18results about How to "High damage threshold" patented technology

The invention discloses a surface plasmon-based 3 [mu] m waveband solid femtosecond laser, comprising: a fiber laser pumping source for emitting a laser beam; the resonant cavity comprises an input mirror group and a surface plasmon light modulation element; the laser beam can be input into the surface plasmon light modulation element through the input lens group; and an output mirror; wherein the laser beam is reflected to the input mirror group through the surface plasmon light modulation element, so that the laser beam can be output through the output mirror. The laser prepared by the invention has the advantages of high damage threshold, strong nonlinear modulation characteristic, high stability and the like, and effectively breaks through the barrier in the prior art.

The invention discloses a femtosecond laser pulse time shaping system. The system comprises a laser, and a polarization assembly, a polarization beam splitter, a 1 / 4 wave plate and a first semi-transparent and semi-reflective mirror which are sequentially arranged along the laser direction of the laser, the polarization assembly is used for converting the initial femtosecond laser pulse generated by the laser into linearly polarized light; the polarization beam splitter is used for highly transmitting the linearly polarized light entering the polarization beam splitter and highly reflecting the linearly polarized light perpendicular to the vibration direction of the incident linearly polarized light; the polarization beam splitter, the 1 / 4 wave plate and the first half-transparent and half-reflecting mirror form a time shaping device which is used for performing time shaping on femtosecond laser; the initial femtosecond laser pulse is subjected to polarization modulation of the polarization assembly and time shaping processing of the time shaping device, and finally a double-pulse sequence is output. The time shaping system is easy to construct and has a high damage threshold value, high-power processing and light path limitation of the time shaping system can be solved, and the time shaping system has important significance in the field of femtosecond laser application.

The invention discloses a multi-refractive-index nested hollow-core anti-resonance optical fiber and a preparation method thereof, and relates to the technical field of optical communication. The hollow-core anti-resonance optical fiber sequentially comprises an air core, a plurality of first-stage cladding tubes, a plurality of second-stage cladding tubes, a plurality of third-stage cladding tubes and a peripheral cladding tube from inside to outside. Wherein the first-stage cladding tube and the peripheral cladding tube are fixed in an internally tangent manner, the second-stage cladding tube and the first-stage cladding tube are fixed in an internally tangent manner, and the third-stage cladding tube and the second-stage cladding tube are fixed in an internally tangent manner. The design of the optical fiber breaks through the limitation of a traditional uniform-refractive-index hollow-core anti-resonance optical fiber, the cladding tube is composed of a high-refractive-index material and a low-refractive-index material, and effective regulation and control of light wave transmission are achieved. According to the hollow-core optical fiber, the ultra-low loss level can be maintained even under the bending condition while the ultra-low loss is maintained, the preparation process is simple and convenient, reduction of the production cost and improvement of the production efficiency are facilitated, and the hollow-core optical fiber has good industrial application prospects.

The utility model belongs to the technical field of optics, and particularly provides a diaphragm adjusting device which comprises a base and a diaphragm. The base is connected with a bracket; the bracket is provided with a mounting through hole; the diaphragm is movably mounted in the mounting through hole; the support is provided with an adjusting assembly used for driving the diaphragm to move in the installation through hole, and the moving direction of the diaphragm in the installation through hole is parallel to the vertical plane of light beam propagation. According to the diaphragm adjusting device provided by the utility model, complicated X-axis and Y-axis adjusting mechanisms are omitted, and the diaphragm adjusting device is small in size, low in cost and convenient to use. The position of the diaphragm can be determined only through the adjusting screw and the elastic plunger, the diaphragm slides along the matching surface of the diaphragm base when the adjusting screw is adjusted, and high-precision adjustment of the diaphragm is achieved. In addition, the light passing area of the diaphragm can be polished and chamfered, the damage threshold value of the diaphragm is increased, the aperture can be made smaller, and the volume of a fundamental mode is limited.

