193 results about "Green laser" patented technology

The invention discloses a method for preparing a copper-chromium-niobium alloy high-thermal-conductivity part based on green laser SLM, and relates to the technical field of copper-chromium-niobium alloys. Comprising the following steps that copper-chromium-niobium alloy powder is pretreated; the pretreated copper-chromium-niobium alloy powder is laid on a base plate, green laser is adopted for selective laser melting printing, at least two layers of printing parameters with different energy densities are set in a layered energy gradient control mode, layered printing is carried out, a pore structure with the porosity in continuous gradient distribution is formed, and a pre-machined part is obtained; wherein the wavelength of the green laser is 500 nm to 550 nm, and the spot diameter of the green laser is 15 [mu] m to 30 [mu] m; and the pre-machined part is subjected to heat treatment, and the high-heat-conduction part is obtained. The copper-chromium-niobium alloy part is prepared through the green laser SLM technology, the layered energy density gradient control technology is adopted, and the problems that in copper-based alloy additive manufacturing, the reflectivity is high, the structure is limited, and the performance is insufficient are systematically solved.

The present disclosure provides a semiconductor green laser. The semiconductor green laser, from bottom to top, comprising a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer, and an upper limiting layer. The active layer is a quantum well composed of well layers and barrier layers. Each of the well layers includes any one of AlInGaN, AlInN, AlGaN, AlN, InN, InGaN, and GaN, or any combination thereof. Each of the barrier layers includes any one of AlInGaN, AlInN, AlGaN, AlN, InN, InGaN, and GaN, or any combination thereof. An electron effective mass of each of the well layers is less than an electron effective mass of each of the barrier layers. A spontaneous polarization coefficient of each of the well layers is less than a spontaneous polarization coefficient of each of the barrier layers.

The invention discloses an airborne laser radar sounding data processing method and system, and relates to the technical field of marine surveying and mapping and earth observation, and the method comprises the following steps: collecting original full-waveform data of an airborne laser radar sounding system, the original full-waveform data comprising infrared laser channel data and blue-green laser multichannel data; joint denoising processing is carried out on the original full-waveform data to obtain denoised waveform data, and the joint denoising processing comprises background noise modeling and removing based on machine learning and random noise filtering based on frequency domain low-pass filtering; a collaborative joint denoising strategy is formed by fusing background noise modeling based on machine learning and frequency domain low-pass filtering based on signal-to-noise ratio optimization. According to the method, complex background noise can be accurately estimated and removed, random noise can be adaptively filtered out, weak underwater echo signals are reserved to the maximum extent, and the problem of water depth information loss caused by excessive smoothness is effectively avoided.

The invention discloses a green laser and a laser welding machine. The green laser comprises a pumping source, a first reflector, a laser crystal, a polarization beam splitter, a second reflector, a frequency doubling crystal, a telescope lens group and a spectroscope; the pumping source provides pulse pumping light; the laser crystal absorbs the pulse pump light to generate fundamental frequency laser in an infrared band, the fundamental frequency laser enters the polarization beam splitter and is split into P polarized light and S polarized light, the P polarized light is transmitted out of the resonant cavity, and the S polarized light is transmitted in the resonant cavity; and the telescope lens group converges the fundamental frequency laser to the frequency doubling crystal to generate frequency doubling laser of a green light wave band, and the frequency doubling laser is transmitted by the spectroscope and then is output. The green laser is used for spot welding of high-reflection materials such as copper and aluminum, the maximum single pulse energy can reach 5 J, the maximum peak power is 2 kW, the pulse width ranges from 0.05 ms to 5 ms, the problem of low absorption of the high-reflection materials to laser in the 1-micron wave band is solved, and the green laser is an edge tool for precise spot welding of the high-reflection materials.

