31results about How to "Reduce laser power density" patented technology

The invention relates to a laser cleaning device and a laser cleaning method. The laser cleaning device comprises a movement platform, a laser, a beam splitter mirror, a reflecting mirror, a vibratingmirror, a drive piece and a protection mechanism. The movement platform is used for placing a workpiece and driving the workpiece to move along a first direction. The laser is used for producing a laser light. The beam splitter mirror and the laser are arranged correspondingly; the beam splitter mirror divides the laser light into a first cleaning laser light and a second cleaning laser light; and the light intensity of the first cleaning laser light is larger than the light intensity of the second cleaning laser light. The reflecting mirror is used for reflecting the second cleaning laser light. The vibrating mirror is arranged on light paths of the first cleaning laser light and the second cleaning laser light; the first cleaning laser light is reflected through the vibrating mirror andthen incident onto the workpiece; and the second cleaning laser light reflected through the reflecting mirror is reflected through the vibrating mirror and then incident onto the workpiece. The drivepiece is connected with the vibrating mirror and is used for driving the vibrating mirror to swing, so that the first cleaning laser light and the second cleaning laser light can scan along a seconddirection in a reciprocating way. The protection mechanism is used for applying a protection gas to the workpiece.

An optical fiber transmission device based on hollow light guiding cone coupling for vacuum-transmitting high-capacity laser is provided. A hollow light guiding cone is connected to the input end of the optical fiber, and small injection light spots are obtained by the hollow light guide cone to implement laser optical fiber coupling transmission. The hollow light guiding cone and the interior of the optical fiber are vacuumed or injected with inert gas to enlarge laser capacity of the optical fiber transmission system and enhance output beam quality. The invented device enlarges the lighted area on the laser input end surface effectively, reduces laser power density of the input end surface, and lowers laser damage probability. Linear and nonlinear wastage is decreased by vacuuming the laser transmission path, and the transmission efficiency of the optical fiber transmission system is increased. The invented device is provided with a simple structure, strong innovation and an evident effect.

The invention discloses a high-energy laser beam expanding and absorbing device which comprises a laser beam expanding cone, an energy absorption cavity, a front panel and a fixing plate, wherein the energy absorption cavity adopts a hollow cylinder; the front panel is arranged at a laser incident end of the energy absorption cavity, and the fixing plate is arranged at the rear end of the energy absorption cavity and used for fixing the laser beam expanding cone; and the laser beam expanding cone comprises a pointed beam expanding cone, at least two spherical beam expanding cones and cylinder transition sections which are arranged in the laser incident direction sequentially, and radii of cylinders of the cylinder transition sections are increased gradually in the laser incident direction. The laser beam expanding cone simultaneously realizes beam expanding of incident laser beams in the length direction and the circumference direction of the absorption cavity, and effectively reduces the power density of laser shot to a heat absorption cylinder by the laser beam expanding cone; and by means of the high-energy laser beam expanding and absorbing device, absorption and conduction of hundred thousand joules to a megajoule of high-power laser energy of continuous waves are realized, the measuring accuracy of an energy meter is improved greatly, and the device has wide applicability.

The invention provides a conical cavity type high-energy laser total-absorption energy meter. The energy meter comprises an absorber, a thermocouple sensor, an absorber support, a barrel-shaped insulator, a data acquiring system and a shell, wherein the absorber is made of a high-purity graphite material and has a cone structure; a conical hollow cavity is formed in the absorber; the absorber support is fixedly connected with the shell in a threaded manner; the middle and the bottom of a cone of the absorber are arranged on the support; the insulator is arranged in the shell; the thermocouple sensor is adhered to counter bores in the surface of the absorber; the distance between the bottom of each counter bore in the absorber and the outer surface of the absorber is 40% of the thickness of the wall of the absorber; the counter bores are equidistantly formed along the cone busbar direction and the direction perpendicular to a busbar; and the distance between two optional counter bores along the cone busbar direction is smaller than the length of the cone busbar of the absorber by 10%. By using the conical cavity type high-energy laser total-absorption energy meter, the high-energy laser energy measuring precision can be obviously improved; and the testing capability of the high-energy laser total-absorption energy meter is improved.