The utility model discloses a metasurface unit structure and a metasurface formed by the metasurface unit structure, and belongs to the technical field of nonlinear optics. The metasurface unit structure comprises a substrate layer and a dielectric layer which are arranged from bottom to top, wherein a convex groove or a concave groove is formed in the dielectric layer. The sections of the substrate layer and the dielectric layer are square, and the sizes are nanoscale; the substrate layer is made of SiO2, and the dielectric layer is made of DAST crystals. The metasurface is formed by periodically arranging a plurality of metasurface unit structures. According to the utility model, the convex or concave grooved structure, the substrate layer with low refractive index, the DAST dielectric layer which has a higher damage threshold and is easy to process and the like are introduced, so that the loss can be reduced, the asymmetry degree can be conveniently adjusted by changing the grooved structure, the quality factor Q can be changed, the local electric field distribution can be optimized, and different application requirements can be met.

The present invention relates to the technical field of saturable absorbers, and in particular to a saturable absorber based on tin oxide nanoparticles, a preparation method thereof, and a ring cavity fiber laser. The ring cavity fiber laser is composed of a pump source and a ring laser resonant cavity. The ring laser resonant cavity is composed of a wavelength division multiplexer, an erbium-doped optical fiber, a polarization light isolator, a saturable absorber, a polarization controller, and an optical splitter connected in sequence. The pump source is connected to the input end of the wavelength division multiplexer. The saturable absorber is a saturable absorber based on a mixture of tin oxide nanoparticles and a film-forming agent, or a saturable absorber based on tin oxide nanoparticles deposited on the surface of a tapered optical fiber, a D-type optical fiber, or a cladding-corroded optical fiber, or a saturable absorber based on tin oxide nanoparticles filled in the air hole cladding of a photonic crystal optical fiber. The present invention can provide a new solution for the development of ultrashort pulse fiber lasers.

The invention relates to the field of semiconductor technology, and proposes a method for passivating the cavity surface of a GaN-based EEL laser chip, comprising the following steps: S1, cavity surface dehumidification: heating the cavity surface of a bar strip to remove the moisture; S2, cavity surface cleaning: continuing to increase the temperature, and introducing gas to bombard the cavity surface; S3, cavity surface annealing: continuing to increase the temperature, and introducing gas to bombard the cavity surface, and then annealing to form a transition layer; the gas in steps S2 and S3 is one or more of O2, N2 and H2; S4, cavity surface passivation: transferring the bar strip into a passivation chamber, maintaining the annealing temperature, introducing one or more of O2, O3 or N2 to bombard the cavity surface, and forming an Al2O3, AlON or AlN single crystal film on the surface of the transition layer. The invention adopts high-temperature annealing to form a transition layer on the cavity surface. Compared with CaN, the mismatch rate between the transition layer and Al2O3, AlON and AlN is lower, it is easier to grow a single crystal film, and it will not cause light absorption of the cavity surface, thereby achieving the technical effect of increasing the cavity surface damage threshold and extending the service life of the laser.

The invention provides a JGS1 substrate antireflection film and a preparation method and application thereof. According to the JGS1 substrate antireflection film provided by the invention, the JGS1 quartz glass substrate with relatively high transmittance in a deep ultraviolet band is adopted to replace a calcium fluoride substrate, so that the cost is greatly reduced; meanwhile, a new film system design is adopted on the JGS1 quartz glass substrate: an F-SiO2 thin film layer is arranged on the JGS1 quartz glass substrate, and then an antireflection film layer is arranged; adding a protective layer on the antireflection film layer; according to the film system design, the adsorption force between the antireflection film layer and the JGS1 quartz glass substrate can be increased, and the mechanical strength of the film layer is improved; the deposition of organic matters is effectively prevented, and the JGS1 substrate antireflection film has a higher heat damage threshold value while the ultrahigh transmittance (greater than 99.5%) in a deep ultraviolet band (193nm) is realized.

