238 results about "Short pulse laser" patented technology

The invention discloses an intelligent short-pulse laser processing cutting path optimization method and system. The intelligent short-pulse laser processing cutting path optimization method comprises the steps that S1, coordinate data of all cutting points in a laser processing area are obtained and processed; s2, simulating the heat distribution condition in the laser processing process according to the coordinate data, and outputting a heat distribution diagram; s3, based on the heat distribution diagram, calculating a moving path of the laser head through a path planning algorithm, and optimizing the path to minimize the total moving distance and reduce the influence of a heat accumulation area; s4, the optimized path is adjusted according to specific machining requirements, and parameters are dynamically adjusted through a real-time feedback mechanism; and S5, outputting the optimal cutting path, and applying the optimal cutting path to actual machining equipment to improve the machining efficiency and quality. According to the method, the cutting point coordinate data of the laser processing area are obtained and processed, the heat distribution condition is simulated, path planning is conducted by adopting the ant colony algorithm in combination with the heat distribution diagram, the idle stroke time is minimized, and the influence of a heat gathering area is reduced.

The invention belongs to the technical field of magnetic confinement controllable thermonuclear fusion, and particularly relates to an in-situ laser diagnosis system and method for plasma fuel thermal desorption / impurity deposition in a wall material. The long-pulse laser module emits a long-pulse laser beam, and the long-pulse laser beam sequentially passes through the dichroscope I, the convex lens, the dichroscope II and quartz glass on the vacuum chamber and is irradiated to the surface of the sample to be detected; the short-pulse laser module emits a short-pulse laser beam, and the short-pulse laser beam sequentially passes through the dichroscope I, the convex lens, the dichroscope II and quartz glass on the vacuum chamber of the fusion device and is irradiated to the surface of the sample to be detected; the irradiated radiation light of the to-be-detected sample sequentially passes through the focusing lens, and a spectral signal is transmitted to the spectrum acquisition system. According to the system, high-efficiency in-situ laser thermal desorption can be carried out on fuel gas retained in a wall material, in-situ laser diagnosis of impurity deposition can also be carried out, the two methods are flexibly coupled into one set of system and can be independently used or simultaneously carried out, and a reference basis is provided for fusion reactor divertor operation control and wall material research and development in the future.

The invention discloses a rigid-flex circuit board slotting process based on a laser depth control technology. The rigid-flex circuit board slotting process comprises the steps that the surface of a rigid layer of a rigid-flex circuit board is pretreated, and a laser sensitive layer is sprayed; cNC depth-controlled milling is adopted to form a grooved rough blank structure on the surface of the pretreated rigid layer; positioning laser is used for scanning, a three-dimensional model is established through collected reflected signals, then layered depth-controlled ablation is conducted, second-power laser is sequentially adopted for fine cutting, third-power laser is sequentially adopted for depth calibration, and a groove body structure is formed; cleaning an interface, scanning a groove bottom area and synchronously introducing low-temperature gas; performing morphology repairing treatment, and generating a periodic micro-nano structure on the groove wall by adopting short pulse laser to form a stress concentration resistant surface; depositing an insulating medium layer, and forming a continuous packaging protection layer on the groove wall and the bottom through a vacuum coating process; the high-precision depth-controlled slotting of the rigid-flex circuit board is realized, and meanwhile, the ultra-low thermal damage and anti-fatigue structure and long-acting environmental stability are realized.

The present invention provides a method and apparatus for laser stripping a silicon carbide ingot. The method first transmits an ultrashort pulse laser beam through the first end face of the silicon carbide ingot and focuses it on a set depth layer of the ingot. A cavity-modified region and a crack-modified region are generated above the set depth layer, respectively, and scanned to form the cavity-modified layer and the crack-modified layer. A short pulse laser beam then transmits the second end face of the silicon carbide ingot and focuses it on the cavity-modified region. The beam scatters and propagates within the cavity-modified region, causing the heat from the short pulse laser beam to act on the cavity-modified region, causing cracks within the crack-modified region to grow laterally outward. Scanning is then performed to connect cracks within adjacent cavity-modified regions within the cavity-modified layer through lateral growth. This reduces the amount and length of cracks in the modified layer extending longitudinally along the silicon carbide ingot, increases the number and length of lateral crack growth, reduces cutting loss, and reduces waste.