The invention provides a system and a method for inhibiting a stimulated Brillouin scattering effect in a high-power narrow-linewidth optical fiber laser amplifier. According to the system, single-frequency laser output by a single-frequency laser device in a high-power narrow-linewidth optical fiber laser amplifier is subjected to phase modulation, wherein the adopted phase modulation signal is phi f (t), phi f (t) is rem (phi (t) / 2pi), single-frequency laser spectrum broadening is achieved, and the purpose of restraining the stimulated Brillouin scattering effect is achieved. Compared with the existing white noise signal modulation and pseudo-random phase encoding modulation, the method of the invention has the following characteristics that efficient stimulated Brillouin scattering suppression can be achieved, and theoretical basis and technical support are provided for further power improvement of a high-power and narrow-linewidth optical fiber laser system.

The invention concretely relates to an interference structured light lighting microscope system based on radial polarization modulation and an interference structured light lighting microscope method thereof, and solves the problems of complex operation of the polarization control method and low luminous transmittance of the present interference structured light lighting microscopic imaging system. The system comprises a polarization beam splitter, a half-wave plate, a spatial light modulator, a first lens, a spatial filter, a vortex half-wave plate, a dichroic mirror, a microscopic object lens, a tube lens and a digital camera. The half-wave plate and the spatial light modulator are successively arranged on the first emergent light path of the polarization beam splitter. The first lens, the spatial filter, the vortex half-wave plate, the dichroic mirror and the microscopic object lens are successively arranged on a second emergent light path perpendicular to the first emergent light path of the polarization beam splitter. The tube lens and the digital camera are successively arranged on the light path of the dichroic mirror perpendicular to the second emergent light path. The complexity of the system is reduced by the used vortex half-wave plate so that the utilization rate of luminous energy is high, the system is suitable for a low-power laser to act as the light source and integration of the structured light lighting optical microscopic system is facilitated.

The invention disclose a total absorption superlaser energy meter which comprises a reflection cone and an absorption cavity, wherein the generatrix of the reflection cone is arc-shaped, the absorption cavity is formed by sealed connection of a base plate, an inner lateral plate, an absorption cylinder and a cover plate, the whole structure of the absorption cavity is concave, the wall of the absorption cylinder is arranged on the light path of a superlaser beam after the superlaser beam is reflected through the reflection cone, and the absorption cylinder is located behind the reflection cone in the front and back direction. According to the total absorption superlaser energy meter, the incident collimated light beam is reflected onto the wall of the absorption cylinder in an axial and circumferential two-dimensional beam expansion mode, the power density of laser irradiating on the wall of the absorption cylinder is reduced greatly, the light receiving area of the reflection cone is increased at the same time, and the laser irradiation bearing capacity of the reflection cone is improved; furthermore, due to the adoption of the cavity structure, the probability that the reflection cone is polluted by dust is effectively reduced, and meanwhile, the exit escape rate of laser is reduced and measurement accuracy of the energy meter is improved.

The invention discloses a method and device for quickly preparing graphene patterns through double beams. The method comprises the steps that continuous laser beams and short-pulse laser beams are focused to the surface of a nickel substrate at the same time, a beam focusing region on the surface of the nickel substrate is quickly heated to the graphene growth temperature by the short-pulse beams within the laser pulse width time, the gathered continuous laser beams are heated continuously so that the temperature of the region can be stably kept at the graphene growth temperature, and the graphene synthesis is conducted; and the device is provided with a pulse laser unit, a continuous laser unit, a dichroscope, a beam shaping and focusing unit, a vacuum chamber, a gas flow control unit and a three-axis precision translation platform, and quick preparation of any graphene pattern can be achieved. According to the method and device, preparation of the graphene patterns can be completed by using the small laser power density, and the cost of the device is lowered effectively; and due to the fact that the pulse laser heating speed is high, the heat-affected zone is small, the edge quality of the prepared graphene patterns is improved effectively, and the preparation speed of the prepared graphene patterns is increased effectively.

