pulse laser and efficient processing of nanosecond laser, and forms a micron-sized porous sacrificial layer on the surface of a ceramic material. Micropores and microcracks on the micron-sized porous sacrificial layer destroy the continuous heat conduction path of the original compact ceramic, and heat is gathered on the micron-sized porous sacrificial layer formed on the surface, so that when subsequent nanosecond laser acts, compared with the original smooth ceramic substrate, the generated cracks are easy to block, two-dimensional cracks are not easy to generate on the surface of the ceramic substrate, and the surface of the ceramic substrate is not easy to crack. And low-power and high-efficiency processing can be carried out on the ceramic material without coating an auxiliary material, and high-absorption and low-heat-influence processing is realized.

The invention provides a method for improving passivation contact performance of a p region of a TBC battery, which comprises the following steps of: pretreating an n-type monocrystalline silicon wafer, depositing a SiO2 layer and boron (B) doped polycrystalline silicon (poly-Si), etching, performing laser ablation and the like, then depositing phosphorus (P) doped poly-Si, and finally depositing a passivation and anti-reflection layer and preparing a metal electrode. A tunneling oxide layer and boron in-situ doped polycrystalline silicon are deposited in a p region by adopting an ultra-low temperature plasma enhanced chemical deposition (PECVD) mode, the reaction of SiH4 and N2O is introduced to improve the deposition effect of the oxide layer at low temperature, the compactness of a film layer at low temperature is ensured to improve the separation of B on a SiO2 / c-Si interface, and the passivation performance is improved; b doping poly-Si is adopted in the p region, meanwhile, processing is matched with a nanosecond laser, non-equilibrium doping of the B to the poly-Si is achieved, the ultrahigh doping concentration is obtained, the p region passivation performance of the TBC is improved, and then the open-circuit voltage and the conversion efficiency of the TBC battery are finally improved.

The invention provides an infrared femtosecond and infrared nanosecond laser combined machining system and a bionic machining method, and relates to the technical field of laser surface machining. According to the method, rapid rough machining and pre-structure construction are achieved through nanosecond laser, then fine modification and micro-nano structure regulation and control are conducted through femtosecond laser, the machining efficiency and the structure quality can be remarkably improved through the synergistic effect of the nanosecond laser and the femtosecond laser, meanwhile, the heat influence is reduced, high-precision and low-damage machining of the SiC surface is achieved, and the machining quality is improved. And a technical support is provided for constructing a surface structure with special functionality.

The invention discloses a clamping system for nanosecond laser welding of metal foil and film-like plastic, and relates to the field of laser welding. It comprises two supporting bases, on which clamping assemblies are respectively provided, and further comprises a quartz glass pad and a high-transmittance quartz glass sheet. The quartz glass pad, the metal foil, the film-like plastic, and the high-transmittance quartz glass sheet are fixed together by two clamping assemblies. The invention has a simple structure and a reasonable design. By arranging a quartz glass pad and a high-transmittance quartz glass sheet, the invention not only ensures the fixation between the metal foil and the film-like plastic, but also makes the metal foil and the film-like plastic completely spread and in close contact. The clamping force is controlled by the clamping bolts and pressure sensors on both sides, which is convenient for adjusting the welding effect. The integration of the base and the clamping device enables the entire fixture to be stably installed and easy to operate, improves the stability during the welding process, ensures the accuracy of welding, improves the quality of welding, and has good practicality.

The invention provides a method for processing a micropore by combining vortex beam shaping femtosecond laser with nanosecond laser, which comprises the following steps of: firstly, taking charge of melting and sublimation of a material by utilizing the high-power characteristic of the nanosecond laser, and then taking charge of finish machining of the hole wall of the processed micropore by utilizing the characteristics of small heat affected zone and high peak energy of the femtosecond laser. Therefore, the problems that the heat affected zone of the hole wall of the micropore machined by nanosecond laser is large, and the machining quality of the hole wall is poor due to material melting and recasting are solved. Therefore, the advantages of high efficiency of nanosecond laser micropore processing, small thermal damage area of femtosecond laser material processing and high micropore pattern quality of the processed micropore are combined, coarse and fine synchronous processing is finally realized, and the processing quality of the micropore wall is improved.