The invention relates to a system and a method for detecting thermal stress of an aero-engine blade. The system comprises a green laser, a near-infrared laser, and an optical splitter, a scanning control unit, a signal receiver and a processing module which are connected in sequence, the green laser and the near-infrared laser are respectively connected with the optical splitter; the green laser is used for outputting a first laser beam to the engine blade; the near-infrared laser is used for outputting a second laser beam to the engine blade; the optical splitter is used for combining the first laser beam and the second laser beam to obtain a combined beam; the scanning control unit is used for controlling the combined light beam to scan engine blades; the signal receiver is used for receiving an ultrasonic signal and a photoacoustic signal generated by the engine blade based on the combined light beam; and the processing module is used for processing the ultrasonic signal and the photoacoustic signal to generate a detection result. According to the invention, an accurate and efficient three-dimensional visual solution can be provided for the detection of the thermal stress of the aero-engine blade.

The invention relates to the technical field of laser welding, and provides a high-speed laser welding wire box process based on multi-beam synergy, which comprises the following steps: step 1, at least three laser beams are adopted as a synergy composite heat source, a main laser beam is responsible for penetration fusion welding, and an auxiliary laser beam is responsible for preheating, post-heating or molten pool stabilization; when the copper-aluminum dissimilar material is welded, an auxiliary laser beam is switched into a green laser; and 2, assembling a multi-beam optical regulation and control unit comprising a diffractive optical element, a quartz field lens and a galvanometer scanning module, splitting a main beam into one main beam and two auxiliary beams through the diffractive optical element, controlling focal depth fluctuation by the quartz field lens, and realizing accurate movement positioning of a laser beam by the galvanometer scanning module. Through integration of multi-beam collaborative design and an intelligent control unit, remarkable breakthroughs are achieved in the aspects of welding efficiency, quality consistency and process adaptability, firstly, in the aspect of efficiency and process, the welding speed is greatly increased, multi-station synchronous operation of an automatic welding unit is matched, and the welding period of a single-line box is remarkably shortened.

An apparatus and methods are provided for a handgun stabilizer that enables a shooter to very accurately fire a handgun while remaining well protected by a ballistic shield and looking through a bullet resistant viewing window comprising the ballistic shield. A high visibility green laser sight / high output white light illumination system may be mounted onto the handgun for aiming and illumination, with the handgun being precisely and removably mounted to the side of the handgun stabilizer at a location where the handgun's grip can be ergonomically grasped in the shooter's dominant hand, both for operating the handgun and for controlling the position and orientation of the ballistic shield for aiming purposes. An interface that enables the handgun to be precisely and removably mounted to the handgun stabilizer may comprise a quick-draw holster that is mounted directly onto the handgun stabilizer.

The invention relates to a multi-beam fusion deposition system and method, in particular to a multi-beam fusion deposition system, an additive manufacturing method, a metal welding method and a metal cutting method. According to the multi-beam fusion deposition system, in the deposition machining process of additive manufacturing, metal welding, metal cutting and the like, the blue or green laser, the infrared laser and the pulse laser are matched with one another to act on the to-be-machined material in the deposition area in a synergistic mode, so that the laser absorption rate of the to-be-machined material is increased, and the deposition efficiency is improved. Energy waste in the deposition machining process is reduced, the machining efficiency is improved, the machining cost is reduced, meanwhile, the pulse laser beams can stir the preset molten pool formed in the to-be-machined material, convection is formed in the preset molten pool, energy distribution in the preset molten pool is promoted to dynamically change, components are evenly mixed, and the machining efficiency is improved. And meanwhile, bubbles can overflow from the preset molten pool, the deposition machining quality is effectively improved, and the machining defect rate is reduced.

The invention discloses a copper-chromium contact with high fusion welding resistance and a preparation method thereof, and belongs to the technical field of contact materials. The preparation method comprises the steps that high-purity electrolytic chromium powder and electrolytic copper powder serve as raw materials, after acoustic resonance powder mixing is conducted, powder upsetting and cold isostatic pressing are conducted in sequence, and a green body is obtained; carrying out gradient sintering and finish machining treatment on the green body to obtain a copper-chromium electrode bar; the copper-chromium electrode bar is subjected to atomization powder making, and copper-chromium alloy powder is obtained; after the copper-chromium alloy powder is sequentially subjected to sheathing, heat treatment, seal welding and hot isostatic pressing sintering, a sheath is removed, and a prefabricated body is obtained; and after the prefabricated body is processed, the surface is remelted by green laser, and the copper-chromium contact with high welding resistance is prepared. According to the method, by improving the purity of the copper-chromium contact and optimizing the morphology and distribution of the chromium particles, the prepared contact is high in purity, the chromium particles are fine and uniform in distribution, the welding resistance and the breaking performance are excellent, and the method is suitable for a high-voltage-grade arc extinguish chamber.

