32 results about "Nanosecond pulse" patented technology

We present a ground-based laser system for searching, ranging, and tracking that actively illuminates small resident space objects (RSOs) in low Earth orbit (LEO) and observes position and transit-time of reflections, enabling orbital custody of most one-to-few centimeter-sized objects. A diode-pumped alkali laser (DPAL) augmented with mode-locking and Q-switching serves as an illuminator and offers exceptionally high spectral brightness due to its output beam's sub-nanosecond pulse duration and picometer-level spectral linewidth. Kilohertz fast-rastering enables interrogations of distinct few-meter-sized sky-patches at megahertz rates. Paired on the observation side with one or more telescopes outfitted with Faraday anomalous dispersion optical filters (FADOFs), image intensifiers, multi-pixel arrays, and nanosecond timing, the combined system could offer nearly background-free discoveries of RSOs every hour, even during daytime. Periodically re-flashing previously discovered objects to maintain orbit custody expends only a small fraction of total observing time.

Diamond through hole forming method and device based on laser coupling high pressure water jet, including the following steps: the diamond to be processed is fixed on a three-dimensional moving processing table, high energy density of an ultrashort pulse laser is used to realize non-thermal melting processing of the diamond, and an initial blind hole with a graphite residual layer is quickly formed on the diamond; a high pressure water jet mixed with a first oxidizing corrosion component is used to act on the initial blind hole, the graphite residual layer on the initial blind hole is removed, and the blind hole is reamed; a high pressure water jet containing a second oxidizing corrosion component is sprayed, and a nanosecond pulse laser is coupled to act on the reamed blind hole, a processing mode similar to water guide laser is formed, and a set through hole structure is obtained. The three-step method of laser direct drilling pretreatment, high pressure chemical water jet reaming processing and chemical assisted laser reaming polishing is adopted, rapid and high precision processing of the diamond through hole is realized, the processing efficiency, precision and quality are greatly improved, the cost can be reduced, and the method is environmentally friendly and efficient.

This invention provides a full-link detection device and method for laser interferometric velocimetry systems, relating to the field of transient photoelectric testing technology. The detection device includes a pulse injection module, a signal transmission and conversion module, and a signal acquisition and analysis module. The pulse injection module includes a nanosecond pulse laser and a coupler. The coupler is connected in series between the output end of the fiber laser and the first port of the circulator. The nanosecond pulse laser, after being coupled by the coupler, is transmitted along the entire system link and converted into an electrical signal by a photodetector. The data acquisition unit acquires the signal, and the analysis unit analyzes the characteristics of the electrical signal to achieve full-link status detection. This invention can identify and locate fiber optic path breaks, determine the working status of the fiber optic probe, and predict the intensity of the interference signal in the formal experiment. Even after the system is fully solidified before the experiment, it can still monitor the entire link status in real time, effectively improving the operational reliability and efficiency of the laser interferometric velocimetry system.

A laser-plasma synergistic surface treatment method for CFRP / titanium alloy heterojunctions belongs to the field of heteromaterial bonding technology. First, nanosecond pulsed lasers are used to etch the surfaces of CFRP and titanium alloy to be bonded, constructing a micro-nano composite structure. Then, atmospheric pressure cold plasma is used to activate the etched surfaces, grafting polar functional groups. Finally, the two are bonded and cured using an adhesive. This invention achieves a dual enhancement effect of "mechanical interlocking" and "chemical bonding" by organically combining "laser etching to construct micro-nano physical structures" and "plasma activation to introduce chemical functional groups," significantly improving the interfacial bonding strength of CFRP / titanium alloy heterojunctions. Compared with single treatment methods, this invention can increase the joint shear strength by more than 38%, and the failure mode changes from interfacial failure to cohesive failure. It has advantages such as environmentally friendly process, good controllability, and significant effects, and has broad application prospects in aerospace, high-end equipment manufacturing, and other fields.