The invention discloses a high-temperature high-density plasma generation and radiation opacity measurement method, which comprises the following steps: clamping a target material by using low-density low-Z-element foam to form a sandwich structure sample, and synchronously and directly driving the sandwich sample from two sides by using multiple beams of smooth nanosecond laser, the preparation temperature reaches 1,000,000 DEG C, and the electron density reaches 1 * 1023 pieces per cubic centimeter; then generating an X-ray source through the action of one or more nanosecond laser beams and the high-Z material, measuring the absorption spectrum of the X-ray source penetrating through the target plasma, the backlight spectrum of the X-ray source not penetrating through the target plasma and the self-emission spectrum of the target plasma through a spectrograph, and finally realizing the measurement of the radiation opacity of the high-temperature and high-density plasma. The high-temperature and high-density plasma radiation opaqueness measurement device has the beneficial effects that the high-temperature and high-density plasma radiation opaqueness measurement of which the temperature reaches 1,000,000 DEG C and the electron density reaches 1 * 1023 per cubic centimeter is realized on a million-joule nanosecond laser device.

The application discloses a disk medium high-energy ultra-short pulse laser regenerative amplifier based on CPA technology, comprising: a femtosecond laser seed light source for providing femtosecond seed light; a chirped Bragg fiber grating for expanding the femtosecond seed light into nanosecond laser pulses; an optical coupling input and output device for coupling input of the nanosecond laser pulses and coupling output of the nanosecond laser pulses after amplification processing; a regenerative amplification laser cavity for regenerative amplification processing of the coupled-in nanosecond laser pulses; the optical coupling input and output device comprises a fiber coupling collimation module, an optical isolator, a first 1 / 2 wave plate and a thin film polarizer; the regenerative amplification laser cavity comprises a Pockels cell, a second 1 / 2 wave plate, a first reflection module, a second reflection module, a first telescope module, a second telescope module, a first disk gain medium, a second disk gain medium and a third reflection module; the regenerative amplifier can realize high-repetition-frequency and high-pulse-energy laser pulse output.

The invention discloses a nanosecond laser swing welding method for glass and metal, and belongs to the technical field of laser processing. The invention aims to solve the problem that the existing short-pulse laser welding of glass and metal needs a complicated pretreatment process to improve the contact state of glass and metal. The method comprises the steps of 1, cleaning a to-be-welded metal surface; 2, naturally stacking the to-be-welded glass and the cleaned to-be-welded metal; thirdly, the position of a laser focal plane is adjusted, and laser penetrates through the to-be-welded glass to be focused on the to-be-welded area of the to-be-welded metal surface; 4, setting a laser scanning path through computer control software; 5, enabling the laser to swing in an overlapped manner on the basis of a laser scanning path; and 6, naturally cooling and solidifying. The nanosecond laser swing welding device is used for nanosecond laser swing welding of glass and metal.

The invention discloses a multi-modal AI material quantitative and qualitative rapid detection method, which comprises the following steps: acquiring multi-modal data through a double-pulse laser excitation system, carrying out time-space alignment, and cooperatively exciting light and heavy element characteristic plasmas by using femtosecond laser and nanosecond laser; spectral decoupling and dynamic compensation are carried out based on physical rule embedding, spectral signals are separated, and interference is suppressed; a light-heavy element dual-channel deep learning model is constructed, and multi-modal data is fused, so that feature extraction and prediction capabilities are improved; and a double-source mutual verification optimization model is adopted, so that the result reliability is ensured. According to the method, the limitation of single-mode detection is overcome, multi-component high-precision real-time synchronous detection of coal is realized, the adaptability of the model to complex coal quality and environmental change is improved, and an effective and accurate solution is provided for online monitoring of coal quality of a coal-fired power plant.