The invention discloses an extremely shallow water blue-green laser sounding dynamic refraction vision correction method, which belongs to the technical field of marine surveying and mapping and underwater detection, is used for laser refraction correction, and comprises the following steps: synchronously acquiring binocular images and inertial measurement unit attitude data, and generating a three-dimensional point cloud; according to a light spot area in the laser emission angle index point cloud, fitting a micro-tangent plane to obtain a water surface original normal vector; calculating a confidence coefficient weight according to the image texture definition, and iteratively calculating an optimal estimation normal vector based on the original normal vector and the weight; calculating a real incident angle according to the optimal estimation normal vector and the laser emitting direction; calculating the direction vector of the underwater refracted light according to the Snell's law; and calculating the underwater three-dimensional coordinates of the target point by combining the propagation distance of the laser in the air and the water and the emission origin coordinates. According to the method, the visual confidence is introduced, so that the problem of data failure when the traditional visual sounding encounters water surface reflection, glare or broken waves is solved, and the robustness under the complex sea condition is remarkably improved.

The invention belongs to the technical field of metal-based composite material additive manufacturing, and particularly relates to ultrasonic-assisted green laser equipment for copper-based diamond cooling fin machining, which comprises a rack, a printing cabin, a green laser machining system, an ultrasonic-assisted system, a powder spreading system, a gas control system, an intelligent control system and an online monitoring system. By integrating a green laser processing system and an ultrasonic auxiliary system, an ultrasonic-green laser-powder multi-energy field coupling processing system is constructed, the wavelength of green laser is 532 nm, the absorption rate of copper is increased, and compared with traditional infrared laser, low-power and high-efficiency melting of copper can be achieved, the diamond graphitization risk is reduced from the angle of a heat source, and the production cost is reduced. Ultrasonic vibration is transmitted to a molten pool through a substrate coupling type structure, by means of the cavitation effect and the acoustic streaming effect, the interface wettability of copper and diamond is effectively improved, the interface bonding force is enhanced, the interface thermal resistance is reduced, meanwhile, grains are refined, pores are eliminated, residual stress is reduced, and the comprehensive performance of the cooling fin is remarkably improved.

Embodiments of the present description provide a semiconductor green laser. The semiconductor green laser successively comprises, from bottom to top, a substrate (100), a lower confinement layer (101), a lower waveguide layer (102), an active layer (103), an upper waveguide layer (104), and an upper confinement layer (105). The active layer (103) is a quantum well consisting of a well layer and a barrier layer, the period of the quantum well is z, and z is greater than or equal to 1 and less than or equal to 3; the well layer comprises any one or any combination of aluminum indium gallium nitride (AlInGaN), aluminum indium nitrogen (AlInN), aluminum gallium nitride (AlGaN), aluminum nitride (AlN), indium nitride (InN), indium gallium nitrogen (InGaN), and gallium nitride (GaN), the thickness of the well layer is p, and p is greater than or equal to 5 angstroms and less than or equal to 100 angstroms; the barrier layer comprises any one or any combination of AlInGaN, AlInN, AlGaN, AlN, InN, InGaN, and GaN, the thickness of the barrier layer is q, and q is greater than or equal to 10 angstroms and less than or equal to 200 angstroms; and the electron effective mass of the well layer is smaller than that of the barrier layer, the spontaneous polarization coefficient of the well layer is smaller than that of the barrier layer, and the band gap of the well layer is smaller than that of the barrier layer.