The invention discloses a method for rear wall protection in laser processing of a turbine blade by using water and silicon dioxide, comprising the following steps: grinding the silicon dioxide first; then mixing the silicon dioxide with water to form paste; the paste is injected into a blade runner by virtue of a hole in the top of the turbine blade; punching by adopting pulsed laser; after punching, silicon dioxide particles in the runner are flushed out with flowing water by virtue of the hole in the top of the turbine blade; after the silicon dioxide particles are dried with hot air after being totally flushed out, the laser is scattered, reflected and diffracted by the silicon dioxide particles in front of the rear wall after penetrating through the front wall, and laser spots radiated on the rear wall become large, and the energy is reduced, thus, the power density of the laser radiated on the rear wall becomes small, and accordingly the damage of the laser to the rear wall is weakened or eliminated. The method disclosed by the invention is simple in process and low in cost.

The invention discloses a gray cloth laser singeing system. The gray cloth laser singeing system comprises a laser device, and a laser path of the laser device is provided with a laser beam collimation unit, a half wave plate, a polaroid, a beam splitter and an optical focusing system in sequence; the beam splitter is connected with a photoelectric detector, and the photoelectric detector is connected with a data acquisition card, the data acquisition card is connected with a computer, the computer is connected with the laser device and a translation table, and the translation table is connected with a range detector. The invention further discloses a gray cloth laser singeing method. Firstly, to-be-processed gray cloth is laid on the translation table flat; secondly, the laser device is started to form a laser processing beam; thirdly, the gray cloth is subjected to singeing treatment, wherein the computer adjusts the output power of the laser device as well as the distance between the translation table and the optical focusing system according to the photoelectric detector and monitoring data of the laser device; and finally, the surface of the gray cloth becomes bright and clean, that is, singeing treatment is completed. Through the gray cloth laser singeing system and method, the problem of manually controlling the singeing precision is solved, meanwhile, singeing treatmentis uniform, the structure is simple, the cost is low, and implementing is easy to perform.

A frequency-doubled laser generating device comprises a single-frequency laser, a phase modulator, a laser amplifier, a spatial isolator and a frequency doubling device which are connected in sequence, and further comprises a signal generator which generates radio frequency or pseudo-random signals and is used for driving the phase modulator and modulating single-frequency laser with the output phase amplitude being Npi, after being amplified by the laser amplifier, the single-frequency laser is emitted into the frequency doubling device through the spatial isolator, single-frequency or narrow-linewidth frequency doubling light with the laser phase modulation amplitude of 2Npi is obtained, and N is an odd number. The phase modulator can realize phase modulation in a wider wavelength range, and meanwhile, high-power low-frequency fundamental frequency light obtained by the laser amplifier is subjected to frequency doubling to obtain single-frequency or narrow-linewidth frequency doubling light, so that the structure has the advantages of being simple, flexible in design and the like; a new technical scheme is provided for high-power and high-stability single-frequency or narrow-linewidth laser frequency doubling, and high practical value and application prospects are achieved.

The invention relates to a device for treating brain diseases, in particular to a device for treating brain diseases based on a pulse semiconductor laser external irradiation technology, and solves the problems that irradiation light of an existing device cannot effectively penetrate through skull, irradiation treatment is carried out on deep brain cells of the skull, irradiation treatment can becarried out on the deep brain cells of the skull, and adverse effects cannot be generated due to over-high temperature. The device comprises a helmet, at least one pulse type laser generator, a powersupply and a main control box. The device is characterized in that: the helmet comprises a helmet outer layer, a helmet middle layer and a helmet inner layer; the helmet inner layer is made of a transparent material; and the light-emitting end of the pulse type laser generator is fixed on the inner side of the helmet middle layer. after laser penetrates through the helmet inner layer, the following conditions at met: the peak power density is 1-500 W / cm<2>, the average power density is smaller than 500 mW / cm<2>, the laser spot diameter is not smaller than 3 mm, the laser pulse width ranges from 1 ps to 10 ms, and the wavelength is 600-1400 nm.