The application relates to a substrate with micro-nano composite texture and a preparation method and application thereof, and belongs to the technical field of biological medicine. The preparation method comprises the following steps: S1, adopting a nanosecond laser to perform texture treatment on pretreated metal titanium, forming micro texture on the surface of the metal titanium, and obtaining micro texture metal titanium; S2, uniformly stirring ammonium fluoride in ethylene glycol, then uniformly stirring water in the ethylene glycol, and obtaining an electrolyte; S3, connecting the positive pole of a direct current power supply to the micro texture metal titanium as an anode, connecting the negative pole of the direct current power supply to a platinum electrode as a cathode, and performing magnetic field assisted anodic oxidation treatment on the micro texture metal titanium in the electrolyte, so that nano texture is formed on the surface of the micro texture metal titanium; and after cleaning and drying, a substrate with micro-nano composite texture is obtained. The substrate is applied to a drug-loaded coating of a metal implant, can realize micro-nano multi-scale cooperation, integrates the macrostructure advantage of the micron texture and the surface characteristics of the nanotube, and greatly improves the comprehensive performance of the drug-loaded coating.

The utility model relates to the field of stainless steel plate coloring equipment, in particular to a workbench for nanosecond laser coloring equipment, which comprises a frame and a cooling and supporting integrated device installed through the frame, the cooling and supporting integrated device comprises a plurality of branch pipelines, a plurality of supporting pieces are installed on the branch pipelines at intervals, and the supporting pieces are connected with the frame. A discharge port is formed in the part, between every two adjacent supporting pieces, of the branch pipeline, and the discharge ports are formed upwards; one end of each branch pipeline is closed, the other end of each branch pipeline is communicated with the main pipeline, the branch pipelines are connected in parallel, and the main pipeline is connected with a cooling medium source. By means of the working table, cooling treatment can be provided for the stainless steel plate in the treatment process, and meanwhile the interference influence on suction and collection work of dust particles of a dust removal structure above the working table can be avoided.

The application discloses a kind of processing methods for improving the sterilization performance and anti-adhesion performance of medical titanium metal surface, and the specific steps are as follows: 1) pretreatment is carried out on titanium metal sample and cleaned and dried for standby;2) nanosecond laser is used to process the titanium metal sample after pretreatment, to form micron grid structure on its surface;3) configure zinc oxide seed solution, and spin coating solution on the titanium metal sample after laser processing, so that micron grid structure surface is evenly fixed on zinc oxide seed layer;4) using hydrothermal synthesis method, prepare rod-shaped zinc oxide nanostructure on the titanium metal surface with zinc oxide seed layer spin coated;5) configure ethanol solution containing fluorosilane, modify the surface of micro-nano composite structure, and after standing, dry.The titanium metal surface constructed by the application has the dual functions of sterilization and inhibition of bacterial adhesion, the preparation method is simple, and bacterial resistance is not easy to produce, and has potential application prospect.

The invention relates to the technical field of lasers, and discloses a narrow-linewidth subnanosecond laser. The narrow-linewidth subnanosecond laser comprises a pumping source, a resonant cavity and a coupling system, the pumping source, the resonant cavity and the coupling system are arranged along the same optical axis, and the pumping source serves as gain laser. A laser crystal, a polaroid, a quarter-wave plate, an electro-optical modulator and a Bragg grating are sequentially arranged in the resonant cavity along an optical axis. The end face of the Bragg grating away from the coupling system is plated with a beam-splitting film. Laser forms oscillation in the resonant cavity, and the Bragg grating plays a role in screening longitudinal modes, so that narrow linewidth output is realized. The polaroid and the quarter-wave plate are matched to play roles of polarization analysis and light splitting. The voltage on the electro-optical modulator is periodically adjusted to periodically adjust the loss in the resonant cavity so as to output the subnanosecond pulse laser.