The invention belongs to the field of high-thermal-conductivity composite materials, and particularly relates to a 3D printing copper-diamond composite high-thermal-conductivity material and a preparation method thereof.The 3D printing copper-diamond composite high-thermal-conductivity material comprises a copper matrix and diamond particles dispersed in the copper matrix, and the surfaces of the diamond particles are provided with metal coatings; the copper matrix is formed by copper powder with the particle size of 10-100 microns, and the volume fraction of the diamond particles in the composite material is 40%-50%; according to the method, the titanium plating layer is prepared on the surface of the diamond, the stable titanium carbide transition layer is formed through the reaction of titanium and carbon, the interface thermal resistance between the diamond and copper is remarkably reduced, the interface bonding strength is improved, and heat conduction is facilitated. The selected area green laser 3D printing technology is adopted, a green laser device shows remarkable advantages in the field of 3D printing of copper alloy, and the heat conductivity of the prepared composite material can reach and is remarkably higher than that of pure copper by optimizing the diamond volume fraction and 3D printing process parameters.

The invention belongs to the technical field of additive manufacturing, and particularly relates to a diamond / copper radiator manufacturing method based on 3D printing, and the diamond / copper radiator manufacturing method comprises the steps that diamond / copper composite powder is prepared, and the composite powder comprises diamond particles with nano alloying elements attached to the surfaces and spherical copper powder; and under shielding gas, green laser with the wavelength of 532 nm is adopted for conducting selective laser melting scanning on the composite powder, meanwhile, high-frequency ultrasonic vibration is applied to a molten pool in a laser acting area, and a diamond / copper composite material radiator green body is formed through layer-by-layer powder laying, scanning melting, ultrasonic assistance and layer-by-layer accumulation. Copper matrix crystal grains are refined through ultrasonic energy, residual stress in the printing process is reduced, generation of microcracks is effectively restrained, the mechanical property and reliability of a workpiece are improved, the high absorptivity of green laser to copper and the technical advantages of 3D printing are combined, and high-quality 3D printing is achieved. And the radiator with fine structures such as complex three-dimensional micro-channels and ultrathin fins can be integrally manufactured.

The invention discloses an all-solid-state high-power continuous wave single-frequency ultraviolet laser, and relates to the technical field of photoelectrons and lasers, and the all-solid-state high-power continuous wave single-frequency ultraviolet laser comprises a green laser, a light collimation polarization focusing structure, a frequency doubling resonant cavity, a resonant cavity locking structure and a BBO crystal. The frequency doubling resonant cavity comprises an incident mirror, a first reflecting mirror, piezoelectric ceramics, a second reflecting mirror and an emergent mirror along the laser transmission direction; the first reflecting mirror is fixed on the piezoelectric ceramic; the piezoelectric ceramic is electrically connected with the resonant cavity locking structure; based on a voltage output signal of the resonant cavity locking structure, the expansion and contraction amount of the piezoelectric ceramic is adjusted so as to change the cavity length of the frequency-doubled resonant cavity; and the BBO crystal is arranged at the beam waist between the second reflecting mirror and the emergent mirror. The laser conversion efficiency can be improved while the laser output stability characteristic is improved, and the light beam quality is ensured.

The invention discloses a self-adaptive water depth dual-channel conversion single-photon water depth laser radar and a working method thereof, and relates to the field of single-photon laser radars, in the laser radar, a blue-green laser emits laser to a laser scanning system through a perforated reflector; after a scanning light path of the laser scanning system is reflected by the water surface, an echo signal is returned to the receiving optical system; the receiving optical system divides the echo signal into a linear receiving channel and a single photon receiving channel according to a light splitting ratio, and respectively focuses the echo signal to a linear PMT module and a photon counting PMT module; the main control unit is connected with the data processing and storage module and used for receiving the water depth calculation result output by the data processing and storage module in real time and controlling a switch of the electric diaphragm. According to the invention, a water depth adaptive dual-mode measurement technology is realized, and the efficiency and accuracy of measurement work are improved.