This application relates to a special optical fiber, comprising a core layer and an outer cladding layer arranged sequentially from the inside to the outside along the radial direction of the special optical fiber, wherein the core layer includes a silicon nitride layer. The special optical fiber provided by this application incorporates a silicon nitride layer, disposed within the outer cladding layer. Silicon nitride has excellent thermal conductivity, enabling rapid dissipation of heat accumulated within the core / cladding layer, preventing localized hotspots that could degrade fiber quality and increasing the damage threshold. Silicon nitride remains stable at temperatures above 1200°C in an inert atmosphere and is unlikely to react with other substances, completely solving the problem of polymer carbonization. In terms of mechanical and chemical protection, silicon nitride acts as a chemical barrier. The dense, non-porous structure of the silicon nitride film gives this special optical fiber resistance to salt spray and hydrogen sulfide corrosion. Silicon nitride is a more effective Compton scatterer than silicon dioxide, reducing gamma photons incident deep within the optical fiber and improving its irradiation performance.

The invention belongs to the field of attosecond pulses, and particularly relates to a dispersion compensation and separation method and device for soft X-ray water window wave band attosecond pulses. The dispersion compensation device comprises a vacuum cavity and a liquid film generation mechanism, the working end of the liquid film generation mechanism is arranged in the vacuum cavity and used for outputting a working medium to generate a liquid film with the uniform and adjustable thickness. The separation device comprises a vacuum cavity and a liquid film generation mechanism, the working end of the liquid film generation mechanism is arranged in the vacuum cavity and used for outputting a working medium to generate a liquid film which is non-uniform and adjustable in thickness. The dispersion compensation and separation device comprises a vacuum cavity and two liquid film generation mechanisms, and the working ends of the two liquid film generation mechanisms are respectively arranged in the vacuum cavity and are used for respectively outputting working media to generate liquid films with non-uniform and adjustable thicknesses. Dispersion compensation or separation of attosecond pulses can be independently achieved through the liquid film, and dispersion compensation and separation can also be achieved at the same time.

The present invention belongs to the field of laser technology, and provides a high repetition rate 193nm laser based on LD pumped alexandrite crystal, which includes an LD pump source, an alexandrite laser oscillator and a nonlinear frequency conversion module; the LD pump source is used to generate laser light and input it into the alexandrite laser oscillator; the alexandrite laser oscillator includes a first dichroic mirror, an alexandrite crystal, a first plano-convex lens, a birefringent filter, a Q-switched device, a first quarter wave plate and an output coupling mirror arranged in sequence along the optical path; the alexandrite laser oscillator is used to generate a fundamental frequency light source; the fundamental frequency light source is sequentially input into the nonlinear frequency conversion module through a first half wave plate and a second plano-convex lens to obtain a 193.4nm laser. The entire system is a fully solid-state structure, and has the characteristics of good pump source stability and high integration, short fundamental frequency light source wavelength, less nonlinear conversion times, high overall electro-optical conversion efficiency and low overall system cost.

The invention provides a waveguide and a higher harmonic generation device. The waveguide and the higher harmonic generation device comprise a waveguide body; the waveguide body is in a cylinder shape, a first through hole is formed in the waveguide body and penetrates through the waveguide body in the length direction of the waveguide body, and a film layer used for reflecting light is arranged on the inner surface of the first through hole. The waveguide is applied to a higher harmonic generation device, the refraction and scattering loss of exciting light can be greatly reduced through the high reflectivity of the film layer to the exciting light, the action area of a laser strong field is effectively concentrated, and the higher harmonic process is limited in the first through hole, so that the generation efficiency of the higher harmonic can be greatly improved, and the generation efficiency of the higher harmonic is improved. And the damage threshold of the hollow waveguide is improved.

The embodiment of the invention discloses an ultraviolet laser adjustable beam expanding optical system and a beam expanding lens, and relates to the field of optics. The system sequentially comprises a first lens group with positive diopter, a second lens group with negative diopter, a third lens group with negative diopter and a fourth lens group with positive diopter which are arranged along the same optical axis along the incident direction of a laser beam, wherein the positions of the first lens group and the fourth lens group are fixed in the system, the second lens group can move along an optical axis so as to adjust the beam expanding magnification of a light beam, and the third lens group can move along the optical axis so as to perform collimation compensation of a laser beam. By arranging the movable second lens group and the third lens with the compensation function, the beam expanding multiple of the optical system is variable, and the output light beam meets the requirements of high collimation and high image quality.