The invention belongs to the technical field of optics, and particularly relates to a terahertz radiation source system of an air plasma antenna, which comprises a laser, an air plasma generation unit, a terahertz radiation generation unit, a terahertz waveguide and transmission system, a detection analysis unit and a control synchronization system, the laser device is a high-power femtosecond laser device and is used for generating ultra-short pulse laser, the pulses can excite plasma in the air, and the problem that a traditional photoconductive antenna terahertz source is low in terahertz radiation intensity due to limitation of a material damage threshold value is solved; the bandwidth of terahertz radiation can be regulated and controlled by adjusting the distance between the plasma antennas, and the interval time of switching on the plasma antennas can be controlled by controlling the delay time of the third beam of laser, so that the regulation and control of the terahertz wave intensity are realized.

The invention discloses a nickel-based alloy additive manufacturing method for high-frequency ultrasonic dynamic forging printing. The method comprises the steps that nickel-based alloy powder and a base plate are pretreated; scanning the nickel-based alloy powder layer by layer through laser to form a molten pool; in the machining process of each layer, when the temperature of the molten pool ranges from 1000 DEG C to 1400 DEG C, ultrasonic waves are activated to generate compound vibration; the composite vibration comprises axial vibration and transverse vibration; when the ultrasonic vibration phase difference reaches a preset first interval, short pulse laser is triggered; the ultrasonic vibration phase difference is a phase deviation between an ultrasonic vibration waveform and a pulse laser shock triggering moment; and until all layers are machined, a formed part is obtained. According to the scheme, the dislocation density is improved, secondary grain refinement and bubble escape are achieved, and interlayer stress redistribution is made uniform.

The invention belongs to the technical field of photoelectric countermeasure, and particularly relates to a CMOS detector damage system based on time-domain composite pulse laser, which comprises a time-domain composite pulse laser generation module, a light beam transmission and focusing module, a target damage monitoring module, a parameter optimization control module and a detector to be damaged. The time domain composite pulse laser generating module comprises a short pulse laser, a long pulse laser, a pulse synchronous controller, a power adjusting unit, a power supply module and a cooling device, and the power adjusting unit is electrically connected with the short pulse laser and the long pulse laser; and the power supply module is electrically connected with the long pulse laser, the short pulse laser and the cooling device. According to the method, energy loss generated by plasmas in a traditional laser damage method is avoided, the damage efficiency is remarkably improved, efficient transmission and concentration of energy in the multilayer structure are achieved through the synergistic effect of long pulses and short pulses, all layers of materials synchronously lose efficacy in a short time, and the damage consistency of the whole multilayer structure is ensured.

The invention relates to the field of material surface treatment, and discloses a silica gel and metal combined treatment process which comprises the following steps: S1, ultra-short pulse laser is adopted to machine a three-dimensional micro-nano composite structure on the surface of a titanium alloy, the structure comprises a periodic groove array and surface nano holes, and the surface roughness Ra of the titanium alloy is larger than or equal to 5 microns; and S2, a titanium nitride transition layer and a siloxane self-assembly molecular layer are sequentially formed on the roughened titanium alloy surface through atomic layer deposition, and a gradient chemical interface is formed. According to the method, the micro-nano composite structure is processed through ultra-short pulse laser, the interface mechanical embedding area is remarkably increased, the two-dimensional rough limitation of a traditional sand blasting process is broken through, deep barb-shaped anchoring is achieved, the anti-stripping capacity is greatly enhanced, gradient chemical bonding is formed by the atomic layer deposition titanium nitride transition layer and the amino self-assembly molecular layer, and the anti-stripping performance is improved. The thermal expansion difference is effectively buffered, and the interface high-temperature resistance is improved.