The invention provides a preparation method of a gallium nitride-based laser, which can be applied to the technical field of gallium nitride semiconductor lasers. The method comprises the following steps: providing a gallium nitride substrate; sequentially growing a gallium nitride buffer layer, a lower limiting layer, a lower waveguide layer, an active region, an upper waveguide layer, an electron blocking layer, a novel upper limiting layer, a novel p-type gallium nitride layer and an ohmic contact layer on the gallium nitride substrate to obtain an epitaxial structure; the growth method of the novel upper limiting layer and the novel p-type gallium nitride layer is a step-by-step doping method; and the structures of the novel upper limiting layer and the novel p-type gallium nitride layer are superlattice structures. The doping efficiency and ionization efficiency of Mg impurities at a low growth temperature are improved through a step-by-step doping method and a superlattice polarization induced doping method, and large Mg doping concentration and high hole concentration can be realized at a relatively low growth temperature, so that preparation of low-temperature p-type AlGaN and GaN layers is realized, and the photoelectric property of the gallium nitride-based blue-green laser is improved.

The utility model relates to a laser beam combining device and a projector, the laser beam combining device comprises a first laser assembly, a second laser assembly and a beam combining structure, and the first laser assembly comprises a first green laser and a first blue laser; the second laser assembly comprises a second green laser and a second blue laser; the beam combining structure is used for combining light output by the first laser assembly and light output by the second laser assembly, the beam combining structure comprises a partition diaphragm, the partition diaphragm comprises a first area and a second area which are connected, and blue light output by the first blue light laser device and green light output by the second green light laser device are combined through the first area and then output through the second area; and green light output by the first green light laser and blue light output by the second blue light laser are combined through the second area. According to the invention, by arranging the partition diaphragm, the blue light and the green light of the first laser assembly and the second laser assembly are combined on the same partition diaphragm, so that the optical expansion amount of the combined light is greatly reduced.

The invention relates to a semiconductor external cavity frequency doubling green laser and a preparation method, and belongs to the technical field of semiconductor lasers. On the basis of a conventional 1064nm semiconductor laser, laser is directly irradiated on a frequency doubling crystal, and meanwhile, a resonant cavity is formed by coating a cavity surface of the semiconductor laser and an output end of the frequency doubling crystal, so that a structure of a gain medium in a laser for obtaining green light in an original pumping mode is canceled, the complexity and the cost of the laser are greatly reduced, and the laser is more compact and more compact. And the batch condition is realized. And meanwhile, by adjusting the wavelength of the semiconductor laser and matching with the frequency doubling crystal, laser output with the wavelength of 510-540 nm can be realized, and the cost of the laser with the green light wave band can be effectively reduced.

A half-wave plate and a focusing lens are sequentially arranged on an output light path of a pulse width adjustable infrared laser, the focusing lens is connected with a frequency doubling crystal, the frequency doubling crystal is connected with a frequency tripling crystal, the output end face of the frequency tripling crystal is cut into a Brewster angle, and the output end face of the frequency tripling crystal is connected with a pulse width adjustable infrared laser. The output infrared laser is shielded by the infrared light blocking block after being transmitted in the space, the output green laser is shielded by the green light blocking block after being transmitted in the space, the frequency tripling crystal is connected with the imaging lens, the imaging lens is connected with the input surface of the wedge-shaped lens, and the input surface of the wedge-shaped lens is cut into a Brewster angle. Through fine adjustment of the distance between the imaging lens and the frequency tripling crystal and the distance between the wedge-shaped lens and the imaging lens, the ultraviolet laser output by the wedge-shaped lens becomes circular and is output. The Brewster angle output surface of the frequency tripling crystal reduces the ultraviolet damage probability and separates infrared light, green light and ultraviolet light. The position of the imaging lens is finely adjusted to compensate a light spot ellipse caused by a walk-off effect during frequency doubling.

The invention discloses a tunable white laser system, which belongs to the technical field of laser, and comprises a light source emitting device, the light source emitting device is coupled with a laser beam combining device, the light source emitting device comprises a first light source, a second light source and a third light source, the first light source is a cyan laser source or a green laser source, and the second light source is a third light source. The second light source is a red light laser source, the third light source is a cyan light laser source or a green light laser source, the third light source and the first light source are different in color, and the laser beam combining device comprises a beam splitter assembly and an optical fiber beam combining assembly. According to the tunable white light laser system, the light source with the wave band above blue light is adopted to generate white light laser, complex devices such as a super-continuum spectrum generation device and a white light extraction device are not needed, the system has the advantages of being adjustable in real-time chromaticity and easy to integrate, blue light pollution to the external environment in the white light generation process is avoided, and the system is suitable for large-scale popularization and application. The method has stronger condition adaptability and practicability, and the stability of mixed light is good.