The invention discloses an end face protection structure of a high-power laser optical fiber. The end face protection structure comprises the high-power laser optical fiber and a glass block which is fused with one end of the high-power laser optical fiber, wherein one end, which is fused with the high-power laser optical fiber, of the glass block is of a cone structure; the cone end face is of a circular or polygonal structure; and the area of the end face is equal to or greater than the area of the optical fiber. According to the end face protection structure, as one piece of conical glass block is fused with the high-power laser optical fiber, the damage to the optical fiber caused by the over-high laser power density generated on the output face of the laser is prevented ; the taper of the glass block is greater than the divergence angle of a light beam output by the optical fiber, so that all lights output by optical fiber are transmitted inside the glass block; the size of the fine end of the glass block is small, so that the difficulty for fusion of the glass block and the optical fiber is reduced; the size of the end face of a thick end of the glass block is larger, so that an anti-reflection film is conveniently plated, and the unnecessary energy loss is reduced; and the structure is extremely suitable for the output end of the high-power optical fiber laser and is also suitable for a coupling input end or output end of a high-power semiconductor laser coupled with the optical fiber.

The invention discloses a tunable slab laser, and belongs to the technical field of lasers. The tunable slab laser aims at improving the output power of a small tunable slab laser. According to the technical scheme, the tunable slab laser comprises a vacuum cavity. A laser path folding system is transversely arranged in the vacuum cavity and comprises a reflection-type blazed grating, a total-reflection concave mirror, a total-reflection convex mirror and a partial-reflection output mirror. After frequency selecting is carried out on oscillation lasers through the blazed grating, the oscillation lasers sequentially pass through the total-reflection concave mirror and the total-reflection convex mirror and are reflected by the total-reflection concave mirror and the total-reflection convex mirror, and finally the reflected lasers are output through the partial-reflection output mirror. The structure is mainly used for the laser, the quality of output laser beams of the laser can be guaranteed, the power density on the grating face can be reduced, and larger power output can be achieved.

The invention relates to a multi-wavelength large mode volume laser, which uses a broadband laser gain medium and a chromatic dispersion optical element in a resonant cavity; the path separation of different resonant wavelengths on the laser gain medium is realized; the multi-wavelength large mode volume laser common path output is further realized. The multi-wavelength large mode volume laser comprises a pumping source, a resonant cavity full reflection mirror, a resonant cavity output coupling mirror, the laser grain medium and the chromatic dispersion optical element, wherein the chromaticdispersion optical element realizes different paths of different resonant wavelengths on the laser gain medium; the wide-gain laser grain medium realizes multi-wavelength laser gain; the mode competition among different laser wavelengths is avoided; the simultaneous resonance of multi-wavelength laser is realized. The invention provides a novel laser structure; the laser power density of the lasergain medium can be reduced; the heat radiation area is increased; the laser output power is improved; the multi-wavelength laser common path high beam quality output is realized.

The invention discloses a high-energy laser beam expanding and absorbing device which comprises a laser beam expanding cone, an energy absorption cavity, a front panel and a fixing plate, wherein the energy absorption cavity adopts a hollow cylinder; the front panel is arranged at a laser incident end of the energy absorption cavity, and the fixing plate is arranged at the rear end of the energy absorption cavity and used for fixing the laser beam expanding cone; and the laser beam expanding cone comprises a pointed beam expanding cone, at least two spherical beam expanding cones and cylinder transition sections which are arranged in the laser incident direction sequentially, and radii of cylinders of the cylinder transition sections are increased gradually in the laser incident direction. The laser beam expanding cone simultaneously realizes beam expanding of incident laser beams in the length direction and the circumference direction of the absorption cavity, and effectively reduces the power density of laser shot to a heat absorption cylinder by the laser beam expanding cone; and by means of the high-energy laser beam expanding and absorbing device, absorption and conduction of hundred thousand joules to a megajoule of high-power laser energy of continuous waves are realized, the measuring accuracy of an energy meter is improved greatly, and the device has wide applicability.