This invention discloses an apparatus and method for measuring aerodynamic breakup in hypersonic wind tunnels, belonging to the field of hypersonic aerodynamic measurement technology. It solves the problems of blurred observations and two-dimensional limitations in existing traditional hypersonic wind tunnel aerodynamic breakup measurement devices and methods. This invention features a droplet generator in the hypersonic wind tunnel to generate the droplet to be measured, and a schlieren window in the test section of the hypersonic wind tunnel. A sub-nanosecond pulsed laser is used to emit a laser source. The light source is parallelized by a lens, a small plane mirror, a collimating mirror, and a principal plane mirror, then reflected by a schlieren window on one side of the test section, the droplet to be measured, and a schlieren window on the other side of the test section before finally entering a hypersonic camera. The hypersonic camera is connected to an image acquisition and data processing module. This invention effectively improves the dimensionality of hypersonic wind tunnel aerodynamic breakup measurement and can be applied to measuring hypersonic wind tunnel aerodynamic breakup and the protection design of hypersonic vehicles.

The application relates to the field of femtosecond laser pulse compression technology and discloses a femtosecond laser pulse compression method and system, the method of which comprises generating a femtosecond laser pulse to be compressed; interacting the femtosecond laser pulse with plasma to make the femtosecond laser pulse generate linear negative frequency chirp while expanding the spectrum of the femtosecond laser pulse; and performing positive dispersion compensation on the linear negative frequency chirp, so as to obtain a compressed femtosecond laser pulse. The application can solve the problems existing in the prior art, such as the laser pulse energy being limited by the damage threshold, poor spatial uniformity of the compressed light beam, high cost of compression elements, difficulty in realizing nanosecond pulse width and the like.

This invention discloses a high-voltage nanosecond pulse shaping device and method based on magnetic devices. The device includes: a first magnetic transmission line and a second magnetic transmission line, with their input ends connected in parallel and connected to an initial pulse source; the output end of the first magnetic transmission line is connected to a load terminal; the output end of the second magnetic transmission line is short-circuited to ground; the first magnetic transmission line includes a first magnetic ring arranged along the axial direction and an outer magnetic field coil; the second magnetic transmission line includes a second magnetic ring arranged along the axial direction. Based on the current-dependent nonlinear permeability effect of the magnetic ring, this device simultaneously achieves pulse rise time compression, fall time truncation, pulse width shortening, and suppression of pre-pulse and tail oscillations through the rising sharpening effect of the first magnetic transmission line and the falling truncation effect of the second magnetic transmission line. This overcomes the limitation of single nonlinear transmission line or magnetic switching technology, which can only optimize single pulse parameters, and can obtain high-quality pulse waveforms at the load terminal.

A mid-infrared laser generation system based on dispersion-managed soliton bunch pulses. The system can achieve high-power, high-efficiency and high-proportion mid-infrared laser output, and has the advantages of an all-fiber configuration, a compact structure and a high power proportion in a longer-wavelength region of a mid-infrared spectrum. A pulsed fiber laser device generates a nanosecond pulse laser in a 1.5-micron band. A fiber pulse stretcher is made of a single-mode silica fiber, splits nanosecond pulses into a plurality of ultrafast soliton pulses by means of a nonlinear effect, and performs spectral energy conversion from 1.5 microns to 2.4 microns. A fiber laser amplifier further increases the output power of a stretched pulse laser and extends a spectrum to a 2.7-micron band, and also increases pulse energy beyond a 2.3-micron band. A fiber mode field adapter efficiently couples into a nonlinear fiber pulses generated in the fiber laser amplifier. The nonlinear fiber extends a laser to a mid-infrared 3-5-micron band, thereby achieving high-power, high-efficiency and high-proportion mid-infrared laser output.

The application provides a flexible conductive film and a preparation method and application thereof, and the preparation method comprises the following steps: step S1, dispersing nanoparticles in a solvent to prepare a nanometer ink; the nanoparticles are one of Cu, Cu@Ag or Cu@Ni nanoparticles, or a mixture of two or more thereof; step S2, using screen printing or ultrasonic printing to print the nanometer ink on a flexible substrate to obtain a conductive film pattern; step S3, performing heat sintering on the obtained conductive film pattern under a nitrogen atmosphere, the heat sintering is performed at a heating temperature of 200-300 DEG C for 10-30 min; and step S4, placing the conductive film pattern after heat sintering in air, and performing laser sintering treatment by using an ultraviolet nanosecond pulse laser. The technical scheme of the application can effectively improve the comprehensive performance of the conductive film, can realize low-temperature rapid sintering, and is stable in process, and can be compatible with fine forming and large-scale production.