The invention relates to a short pulse laser testing device and a testing method thereof.The whole testing device comprises a driving circuit, a first photoelectric receiving assembly, a second photoelectric receiving assembly and an upper computer, a to-be-tested laser chip is driven by the driving circuit to emit light, the upper computer recognizes the type of a parameter needing to be measured, and if the type of the parameter needing to be measured is pulse width, the laser chip needs to be tested; if so, starting a first photoelectric receiving assembly to collect light emitted by the to-be-detected laser chip under the driving of the driving circuit; if the type of the required measurement parameter is power, starting a second photoelectric receiving assembly to collect light emitted by the laser chip to be measured under the driving of the driving circuit; the upper computer tests the to-be-tested laser chip according to photoelectric signals collected by the first photoelectric receiving assembly or the second photoelectric receiving assembly. According to the whole device, different photoelectric receiving assemblies are selected based on different test parameter types to collect photoelectric signals, the test accuracy is ensured, and therefore accurate short pulse laser test can be achieved.

The invention relates to the technical field of lamps, in particular to a plating forming process of a lamp. The problems that the interface bonding force of the coating and the matrix is insufficient and the corrosion resistance of the coating is poor are solved. According to the method, micro-arc oxidation is carried out in the pretreatment stage, a compact Al-Si-O ceramic layer is generated on the surface of a high-aluminum matrix in situ, and in combination with deep diffusion of plasma siliconizing, a transition area with gradient Si distribution is constructed; the pitting corrosion resistance of the coating is optimized through the component gradient design of the inner-layer coating, the middle-layer coating and the outer-layer coating; the surface of the coating lamp is subjected to checkerboard scanning by using short pulse laser, so that the porosity and microdefects of the surface of the coating are improved, and the corrosion resistance of the coating is enhanced; a uniform oxynitride passivation film is generated on the surface of the coating in situ through low-temperature plasma post-oxidation-nitridation treatment, the defect that a film layer is easy to strip in a traditional passivation process is avoided, and the corrosion resistance of the material in long-term service can be stably maintained.

The invention discloses a short pulse laser assisted continuous laser welding device and method. The method comprises the steps that materials are laid; a welding area is divided, and the whole welding area is divided into small areas; performing feature extraction on the small regions; constructing a speed mapping table according to the extracted different features; and planning a laser scanning path according to the speed mapping table. The short-pulse laser-assisted continuous laser welding device and method have the beneficial effects that near-infrared wavelength laser (such as 1064nm) is selected in the whole welding process, and the characteristics of high reflectivity of titanium alloy to the wavelength, high absorptivity of thermoplastic resin, relatively low absorptivity of a resin part in a thermosetting composite material and poor absorptivity of carbon fibers to the wavelength are utilized; laser energy is mainly concentrated on the thermoplastic resin layer, and local heating is achieved. The method comprises the following steps: dividing a region into small regions, extracting features, constructing a speed mapping table, controlling laser energy input, and reducing heat affected zones of the titanium alloy and the thermosetting composite material.

The invention relates to the technical field of anti-counterfeiting mark manufacturing and detection, in particular to a white spirit bottle cap anti-counterfeiting mark manufacturing method based on laser miniature carving and a detection device.The white spirit bottle cap anti-counterfeiting mark manufacturing method comprises the steps that S1, on the basis of the micro-nano optical principle, micro-nano structure parameters containing periodic grooves and protrusions are generated through algorithm optimization; s2, according to the micro-nano structure parameters, an engraving path file matched with ultra-short pulse laser equipment is generated; when the white spirit bottle cap anti-counterfeiting mark is used, through the micro-nano structure design and multi-angle dynamic information display, the anti-counterfeiting mark has extremely high complexity and uniqueness, the counterfeiting difficulty and the counterfeiting cost are greatly increased, the anti-counterfeiting performance of the white spirit bottle cap can be improved, the dynamic change characteristics of the anti-counterfeiting mark are captured through multi-angle imaging, and the anti-counterfeiting mark has good anti-counterfeiting effect. The micro-nano spectrum analysis module detects the authenticity of the micro-nano structure from the microscopic level, and the micro-nano spectrum analysis module and the micro-nano structure complement each other, so that the accuracy and reliability of detection can be remarkably improved, and the possibility of misjudgment and missed judgment can be reduced.