The invention discloses a laser power meter which mainly comprises an absorber and a shell; wherein the core part is an absorber which is formed by processing a whole block of high-thermal-conductivity material and comprises an absorption target surface, a flow guide assembly, a heat dissipation assembly and the like. The absorption target surface is right opposite to the laser incident port of the shell, and the target surface comprises a series of concentric V-shaped circular ring grooves and is used for improving the absorptivity of incident laser. The flow guide assembly comprises a flow guide column array, and temperature sensors are installed at the two ends of holes between flow guide columns respectively and can measure the temperature of the hot end and the cold end in the absorber, and thereby the power of the laser to be measured can be calculated according to the measured temperature difference. The heat dissipation assembly is arranged in a running water environment so as to improve the heat dissipation efficiency. A water inlet and a water outlet are formed in the shell and connected with external cooling water to achieve water-cooling heat dissipation. The laser power meter adopts an integrated absorber design, so that the heat balance time can be shortened, and the response speed can be improved. Meanwhile, the laser absorptivity of the absorption target surface is high, and the measurement result is more accurate and stable.

The invention provides a crystal growth method and application thereof. The crystal growth method comprises the following steps: S1, uniformly mixing a crystal growth material with an ytterbium ion compound, and pressing the mixture into a tablet; S2, carrying out laser sintering growth on the tablet, so as to obtain microcrystals or nanocrystals; S3, adjusting the size of a laser spot to enable the laser spot to cover the surface of a whole seed crystal, and carrying out in situ annealing to obtain crystals. The crystal growth method can be used for preparing ceramic. According to the research on the crystal growth method which is high in efficiency, high in stability and low in equipment cost, a step-by-step laser sintering method is adopted; the laser power density required in the laser sintering process in the second step is much lower than that required in the laser sintering process in the first step, so that the laser power can be greatly reduced, and crystal growth equipment is very easy to satisfy; furthermore, energy consumption is reduced.

A method for cutting a semiconductor wafer by generating a crack within the wafer, and a system thereof, are provided. The method comprises irradiating a laser beam towards a surface of the wafer and converging the laser beam to form a focal point so that a focal volume defined by the focal point and a boundary of the laser beam within the wafer is formed. Energy encompassed within the focal volume causes the wafer located at the periphery of the focal volume to contract faster than the wafer located within the focal volume, thereby generating a crack within the wafer.

The invention discloses a portable multifunctional laser cigarette lighter and a working method thereof. The portable multifunctional laser cigarette lighter is characterized in that a cigarette lighting tube is arranged on one side inside a shell, and a laser ignition device is arranged on the other side inside the shell; an electric connector is fixed onto the shell and is electrically connected with the laser ignition device; the laser ignition device comprises a semiconductor laser and a laser imaging lens; a light transmission hole is formed in one side, close to the laser ignition device, on the cigarette lighting tube; the semiconductor laser, the laser imaging lens and the light transmission hole are arranged coaxially; a light emitting hole is formed in a position, opposite to the light transmission hole, on the cigarette lighting tube; a hollow opening sphere is detachably connected onto the light emitting hole; and an opening direction of the sphere faces to the light transmission hole. The portable multifunctional laser cigarette lighter provided by the invention does not use organic fuels, has no battery, and is energy-saving, environmental-friendly, and safe and convenient to use. When a cigarette needs to be lighted, the electric connector of the cigarette lighter is plugged into an external power supply interface of a mobile phone or a mobile computer, so that the aim of lighting the cigarette can be achieved. When the cigarette does not need to be lighted, the portable multifunctional laser cigarette lighter can be applied for laser repelling mosquitoes.

The invention discloses a tunable slab laser, and belongs to the technical field of lasers. The tunable slab laser aims at improving the output power of a small tunable slab laser. According to the technical scheme, the tunable slab laser comprises a vacuum cavity. A laser path folding system is transversely arranged in the vacuum cavity and comprises a reflection-type blazed grating, a total-reflection concave mirror, a total-reflection convex mirror and a partial-reflection output mirror. After frequency selecting is carried out on oscillation lasers through the blazed grating, the oscillation lasers sequentially pass through the total-reflection concave mirror and the total-reflection convex mirror and are reflected by the total-reflection concave mirror and the total-reflection convex mirror, and finally the reflected lasers are output through the partial-reflection output mirror. The structure is mainly used for the laser, the quality of output laser beams of the laser can be guaranteed, the power density on the grating face can be reduced, and larger power output can be achieved.