The application relates to the field of femtosecond laser pulse compression technology and discloses a femtosecond laser pulse compression method and system, the method of which comprises generating a femtosecond laser pulse to be compressed; interacting the femtosecond laser pulse with plasma to make the femtosecond laser pulse generate linear negative frequency chirp while expanding the spectrum of the femtosecond laser pulse; and performing positive dispersion compensation on the linear negative frequency chirp, thereby obtaining a compressed femtosecond laser pulse. The application can solve the problems existing in the prior art, such as the laser pulse energy being limited by the damage threshold, the poor spatial uniformity of the compressed light beam, the high cost of compression elements, and the difficulty in realizing nanosecond pulse width.

The application discloses a 459.317nm narrow linewidth all-solid-state laser based on a 1064.4nm pumped PPKTP crystal BWOPO and OPA technology. In view of the strict requirements of a cesium atom (Cs) filter on narrow linewidth and frequency stability, a "BWOPO-pre-frequency doubling-OPA amplification-terminal frequency doubling" composite architecture is innovatively provided. A 1064.4nm nanosecond pulse is used as a source, one road is pumped to the BWOPO, the distributed feedback mechanism is used to generate 1837.268nm narrow linewidth signal light, and 918.634nm seed light is obtained after frequency doubling; the other road is frequency-doubled to 532.2nm to synchronously pump the OPA to amplify the seed, and finally 459.317nm blue light is outputted after frequency doubling. The application realizes high-quality laser output accurately matched with the characteristic spectrum line of the cesium atom filter, and the wavelength is in the optimal waveband of ocean communication, and has important value in the fields of underwater optical communication, ocean detection and high-precision spectroscopy.

A non-destructive method for removing particulate contaminants from the surface of chemically coated fused silica optical elements belongs to the field of precision manufacturing and surface engineering technology. The method includes the following steps: S1: irradiating the surface particles of the chemically coated fused silica optical element with a nanosecond pulse width laser; S2: subjecting the fused silica optical element treated in step S1 to a short-time high-temperature annealing process to passivate point defects on the surface of the fused silica particles; S3: subjecting the chemically coated fused silica optical element to HMDS treatment. This invention employs a nanosecond pulse width laser cleaning combined with short-time thermal annealing to remove some particles and passivate point defects on the surface of the fused silica particles, thereby significantly improving the laser damage threshold of the contaminated fused silica optical element. The method of this invention has important reference value for addressing the cleanliness issues of fused silica optical elements in high-power solid-state laser devices and is beneficial for improving the operating efficiency of high-power solid-state laser devices.

This invention relates to an isotropic three-dimensional super-resolution imaging method using a single objective lens, comprising the following steps: outputting a linearly polarized excitation beam through a picosecond pulsed laser and an outputting a linearly polarized loss beam through a nanosecond pulsed laser; adjusting the polarization direction and power of the excitation and loss beams using a half-wave plate and a polarizing beam splitter; incident the loss beam onto a spatial light modulator; modulating the light field by loading a preset phase diagram to generate three focal points with different topological charges, axial positions, and energy distributions; and modulating the polarization state of the focal points using a high-order vortex phase delay plate to separate the loss beams with different polarization components. This invention achieves an imaging resolution of less than 100 nm in both the lateral and axial directions, with similar lateral and axial resolution performance. In three-dimensional super-resolution imaging, it can accurately reflect the true three-dimensional structure of an object. The imaging resolution is directly proportional to the intensity of the loss beam; the stronger the loss beam intensity, the higher the three-dimensional imaging resolution.

This invention discloses a composite anti-corrosion method for carbon steel based on nanosecond laser remelting using a room-temperature blackening film, belonging to the field of metal surface modification technology. Addressing the problems of loose structure, poor adhesion, and insufficient corrosion resistance caused by the physical deposition of traditional room-temperature blackening films, this invention involves in-situ deposition of a rare-earth modified room-temperature blackening film on the carbon steel substrate surface using an ultrasonic oscillation treatment in a room-temperature blackening solution containing cerium nitrate. The blackened film layer is then obtained by scanning the film layer line by line using a nanosecond pulsed laser beam with a predetermined overlap ratio in a zigzag path. Through the heterogeneous nucleation and surface tension reduction effects of rare-earth elements, combined with the rapid melting and molten pool mixing effect of nanosecond lasers, not only is the uniform densification of the blackened film's microstructure achieved, but the diffusion of iron elements in the substrate is also promoted to form a strong bonding interface. This invention effectively eliminates micropores and microcracks in the film layer, significantly improving the adhesion of the carbon steel surface and its overall corrosion resistance in complex environments.