The invention relates to a method for displaying latent fingerprints based on nanosecond laser preparation and oxide film transfer. Belongs to the field of latent fingerprint development. The method comprises the following steps that a transparent material is attached to metal, nanosecond laser penetrates through the transparent material and irradiates the surface of the metal through multi-line scanning, the metal is subjected to phase change, generated metal oxide molten particles are attached to the surface of the transparent material, and a compact metal oxide layer is formed. The oxide layer is arranged above the latent fingerprint, and after laser multi-line scanning, the oxide film and the transparent material interface form a high-voltage area. Through heat conduction, the oxide attached to the latent fingerprint is heated to be subjected to phase change, is driven by high pressure to be transferred to the surface of the fingerprint, is in contact with a latent fingerprint sample at a relatively low temperature and then deposits to push the molten mass to the surface of the latent fingerprint, and the molten mass deposits to form a film. But as skin secretions are attached to the ridge line, the deposition capacity of a molten mass is weak, the contrast ratio of the skin secretions and the molten mass is enhanced, and fingerprints appear. The method has the advantages of simplicity in operation, no pollution, low cost and the like. The method has potential application prospects in the criminal investigation field.

The application discloses a kind of for CFRP big depth-diameter ratio array hole multi-pulse width laser composite processing system and method.The system includes: multi-pulse width laser generation module, for outputting two initial laser beams;Beam shaping module, for the optical axis of two initial laser beams is adjusted to coaxial, the initial laser beam is shaped, adjusts the polarization state of initial laser beam, initial laser beam is modulated into two sub laser beams, adjusts the energy distribution of two sub laser beams, two sub laser beams are converted into two mirror image symmetrical distribution in the focusing laser beam array of two sides of the CFRP matrix to be processed.The application can be applicable to the high-efficiency high-precision processing of CFRP big depth-diameter ratio array hole, and nanosecond laser is used to improve processing efficiency, and femtosecond laser is used to effectively inhibit carbon fiber delamination and thermal damage of resin matrix.

The present invention discloses a numerical simulation method for laser-induced phase explosion based on the finite element method, which relates to the technical field of high-power laser and material interaction. Laser parameters are preset to establish a numerical simulation model for nanosecond laser ablation of metals. Laser energy is used as a heat source term to generate a two-dimensional numerical grid for the calculation domain of metal ablation. Phase change heat transfer theory is used to consider the metal's phase change, phase interface movement, and particle evaporation backscattering effects to simulate the physical process and obtain the saturated vapor pressure, hot liquid pressure, and material surface temperature. Based on these saturated vapor pressure, hot liquid pressure, and material surface temperature, the numerical simulation model is discretized and solved using the finite element method. Particle tracking is used to simulate the gas-liquid phase splashing process at the moment of explosion. The present invention can accurately predict the dynamic evolution characteristics of phase explosions during laser ablation, providing important theoretical support and technical assurance for fields such as laser processing, laser propulsion, and laser micro-nano processing.

The invention discloses a system for generating 532nm green light through frequency doubling of 1-micron narrow-linewidth nanosecond laser, which effectively inhibits the nonlinear threshold of an optical fiber amplifier, realizes high-power output of 1-micron narrow-linewidth nanosecond laser while ensuring high light beam quality, and realizes high-efficiency frequency conversion of a pumping nonlinear crystal. The all-fiber polarization-maintaining cascade amplifier comprises a fiber laser seed source system, a fiber pre-amplification device and a fiber main amplifier. The fiber laser seed source system adopts a direct modulation semiconductor laser, the main amplifier adopts a polarization-maintaining conical fiber as a gain medium, the all-fiber polarization-maintaining cascade amplifier outputs narrow linewidth nanosecond laser, and each part adopts an all-fiber welding mode; according to the solid cavity external frequency doubling device, narrow linewidth nanosecond laser is collimated and focused through a lens system, the polarization extinction ratio is improved through combination of a half slide and a polarization slice, meanwhile, the power of injection pump light is adjusted, finally, the laser is coupled into an LBO crystal, and the size of a light spot and the temperature of the crystal are controlled to achieve high-efficiency frequency doubling green light output.