The invention provides rapid detection equipment for an explosive. The equipment comprises a Raman spectrometer, a detection probe is installed on the Raman spectrometer, a fiber product is installedon a surface of a detection end of the detection probe, and light emitted by the detection probe is focused on the fiber product. The detection method comprises the following steps of placing a to-be-detected sample on one side of the fiber product opposite to the detection probe, starting the Raman spectrometer to perform Raman spectrum detection so that original laser can be naturally scatteredwhen the laser emitted by the detection probe passes through the fiber product, and therefore, the laser power density of a local position on a surface of the sample is reduced. According to the invention, the defects of the prior art are overcome, the original laser can be naturally scattered when the laser passes through the fiber product through a large number of tiny hole structures of the fiber product so that the laser power density of the local position on the surface of the sample is reduced, and meanwhile, laser spots cannot be dispersed to be particularly large, and so that Raman signals of the sample are effectively excited under certain laser power density.

The invention disclose a total absorption superlaser energy meter which comprises a reflection cone and an absorption cavity, wherein the generatrix of the reflection cone is arc-shaped, the absorption cavity is formed by sealed connection of a base plate, an inner lateral plate, an absorption cylinder and a cover plate, the whole structure of the absorption cavity is concave, the wall of the absorption cylinder is arranged on the light path of a superlaser beam after the superlaser beam is reflected through the reflection cone, and the absorption cylinder is located behind the reflection cone in the front and back direction. According to the total absorption superlaser energy meter, the incident collimated light beam is reflected onto the wall of the absorption cylinder in an axial and circumferential two-dimensional beam expansion mode, the power density of laser irradiating on the wall of the absorption cylinder is reduced greatly, the light receiving area of the reflection cone is increased at the same time, and the laser irradiation bearing capacity of the reflection cone is improved; furthermore, due to the adoption of the cavity structure, the probability that the reflection cone is polluted by dust is effectively reduced, and meanwhile, the exit escape rate of laser is reduced and measurement accuracy of the energy meter is improved.

The invention provides a crystal growth method and application thereof. The crystal growth method comprises the following steps: S1, uniformly mixing a crystal growth material with an ytterbium ion compound, and pressing the mixture into a tablet; S2, carrying out laser sintering growth on the tablet, so as to obtain microcrystals or nanocrystals; S3, adjusting the size of a laser spot to enable the laser spot to cover the surface of a whole seed crystal, and carrying out in situ annealing to obtain crystals. The crystal growth method can be used for preparing ceramic. According to the research on the crystal growth method which is high in efficiency, high in stability and low in equipment cost, a step-by-step laser sintering method is adopted; the laser power density required in the laser sintering process in the second step is much lower than that required in the laser sintering process in the first step, so that the laser power can be greatly reduced, and crystal growth equipment is very easy to satisfy; furthermore, energy consumption is reduced.

The invention provides a conical cavity type high-energy laser total-absorption energy meter. The energy meter comprises an absorber, a thermocouple sensor, an absorber support, a barrel-shaped insulator, a data acquiring system and a shell, wherein the absorber is made of a high-purity graphite material and has a cone structure; a conical hollow cavity is formed in the absorber; the absorber support is fixedly connected with the shell in a threaded manner; the middle and the bottom of a cone of the absorber are arranged on the support; the insulator is arranged in the shell; the thermocouple sensor is adhered to counter bores in the surface of the absorber; the distance between the bottom of each counter bore in the absorber and the outer surface of the absorber is 40% of the thickness of the wall of the absorber; the counter bores are equidistantly formed along the cone busbar direction and the direction perpendicular to a busbar; and the distance between two optional counter bores along the cone busbar direction is smaller than the length of the cone busbar of the absorber by 10%. By using the conical cavity type high-energy laser total-absorption energy meter, the high-energy laser energy measuring precision can be obviously improved; and the testing capability of the high-energy laser total-absorption energy meter is improved.