The invention discloses a method and device for optimizing metal powder laying additive manufacturing, the method comprises the steps that optical fiber beam combination is conducted on short pulse optical fiber laser and continuous optical fiber laser which are the same in wavelength to form a composite light source, and the pulse width of the short pulse optical fiber laser is the nanosecond level or the subnanosecond level; the composite light source is output to the galvanometer module through the beam combining optical fiber and then acts on the metal powder bed, and the low-cost and high-efficiency method of full coaxiality and concentricity of lasers of different light sources through the beam combining optical fiber is adopted, so that the printing stability, reliability and large-area uniformity are guaranteed; the short pulse laser and the continuous laser act on an irradiation metal area synchronously and coaxially all the time in the scanning process, metal powder bed melting manufacturing under the force oscillation effect is achieved, and the stability of a keyhole in the additive manufacturing process is improved. According to the method, the pore forming probability of laser powder laying sintering three-dimensional forming can be greatly reduced, the comprehensive mechanical property of a printed piece is improved, and wide popularization and application prospects are achieved.

The invention discloses a femtosecond laser three-dimensional pumping detection imaging method, which belongs to the technical field of ultrafast laser observation, and particularly comprises the following steps of: generating a laser pulse by using an ultrashort pulse laser, splitting the laser pulse by using a beam splitter to generate two beams of pulse light, namely pumping light and detection light, ablating a material by using the pumping light as an excitation source, reflection or transmission imaging is realized at different moments after the probe light passes through the time delay table; a detection angle is freely adjusted in space around a sample to be detected by rotating the light path propagation system, and a detection mode is switched between a reflection mode and a detection mode by rotating the imaging system; a multi-angle two-dimensional transient image is fused into a three-dimensional graph, plasma and a double-temperature model are expanded, the electronic dynamic characteristics of three-dimensional space distribution and the plasma eruption process can be calculated in an ultrafast scale, and three-dimensional information of a femtosecond laser ablation material is reduced. The problem that an existing imaging method cannot achieve three-dimensional imaging of the femtosecond laser processing ultrafast process at any angle in the space is solved.

The invention belongs to the technical field of laser and substance interaction, and relates to a simulation method and system for a temperature field and a stress field of a short-pulse laser irradiation material. The simulation method comprises the following steps: determining simulation parameters including short pulse laser irradiation parameters and material attribute parameters; constructing a thermal-mechanical coupling transient model of the material, and determining boundary conditions of a heat transfer physical field and a solid mechanics physical field of the model; meshing division is carried out on the thermal coupling transient model, and solver parameters are configured; the method specifically comprises the following steps: inputting a short pulse laser pulse width and a short pulse laser frequency into a pre-trained linear neural network model, and calculating to obtain solver parameters; and solving the thermal coupling transient model by applying a solver to obtain temperature field and stress field distribution conditions of the material at different irradiation moments. According to the simulation method, the complex transient physical process of the material under the action of the short pulse laser can be comprehensively and accurately captured.

Disclosed is an optical system for laser machining that enables simpler and more reliable machining of several patterns simultaneously on the same part. The system comprises an ultra-short pulse laser source for generating a source laser beam; a device with a separation means for separating a source laser beam into a plurality of separated laser beams, such that each of the separated laser beams is directed in a direction of propagation specific thereto; a spatial offsetting unit for obtaining, from the plurality of separated laser beams, a plurality of offset laser beams such that each offset laser beam can propagate around a main axis of propagation A specific thereto and is capable of describing a movement around the main axis of propagation A; and a focusing means configured to focus each offset laser beam on a workpiece in the direction of the axis of propagation specific thereto.