The invention relates to the technical field of laser processing, and discloses a metal polymer composite material cutting process which comprises the following steps: placing a to-be-cut piece on a cutting platform; the to-be-cut piece comprises a metal layer and a polymer layer which are stacked; adjusting parameters of an output laser beam of the laser; the output wavelength lambda of the laser is controlled, so that the laser generates green laser, and the polymer layer is subjected to cold cutting; the value of the output power P and the value of the output pulse frequency f of the laser are controlled, so that the green laser is emitted in a pulse mode, and laser energy is concentrated and acts on the metal layer at intervals; according to the cutting process of the metal polymer composite material, the two-photon energy of the green laser is sufficient to reach the fracture energy of molecular bonds of the polymer layer, the polymer layer can be directly cut without reaching the melting point of the polymer layer, the energy of the pulse laser is concentrated and spaced, and the heat influence caused by cutting the metal layer is discontinuously generated; therefore, the influence on the interface of the metal layer and the polymer layer is reduced, and the cutting quality is improved.

An all-epitaxial, electrically injected surface-emitting green laser operates in a range of about 520-560 nanometers (nm). At 523 nm, for example, the device exhibits a threshold current density of approximately 0.4 kilo-amperes per square centimeter (kA / cm2), which is over one order of magnitude lower than that of previously reported blue laser diodes.

The present application provides an annular spot laser processing system, including a first laser light source, a first half-wave plate, a first dichroic mirror, a second laser light source, a second half-wave plate, a first reflector, a first laser crystal, a second laser crystal, a second dichroic mirror, a first lens, a second lens, a third dichroic mirror, a third lens, a fourth lens, a fourth dichroic mirror, a fifth dichroic mirror, a galvanometer mechanism, a target workpiece, and a platform. By generating a first laser beam and a second laser beam with mutually perpendicular polarization directions through the first laser light source and the second laser light source, and combining and frequency doubling the first laser beam and the second laser beam, a high-power green laser with a wavelength of 500 - 550 nm can be obtained, and a composite laser with a high-power green laser with a wavelength of 500 - 550 nm as the main laser can be generated without using a complex system structure. The entire laser processing process has high efficiency, extremely small spatter, little thermal influence on non-target processing areas, and relatively low production and manufacturing costs.

The application discloses a method for correcting the vision of laser refraction in extremely shallow water, and belongs to the technical field of marine surveying and mapping and underwater detection, and is used for laser refraction correction. The method comprises the following steps: synchronously collecting binocular images and inertial measurement unit attitude data, and generating three-dimensional point clouds; indexing a light spot area in the point clouds according to a laser emission angle, fitting a micro tangent plane, and obtaining an original normal vector of the water surface; calculating a confidence weight according to the image texture definition, and iteratively calculating an optimal estimated normal vector based on the original normal vector and the weight; calculating a real incident angle according to the optimal estimated normal vector and a laser emission direction; calculating a direction vector of underwater refracted light according to Snell's law; and combining the propagation distances of the laser in the air and in the water and the emission origin coordinates, and calculating three-dimensional coordinates of a target point on the water bottom. The application introduces visual confidence, solves the problem of data failure of traditional visual depth measurement when encountering water surface reflection, glare or broken waves, and significantly improves the robustness under complex sea conditions.