The invention provides a medium-thickness plate aluminum alloy double-surface symmetric laser composite wire filling arc welding method. Firstly, the front surface welding is performed through annularlaser wire filling welding; the groove depth is about 2 mm; the groove angle is 30-40 degrees; the welding depth is about 5 mm; meanwhile, the back surface welding is performed through annular laser-arc composite welding; the back surface groove depth is about 3 mm; the groove angle is 45-50 degrees; the welding depth is 6 mm; and finally, the two welding depths are just fused as a seamless complete welding line. The method effectively controls a series of welding defects of easy generation of cracks and air holes and difficult formation in medium-thickness plate aluminum alloys, and meanwhile, solves the problem of insufficient laser power in medium-thickness plate aluminum alloy welding; and in addition, the overburning phenomenon of materials by gauss light spot centers is prevented through annular light spots. The welding method macroscopically improves the welding line formation, and microscopically refines microscopic structures.

The invention provides a high-energy laser semi-integrating-sphere array attenuator, which comprises a front panel arranged along a laser incident direction, a back panel and a plurality of attenuation units, wherein the attenuation units comprise wide-angle sampling taper holes arranged on the front panel, semi-sphere cavities arranged on the back panel, and laser emergent holes which are arranged on the edges of the semi-sphere cavities and are vertical to the back panel; the positions of the wide-angle sampling taper holes are corresponding to the positions of the semi-sphere cavities one to one; and the wide-angle sampling taper holes and the laser emergent holes are respectively arranged on the two sides of the semi-integrating-sphere cavities. In the attenuator provided by the invention, laser is coupled into the semi-sphere cavities via the wide-angle sampling taper holes, is absorbed and diffuse-reflected by the semi-sphere cavities, and then is ejected from the laser emergentholes, large amplitude attenuation of laser power density is realized, and the requirement of attenuation sampling during oblique incidence of the laser can be satisfied.

The invention discloses a method and device for quickly preparing graphene patterns through double beams. The method comprises the steps that continuous laser beams and short-pulse laser beams are focused to the surface of a nickel substrate at the same time, a beam focusing region on the surface of the nickel substrate is quickly heated to the graphene growth temperature by the short-pulse beams within the laser pulse width time, the gathered continuous laser beams are heated continuously so that the temperature of the region can be stably kept at the graphene growth temperature, and the graphene synthesis is conducted; and the device is provided with a pulse laser unit, a continuous laser unit, a dichroscope, a beam shaping and focusing unit, a vacuum chamber, a gas flow control unit and a three-axis precision translation platform, and quick preparation of any graphene pattern can be achieved. According to the method and device, preparation of the graphene patterns can be completed by using the small laser power density, and the cost of the device is lowered effectively; and due to the fact that the pulse laser heating speed is high, the heat-affected zone is small, the edge quality of the prepared graphene patterns is improved effectively, and the preparation speed of the prepared graphene patterns is increased effectively.

A frequency doubling laser generating device, comprising: sequentially connected single-frequency lasers, phase modulators, laser amplifiers, space isolators and frequency doubling devices, and also includes a signal generator, which generates radio frequency or pseudo-random signals for use in Drive the phase modulator to modulate and output a single-frequency laser with a phase amplitude of Nπ. After the single-frequency laser is amplified by the laser amplifier, it is injected into the frequency doubling device through the space isolator to obtain the laser phase Single-frequency or narrow-linewidth frequency-doubled light with a modulation amplitude of 2Nπ, where N is an odd number. Since the phase modulator can achieve phase modulation in a wide wavelength range, and the high-power low-frequency fundamental frequency light obtained through the laser amplifier can be frequency-multiplied to obtain single-frequency or narrow-linewidth frequency-multiplied light, the structure is simple and With advantages such as flexible design, it provides a new technical solution for high-power, high-stability single-frequency or narrow-linewidth laser frequency doubling, and has high practical value and application prospects.