The application belongs to the technical field of semiconductor power devices, and particularly discloses a method for laser stripping gallium oxide. The method is characterized in that a super-short pulse laser with a predetermined wavelength is irradiated into the gallium oxide, and a two-photon absorption process occurs when the laser is focused at a position with a specific thickness from the surface. The high temperature generated in the process causes thermal decomposition of the gallium oxide, thereby achieving the purpose of stripping the gallium oxide. Compared with the traditional substrate cutting technology, the stripping method can significantly reduce the cutting consumption of the gallium oxide substrate, and the cut substrate can be reused after polishing, which helps to reduce the manufacturing cost of the gallium oxide device.

The invention relates to a method for manufacturing an elastic sheet microneedle for a crimping test, which is characterized by comprising the following steps: S1, designing a processing pattern according to an outline pattern and a micro bridge contact of the elastic sheet microneedle, the outline pattern comprises a connecting part, a bending elastic part and a test needle body part, the bending elastic part comprises a straight line part and an arc line part, and the test needle body part comprises a connecting part, a bending elastic part and a test needle body part; micro-bridge contacts are formed at two ends of the bent elastic part, and the end parts of the micro-bridge contacts extend into the outline pattern of the elastic sheet micro-needle; s2, a cutting track path of laser cutting equipment is formed according to the machining pattern; s3, the metal sheet with the thickness ranging from 10 micrometers to 500 micrometers is cut through picosecond or femtosecond ultrashort pulse laser according to the cutting track path; s4, redundant metal scraps on the product obtained after laser cutting are removed, and an elastic piece microneedle and a frame are formed; s5, plating a nickel layer and a gold layer on the upper surface of the elastic sheet microneedle in a chemical plating manner; and S6, separating the micro-bridge contacts to obtain a single elastic sheet micro-needle. According to the elastic sheet micro-needle, the micro-bridge connection points extending inwards are arranged at the two ends of the bending elastic part, sheet cutting is carried out in combination with picosecond or femtosecond ultrashort pulses, the produced elastic sheet micro-needle has good consistency, and it is detected that the elastic sheet micro-needle can still keep good consistency after being tested for 300,000 times, and the test requirement is still met.

Systems, methods, and programs for detecting and removing defects on a part during laser powder bed fusion manufacturing are described. A sensor may detect defects on the part during manufacturing of the part. A controller may obtain the sensor data and determine the defect and control a short-pulse laser to remove the defect. Furthermore, processes of manufacture and material properties of the part may be evaluated to determine a likelihood of a defect and the short-pulse laser may be operated to reduce the likelihood of the defect. Furthermore, the short-pulse laser may be operated to reduce stress in layers of the part.

The utility model discloses an intracavity frequency doubling passive mode-locked laser which comprises a pumping source system, a laser crystal, a resonant cavity and a wavelength conversion structure. The pumping source system pumps the laser crystal to generate fundamental frequency laser; the resonant cavity comprises a plurality of resonant cavity mirrors, the plurality of resonant cavity mirrors are sequentially arranged in the optical path transmission direction of the fundamental frequency laser, a saturable absorber is arranged in the resonant cavity, and the saturable absorber is used for realizing passive mode locking of the fundamental frequency laser in the resonant cavity and generating short-pulse fundamental frequency laser; the wavelength conversion structure is arranged in the resonant cavity, the wavelength conversion structure is located between two adjacent resonant cavity mirrors in the multiple resonant cavity mirrors in the light path transmission direction, and the wavelength conversion structure is used for converting the short-pulse fundamental frequency laser into multi-frequency-doubling short-pulse laser with the preset wavelength. According to the scheme provided by the invention, the frequency doubling conversion efficiency of the laser can be improved, so that the laser output efficiency and power of the laser are improved.