The present application relates to a kind of hexagonal boron nitride atomic level manufacturing method and device based on controllable micro-explosion, belong to two-dimensional material and atomic level precision manufacturing technical field.The present application uses boron-nitrogen energetic compound as boron-nitrogen-energy integration precursor, under the restraint of array type nanometer limited microcavity, by nanosecond pulse quasi-molecular laser synchronous triggering controllable micro-explosion, combined with boron nitride metasomasis growth template and directional uniform electric field, realize nanosecond boron-nitrogen atom directional self-assembly, prepare high-quality single-layer / few-layer hexagonal boron nitride;And by millisecond laser annealing and high-purity nitrogen gas passivation repair lattice defect.The present application compresses the preparation cycle of single-chip 8 inch wafer hexagonal boron nitride to 10 minutes, and the comprehensive energy consumption is only 1% below traditional CVD process, can accurately control layer number and defect density, 100% compatible with existing semiconductor production line, suitable for the large-scale manufacturing of third-generation semiconductor devices, radio frequency devices, flexible electronics and other fields.

Systems and methods are provided that facilitate laser-based spatially-resolved ablation and ionization of a material, with low sample volume and little or no fragmentation. Sub-nanosecond pulses are directed onto a sample with a delay of less than 1 ns. Within an initial 50 fs after the onset of sample irradiation, one of the pulses generates an initial free electron density, and after the initial 50 fs, the other pulse increases the free electron density such that ablation occurs, resulting in an ablation volume having a sub-diffraction-limited lateral area that is smaller than a diffraction-limited 1 / e2 spot size of at least one of the first laser pulse and the second laser pulse, and a depth of less than 1 micron. The pulse intensities are provided such that ablation occurs without substantial analyte fragmentation, facilitating, for example, analysis and identification via mass spectrometry.

A pulse control method and apparatus, an ablation device and system, and a storage medium. The pulse control method comprises: controlling a pulse generator to output a nanosecond pulse sequence and a millisecond pulse sequence, the amplitude of the nanosecond pulse sequence being greater than a preset first threshold voltage, and the amplitude of the millisecond pulse sequence being less than a preset second threshold voltage. The nanosecond pulse sequence having the amplitude greater than the threshold voltage cooperates with the millisecond pulse sequence having the amplitude less than the threshold voltage, such that the effective ablation range can be enlarged, the ablation is more thorough, the muscle contraction amplitude can be effectively reduced, or the muscle contraction probability is reduced.

This invention provides a laser-modified anti-corrosion method for the surface of a magnesium alloy phosphate film, comprising a nanosecond pulsed fiber laser, a pulsed laser beam, a magnesium alloy, a phosphate film, and a motion control platform. The method involves first preparing a manganese-based phosphate film on the magnesium alloy surface, then placing it on the motion control platform, and irradiating the phosphate film using a pulsed laser beam with specific parameters output from the nanosecond pulsed fiber laser. Finally, an epoxy primer is coated onto the modified surface. Under the ultrafast photothermal effect of the laser energy density, the loose hydrated phosphate undergoes in-situ dehydration and reconstructs into a dense anhydrous oxide layer, eliminating micropores and cracks. This invention significantly improves the hydrophilicity of the film surface, transforming the bonding mechanism between the film and the epoxy primer from a simple physical anchoring to a physicochemical synergistic bonding, greatly enhancing the geometric shielding effect and interface locking effect, achieving a substantial leap in the corrosion resistance of the magnesium alloy and the adhesion of the multilayer coating system.

Massively parallel high throughput single-cell optoperation and their uses thereof are disclosed. The disclosed method teaches the use of parallel single-cell printing technique using SU-8 membrane and nanosecond pulsed laser to espouse on single-cell with micro-dish pattern structure. The platform is able to effectively deliver different (small to large) cargo in a different cell type with high transfection efficiency and high cell viability at parallel single-cell resolution. The proposed Bio-MEMS device has potential applications in personalized and regenerative medicine.