A novel environment-friendly building facade construction method comprises the steps that a modular prefabricated outer vertical panel is provided, the prefabricated outer vertical panel is made of a recyclable composite material, the composite material comprises, by weight, 60%-70% of regenerated cellulose, 20%-30% of environment-friendly resin and 5%-10% of a nano reinforcing agent, and a porous micro-nano structure is preset on the surface of the prefabricated outer vertical panel; the surface self-cleaning performance is enhanced; a light alloy frame is installed on the base face of the building outer wall, the light alloy frame is made of magnesium-aluminum alloy materials and fixed to the base face of the building outer wall through embedded expansion bolts, and the surface of the frame is coated with an environment-friendly anti-corrosion coating. According to the intelligent mechanical arm system, the multi-axis mechanical arm, the laser positioning module and the pressure sensor are integrated, the laser positioning module calibrates the installation position of a panel in real time through 532-nanometer green laser, it is guaranteed that the installation error is smaller than 0.5 mm in combination with precise control over 50-200-Newton contact force through the pressure sensor, and the construction precision is improved.

The application provides a high-power optical fiber green laser, and belongs to the technical field of optical fiber lasers; specifically comprises a seed source module, which is used for providing a seed light source with adjustable pulse width and frequency, and performing phase modulation on the seed light source to broaden the spectrum; a first amplification unit is connected with an output end optical path of the seed source module and is used for performing power amplification on the seed light; a second amplification unit is connected with an output end optical path of the first amplification unit and is used for performing power amplification on the signal light again; a third amplification unit is connected with an output end optical path of the second amplification unit and is used for performing third power amplification on the laser; a frequency doubling output unit is connected with an output end optical path of the third amplification unit and is used for performing frequency doubling on the laser amplified for the third time, so as to output green laser with a specified divergence angle and spot size. The application improves the SBS threshold from two aspects of phase modulation and shortening the length of the optical fiber, so that the peak power of the optical fiber green laser is higher.

The invention provides a dual-wavelength beam laser composite additive manufacturing device which comprises a powder feeding nozzle, a red light laser, a green light laser and a scanning galvanometer. A red laser beam emitted by the red laser is output by the laser output channel and is focused on the processing surface to form a red light spot; a green laser beam emitted by the green laser is controlled by the scanning galvanometer to enter the red laser beam in a circular swinging mode and is focused on the machining face to form a green light spot, and the formed green light spot is located on the inner side of the red light spot. The invention provides a dual-wavelength beam laser composite additive manufacturing method. A scanning galvanometer is adopted to control a green laser beam to periodically swing in a red light spot coverage area according to a set circular path. According to the method, the dynamics and microstructure of the molten pool are optimized, the thermal gradient and the cooling rate are adjusted, and ideal conditions are provided for high-density manufacturing of materials such as nickel-based high-temperature alloy, aluminum alloy and copper alloy.

The present invention discloses a semiconductor laser comprising: a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, and an upper confinement layer, arranged in order from bottom to top; the active layer comprising a well layer and a barrier layer; the electron effective mass of the well layer of the active layer being smaller than the electron effective mass of the barrier layer, the spontaneous polarization coefficient of the well layer of the active layer being smaller than the spontaneous polarization coefficient of the barrier layer, and the bandgap width of the well layer of the active layer being smaller than the bandgap width of the barrier layer. The present invention can suppress InN phase separation, segregation, and composition fluctuation in high-In content semiconductor lasers, effectively improve the crystal quality and interface quality of the active layer, effectively enhance the electron-hole recombination efficiency of the active layer, and effectively reduce defects and non-radiative recombination centers, thereby effectively improving the slope efficiency of green lasers.

The present invention discloses an integrated optical chip for augmented reality display and a preparation method thereof, belonging to the field of optoelectronics and display technology. The integrated optical chip includes a first end face coupler, a second end face coupler, and a third end face coupler, and the first end face coupler, the second end face coupler, and the third end face coupler are sequentially provided with a 2×2 multimode interference coupler, a microring filter, a 1×2 multimode interference coupler, an interlayer coupler, a thin-film lithium niobate phase shifter, a phase shifter control electrode, and a grating antenna array structure; wherein, the first end face coupler is used to couple an external red laser into the chip, the second end face coupler is used to couple an external blue laser into the chip, and the third end face coupler is used to couple an external green laser into the chip. This technical solution is used to solve the problem that the display system in the prior art is difficult to simultaneously meet the requirements of lightness, low power consumption, and high resolution.