The invention provides a controllable processing method for a photoetching single crystal optical fiber multi-ring cladding based on femtosecond laser and a multi-ring mask plate. The technical bottlenecks that in the prior art, the processing efficiency is low, the processing length is limited, and the structural precision is insufficient are effectively solved. The core of the method is that high-energy ultrashort pulse laser generated by a femtosecond laser is combined with a spatial light modulation technology of a programmable multi-ring mask plate to generate multi-layer femtosecond laser spots in specific annular distribution. Micron-scale focusing of multi-ring femtosecond laser beams can be achieved through a precisely-designed optical system, and precise spatial selective refractive index modulation is achieved on the cross section of the single-crystal optical fiber. Compared with a single-crystal optical fiber with a single-multi-ring annular cladding structure, the multi-ring annular cladding structure can further enhance the suppression capability of the multi-ring annular cladding structure on a high-order mode, realizes flexible regulation and control of a light wave transmission mode field, effectively reduces the influence of a multi-mode interference problem in the single-crystal optical fiber on the signal quality, and improves the signal quality. The stability of signal transmission and the quality of sensing signals are improved, and the application requirements of different scenes are met.

Methods and systems for the generation of non-lethal and lethal effects using ultra-short pulse lasers. A laser source generates pulses at the direction of a controller and directs the pulses along an optical path to one or more high-speed beam steering devices, also directed by the controller, which then directs the laser pulses to achieve the desired effects. A computerized controller receives a specification of one or more desired effects for one or more targets and calculates a distribution of ultra-short laser pulses as well as the required characteristics for each of the pulses.

The invention discloses a high-temperature-resistant metal honeycomb equipment forming method which comprises the following steps: S1, performing blanking calculation, extracting a single corrugated plate in a metal honeycomb core body, and unfolding the single corrugated plate according to an equal length principle so as to determine size parameters of a pre-connected area and a to-be-stretched area; s2, chemical oil removal is conducted, specifically, the surface of the metal foil is treated, stains and oxide films on the surface of the metal foil are removed, the subsequent resistance welding strength is improved, and the situation of welding breakage during stretching is avoided; s3, surface activation is conducted, specifically, a mechanical-chemical synergistic process is adopted, silicon carbide abrasive paper is adopted for polishing the metal foil, the surface roughness Ra value of the metal foil is reduced, the specific surface area is increased, the contact angle is reduced, and finally drying treatment is conducted; and S4, material cutting is conducted, specifically, an ultra-short pulse laser cutting technology is adopted for metal foil machining, and the allowance of 10 mm is reserved so that the foil can be fixed. The stretching parameters can be flexibly adjusted according to different curvature requirements, and the preparation problem of the honeycomb core in a complex shape is successfully solved.

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.

A method for measuring the effective spot area of ​​a short pulse Gaussian beam in a vacuum environment comprises a pulse laser, a shutter, an energy regulator, a focusing lens, a sampling mirror, a metal target, a sample stage, an energy meter, a computer, and a vacuum chamber. The method is based on the correlation between the damage profile of the metal target and the energy distribution characteristics of the Gaussian beam. By measuring the change of the corresponding area of ​​the damage profile on the metal target (106) with the irradiated laser energy, the effective spot area of ​​the short pulse laser Gaussian beam at the focus position in the vacuum environment is obtained by fitting. The method is simple and feasible, and can accurately measure the effective spot area of ​​a short pulse laser at different incident angles in a vacuum environment.

The utility model relates to an acousto-optic mode locker capable of improving working frequency and diffraction efficiency, and belongs to the field of photoelectrons. The acousto-optic mode locker comprises an acousto-optic medium which adopts a quartz crystal, the X axis of the quartz crystal serves as an ultrasonic transmission direction, the Y axis serves as a light transmission direction, and the Z axis serves as an optical axis and is perpendicular to the light transmission direction; two parallel polished surfaces are arranged in the X-axis direction of the quartz crystal, one polished surface serves as a sound transmission surface, a welding layer is arranged on the sound transmission surface, a transducer is mounted on the welding layer, and a surface electrode is arranged on the transducer; and the other polished surface is used as an ultrasonic reflecting surface. Fused quartz is replaced by the high-purity quartz crystal, and the tangential direction of the quartz crystal is optimized, so that the influence of the optical rotation of the quartz crystal on the mode-locked laser is reduced to the minimum. The sound wave attenuation coefficient of the quartz crystal is lower, and the acousto-optic merit figure is higher, so that the working frequency and diffraction efficiency of the acousto-optic mode locker can be greatly improved, and the development requirement of an ultra-short pulse laser towards a smaller size is met.