This invention discloses a high-energy nanosecond laser with tunable repetition rate and pulse width, and its operating method, relating to the field of laser technology. It includes a solid-state oscillator, an acousto-optic modulation down-conversion module, an energy attenuation module, and a solid-state amplification module arranged sequentially along the optical path. The solid-state oscillator outputs a laser pulse with tunable nanosecond pulse width. The acousto-optic modulation down-conversion module down-converts the laser pulse. The energy attenuation module attenuates the down-converted laser pulse to the same energy. The solid-state amplification module includes at least one solid-state preamplifier and at least one solid-state main amplifier. The main amplifier includes a polarizer, a plano-concave lens, and a side-pumping module. The laser pulse amplified from the previous stage is collimated and shaped by the polarizer and plano-concave lens before being injected into the side-pumping module for amplification. This achieves rapid, online, and programmable adjustment of the output pulse width, thereby obtaining a high-energy nanosecond laser with stable output energy, controllable parameters, and excellent beam quality.

The application discloses a high-reliability interface construction method for self-healing material additive manufacturing, and belongs to the technical field of metal matrix composite material additive manufacturing. The method comprises the following steps: firstly, memory alloy fibers are processed into a string bead shape through selective local etching to form a periodic "thick section-thin section" alternating structure; secondly, nanosecond pulse laser is used to construct a periodic micron groove on the surface of the fiber; and finally, the multi-scale structured fiber is combined with an aluminum-lithium alloy through laser melting deposition under the protection of argon. The molten aluminum-lithium alloy penetrates into the micron groove and coats the thick section under the capillary action, and after solidification, a "macro mechanical anchoring" and "micro mechanical hooking" double interlocking interface is formed. The method starts from physical structure design, and realizes stable and high-strength interface bonding between the aluminum-lithium alloy and the memory alloy without complex metallurgical regulation.

This invention relates to a method for residual stress reduction in high-frequency alternating current combined with nanosecond pulsed laser cleaning. The method includes the following steps: preparing a workpiece to be cleaned and connecting a high-frequency AC power supply to the workpiece; preheating the workpiece to 150-300°C based on the Joule heating and skin effect of the pulsed current; performing nanosecond laser scanning cleaning on the focal plane of the workpiece based on a predetermined scanning path; increasing the peak current density of the power supply to achieve dislocation slip and residual stress release based on the electroplastic effect, and reducing the surface temperature of the workpiece to below 200°C; and turning off the power supply and air-cooling the workpiece to room temperature. This invention not only effectively removes contaminants from metal surfaces and significantly inhibits secondary oxidation, but also precisely controls the thermal effects generated in the cleaning area. By effectively controlling the distribution of residual stress on the surface through high-frequency alternating current, it effectively improves the fatigue performance of metal materials after laser cleaning, thereby achieving a highly efficient and non-destructive laser cleaning technology.

This invention proposes a nanosecond-level pulse integration measurement device, capable of determining the arrival time of the first pulse, integrating and holding a single optical pulse signal before A / D acquisition, thus reducing the speed requirements of the A / D circuit. It includes a PIN photodiode, a photocurrent integrator, an A / D acquisition circuit, and an FPGA controller; the photocurrent integrator, A / D acquisition circuit, and FPGA controller are connected sequentially; the PIN photodiode generates a photocurrent signal representing optical power when laser signals of different widths and frequencies illuminate it; the photocurrent integrator integrates and holds the photocurrent; the A / D acquisition circuit acquires a voltage signal representing the laser pulse intensity; and the FPGA controller determines the first pulse signal, the pulse arrival time, and controls the charging and discharging of the photocurrent integrator.

The application relates to the technical field of laser precision machining, in particular to a rotary part surface spiral groove machining device and a machining method. The machining device comprises the following: a nanosecond pulse laser 2 capable of generating a high-energy-density pulse laser beam; an optical path transmission assembly arranged at a laser exit end of the nanosecond pulse laser 2 and capable of transmitting, shaping and guiding the laser beam output by the nanosecond pulse laser 2; a galvanometer scanner 8 arranged at a laser exit end of the optical path transmission assembly and capable of high-speed deflection scanning of the incident laser beam; a horizontal rotary workbench located at a laser exit end of the galvanometer scanner 8, adapted with a position encoder and capable of clamping and driving a rotary workpiece 15 to rotate around its own axis and move axially; and a controller 1 in communication connection with the nanosecond pulse laser 2, the galvanometer scanner 8 and the horizontal rotary workbench respectively and capable of establishing rigid mapping of laser pulses and the physical position of the rotary workpiece 15. The machining method is based on the aforementioned machining device.