This invention relates to an atomic-level manufacturing method and apparatus for two-dimensional metal oxide nanosheets based on controllable micro-explosion, belonging to the field of functional nanomaterials and atomic-level precision manufacturing technology. This invention uses transition metal energetic complexes and energetic oxygen compounds as metal-oxygen integrated precursors. Under the constraint of an array-type nano-confined microcavity, controllable micro-explosions are synchronously triggered by nanosecond lasers to achieve nanosecond-level stoichiometric precision in the directional self-assembly of two-dimensional metal oxide nanosheets. The preparation cycle of this invention is reduced to less than 10 minutes, and the overall energy consumption is less than 1% of that of the traditional hydrothermal method. The product has excellent specific surface area, photocatalytic and cycling performance, and is 100% compatible with existing mass production lines. It is suitable for large-scale manufacturing in fields such as photocatalysis, energy storage, gas sensors, and environmental governance.

This invention discloses a two-dimensional infrared spectroscopy system and its detection method that combines acid-base step and pulsed heating. The system includes a femtosecond laser, an optical parametric amplifier and difference frequency generator, a frequency divider, an electronic time delay generator, a nanosecond laser, a detachable optical parametric oscillator providing 355nm light pulses, an optical parametric oscillator providing 2020nm light pulses, a monochromator and a mercury cadmium telluride array detector, an integrator and data acquisition card, a computer, a chopper, a time-resolved pulse generation chamber, and a sample chamber. This invention retains the original pulsed heating trigger mode by using a nanosecond light source with a detachable optical parametric oscillator providing 355nm light pulses. It achieves convenient switching between the acid-base step and pulsed heating modes through a dichroic mirror and a reversible reflector. Before and after switching, the propagation direction of the nanosecond pulses is completely consistent, and the relative time delay is corrected by the electronic time delay device.

A nanosecond laser spatio-temporal regulation method based on a double-cone collision direct-drive laser apparatus, and an apparatus. The regulation method comprises: when a near-isentropic compression waveform for driving implosion is satisfied, redistributing temporal waveforms of all sub-beams in an apparatus, involving: using a fraction of laser beams to generate a low-energy foot pulse, which is focused on a relatively large target surface, such that the target surface slowly contracts inwards under the action of the low-energy foot pulse and contracts to a relatively small target surface by the end of the duration of the low-energy foot pulse; and at this time, using the remaining majority of laser beams to generate a main drive pulse, which is focused on the relatively small target surface, thereby realizing zooming.

The present invention discloses a method for actually measuring the attenuation coefficient of broadband laser ultrasonic Lamb waves in metal thin plates, belonging to the field of nondestructive testing. Data acquisition stage: Use a nanosecond laser to set a point source excitation on the surface of an aluminum alloy thin plate, and then use a scanning laser Doppler vibrometer (SLDV) to measure the wave field and collect linear wave field data. Data processing stage: Use the time-frequency analysis of continuous complex wavelet transform to obtain the time-frequency spectrum of the one-dimensional wave field signal. Determine the effective analysis range, including the time upper limit and the frequency upper limit. Extract the amplitude data represented by the intercept line. Attenuation characteristic analysis stage: Extract the peaks of the amplitude data at multiple distance points to obtain discrete points of the amplitude change with distance at a specific frequency. The present invention provides a method for actually measuring the attenuation characteristics of broadband laser ultrasonic Lamb waves. The solution of the attenuation coefficient provides an important theoretical reference for the calculation of the effective detection range and the selection of the filtering frequency of damage scattered waves.

The present invention relates to a laser beam combining and forming device and method with coordinated spatiotemporal phase control, which mainly includes a laser spatiotemporal beam combining device, a laser beam splitting device, and a laser shock forming device. The laser spatiotemporal beam combining device includes two nanosecond lasers, three one-way glasses, three reflectors, a transmission device, and a high-reflective material; the laser beam splitting device includes multiple motors, multiple semi-transparent mirrors, and multiple delay devices; the laser shock forming device includes optical glass, a gasket, an x-y-z three-axis processing platform, and a water spray device. The present invention first uses polarization beam combining to combine two pulse lasers, and then multiplies the combined laser to obtain laser energy with a greater energy density; then, the laser beam splitting device can obtain ultra-high repetition rate laser pulses. The shock waves under the ultra-high repetition rate will have mutual influences, providing a new method for laser shock forming.