The present invention provides an optical member and a method for manufacturing the same, the method comprising: a removal step for partially removing an antireflection film having a multilayer structure in which a low-refractive-index layer and a high-refractive-index layer are laminated, the antireflection film being formed so as to cover an optical surface of an optical substrate, by irradiation with an ultra-short pulse laser light, and performing non-heat processing on the antireflection film by irradiation with an ultra-short pulse laser light to form an antireflection film having a multilayer structure in which a low-refractive-index layer and a high-refractive-index layer are laminated; the pulse width of the ultra-short pulse laser is 0.1 picosecond or more and less than 100 picoseconds, and in the removal step, the ultra-short pulse laser is irradiated to remove the low refractive index layer, which is the outermost layer of the multilayer structure, or the low refractive index layer, which is the outermost layer, and the conductive layer, which is a layer immediately adjacent to the low refractive index layer. The non-heating processing is a processing for suppressing thermal damage to the high refractive index layer, which is a lower layer of the conductive layer, and the processing for suppressing thermal damage is a processing in which the ratio t1 / t2 of the thickness t1 of a portion removed by the removal step to the thickness t2 of a portion not removed in the high refractive index layer is within the range of 0.90-1.00.

The present invention belongs to an ultrashort pulse laser mode-locked oscillator. In order to solve the problem of how to achieve high-power mode-locked output of the current all-fiber all-polarization-maintaining NPR mode-locked oscillator, there is no report on the research results in this area. The realization of high-power mode-locked output is limited by the technical problems of nonlinear accumulation and pump power. The present invention proposes a high-power polarization-maintaining all-fiber mode-locked oscillator, including a fiber reflector, a polarization beam splitter, a beam combiner, a pump laser, a fiber filter and a Faraday reflector. The output end of the fiber reflector is connected to the incident end of the polarization beam splitter, and the transmission end of the polarization beam splitter is connected to the input end of the beam combiner; the angle between the polarization-maintaining optical axis of the polarization beam splitter and the beam combiner is greater than 0° and less than 45°, the pump end of the beam combiner is connected to the pump laser, the output end is connected to the input end of the fiber filter through the gain fiber, and the output end of the fiber filter is connected to the incident end of the Faraday reflector.

The disclosure relates to an optical system comprising a laser source (1) which generates pulsed laser radiation consisting of a temporal sequence of laser pulses in an input laser beam (EL), a splitting element (2) which follows the laser source (1) in the course of the beam and splits each of the laser pulses into laser pulse replicas separated spatially and / or temporally from one another, a combination element (4) which follows the splitting element (2) in the course of the beam and superimposes the laser pulse replicas in a respective laser pulse in an output laser beam. It is the task of the disclosure to provide an improved optical system compared to the prior art. It should be possible to generate particularly short and thus spectrally broadband laser pulses of high power with the optical system. The disclosure proposes that at least one multipass cell (3) is arranged in the beam path between the splitting element (2) and the combination element (4), through which the laser pulse replicas propagate, wherein the multipass cell (3) contains a medium in which the laser pulse replicas undergo nonlinear spectral broadening.

The invention provides an ultrashort pulse laser ceramic grading method and equipment for realizing the method. The method comprises the following steps: a) adopting an ultrashort pulse laser beam which is generated by a specific SESAM passive mode-locking seed laser and a regenerative amplifier and has the pulse width of 1-15 ps and the monopulse energy of 10 mu J-1 mJ; b) focusing the ultrashort pulse laser beam into a processing light spot with the light spot diameter of 5-50 microns through a light beam shaping transmission module; c) controlling the focused laser beam to perform grain-dividing path processing on the surface of the ceramic workpiece at a scanning speed of 10-1000 mm / s to realize grain-dividing joint cutting with a depth-to-width ratio of more than 10: 1; according to the method, the energy difference between single pulses is smaller than or equal to + / -2%, the difference of peak power between the pulses is smaller than or equal to + / -3%, and the method is stable in working performance, high in consistency, short in action time / low in damage and high in machining precision.