The application discloses a method and system for cutting semiconductor silicon material by combined pulse laser, and the method comprises the following steps: adopting nanosecond pulse laser to scan and irradiate a preset cutting path of a silicon wafer, and forming a preset notch on the preset cutting path of the silicon wafer; adopting millisecond pulse laser to scan and irradiate along the path of the preset notch, and generating brittle fracture of the silicon material along the preset notch through thermal stress generated by the millisecond pulse laser to complete the cutting. The application solves the problems of low efficiency, large thermal influence area and poor cutting quality of the single pulse laser cutting silicon wafer in the prior art.

This invention belongs to the field of laser processing technology and discloses a control method based on the co-frequency coupling enhancement of electric pulses and nanosecond lasers, including: S1. setting the process parameters of the electric pulse device to 1 / f The current density is J S1. The electrical pulse device is activated and applied to the target workpiece; S2. The electrical pulse device continues to operate. t 1+ n / f Then, the nanosecond laser equipment is activated, and the target workpiece is simultaneously subjected to individual laser shock treatment; S3. Wait t 2+ n / f Then shut down the electrical pulse device; S4. Use the workpiece robot to move the workpiece along the predetermined circular path. r S5. Waiting n / f After the specified time, restart the electrical pulse device and repeat steps S1-S5; S6. Complete all pulse laser counts. m This completes all processing. The present invention achieves uniform strengthening of the material by driving the emission of a nanosecond pulsed laser during the application of a pulsed current, allowing both the electrical pulse and the laser to act simultaneously on the material.

This invention belongs to the field of photoacoustic transduction technology, specifically relating to a transceiver integrated fiber optic photoacoustic transducer and fiber optic hydrophone device. The device includes a fiber optic photoacoustic transducer and a fiber optic hydrophone. The fiber optic photoacoustic transducer comprises a nanosecond pulsed laser, a lens, a fan-in / fan-out module, and a dual-core optical fiber. A trapezoidal slot is formed on one side of the dual-core optical fiber, and an absorption layer is uniformly filled within the slot. Each core of the dual-core optical fiber is an independent single-mode fiber, and one of the single-mode fibers is connected to the nanosecond pulsed laser via the fan-in / fan-out module. The nanosecond pulsed laser has a wavelength of 532 nm, a pulse width of 10-200 ns, a repetition frequency of 1-100 kHz, and a power of 400-800 mW. This invention integrates the transmission and reception of ultrasonic signals onto a single optical fiber, achieving integrated transmission and reception simultaneously. In the optical path, the acoustic signal generated by the transducer does not affect the hydrophone.

A nanosecond pulser system is disclosed. In some embodiments, the nanosecond pulser system may include a high voltage power supply; a nanosecond pulser electrically coupled with the high voltage power supply and switches voltage from the high voltage power supply at high frequencies; a transformer having a primary side and a secondary side, the nanosecond pulser electrically coupled with the primary side of the transformer; and an output electrically coupled with the transformer producing a waveform. In some embodiments, the waveform includes a plurality of high voltage pulses having a pulse amplitude greater than about 2 kV, a pulse width, and a pulse repetition frequency; and a sinusoidal waveform having a waveform frequency and a waveform amplitude greater than 100 V.

The application discloses a nanosecond pulse laser driving control device and method, relates to the technical field of nanosecond pulse lasers, and comprises a main control module connected with a digital-analog conversion module, a direct digital synthesizer module, a reference operation and current monitoring module, a signal output selection module and a signal coupling and current monitoring module respectively; the reference operation and current monitoring module is connected with the digital-analog conversion module; a pulse signal generation and conditioning module is connected with the direct digital synthesizer module and the signal output selection module respectively; the signal coupling and current monitoring module is connected with the signal output selection module; the reference operation and current monitoring module and the signal coupling and current monitoring module are connected with a target nanosecond pulse laser, and the application can improve the stability and reliability in the driving control process of the target nanosecond pulse laser.