The application discloses a quartz crystal-based adjustable strong-field terahertz light source and an adjusting method thereof, and belongs to the optical field. The terahertz light source is designed by using the high damage threshold and low absorption characteristics of the quartz crystal in the terahertz wave band. In addition to the femtosecond laser, the beam-reducing system, the grating, a pair of X-direction achromatic column lenses, the 1 / 2 wave plate and the quartz crystal required by the general inclined wave front, the terahertz light source further comprises a pair of Y-direction column lenses. One of the X-direction achromatic column lenses is replaced by a double-lens combined lens. The focal length of the combined lens is finely adjusted by adjusting the lens spacing of the combined lens. The grating front mirror is placed on a translation stage to adjust the grating incidence angle. The inclination angle of the quartz crystal is 43 degrees, and the terahertz light is emitted along the inclined surface of the quartz crystal. The application adjusts the THz center frequency from 2 to 4 THz and the terahertz spectrum width from 0 to 6 THz by simultaneously adjusting the focal length of the combined lens, the grating incidence angle and the emission angle, and realizes the terahertz generation efficiency of nearly 0.04%.

The invention discloses a congruent molten halogen vanadate compound, a vanadium zinc rubidium bromide nonlinear optical crystal as well as a preparation method and application of the vanadium zinc rubidium bromide nonlinear optical crystal. The chemical formula of the vanadate compound is Rb3ZnV4O12Br, the vanadium zinc rubidium bromide nonlinear optical crystal Rb3ZnV4O12Br can be prepared through the vanadate compound, the obtained nonlinear optical crystal is of a non-centrosymmetric structure and belongs to an orthorhombic system, the space group is C mm < 2 >, unit cell parameters are # imgabs0 # imgabs1 #, alpha is equal to 90 degrees, beta is equal to 90 degrees, gamma is equal to 90 degrees, and Z is equal to 2. The nonlinear optical crystal provided by the invention has the characteristics of high damage threshold, large nonlinear optical effect, high electro-optic coefficient, wide transmission range, easiness in crystal growth and the like, and the frequency doubling effect of the nonlinear optical crystal is 0.7-1.4 times that of an AGS crystal. The invention also discloses application of the nonlinear optical crystal in preparation of laser nonlinear optical composite functional devices, electro-optical crystal devices, lasers and other devices.

The invention provides a method for inhibiting end face failure of a laser, belongs to the technical field of semiconductor lasers, and is used for solving the technical problem that the electric field intensity at the junction of an epitaxial material and an optical coating material of the laser is too large. The method comprises the following steps: (1) cleaving a semiconductor laser wafer into bars, and evaporating first film layers on front cavity surfaces and rear cavity surfaces of the bars respectively; (2) evaporating an antireflection film on the front cavity surface of the bar, and evaporating a high-reflection film on the rear cavity surface of the bar; and the thickness of the first film layer is the thickness when the electric field intensity at the junction of the laser epitaxial material and the optical coating material is reduced to zero. According to the invention, the electric field intensity at the junction of the laser epitaxial material and the optical coating material is reduced to zero, the design of zero electric field intensity reduces non-radiative recombination excited by the electric field, and the purposes of improving the end surface damage threshold and improving the reliability are achieved.

This application belongs to the field of laser regenerative amplification, specifically disclosing a high-energy pulse train regenerative amplifier based on electro-optic modulation programmable. This application applies phase disturbance and amplitude modulation to the pulses using an electro-optic modulator (EOM), coupled with an active feedback system based on a spectrometer and piezoelectric ceramic (PZT). The electro-optic modulator and PZT are matched in response speed; the bandwidth of the EOM must be sufficiently high to handle the independent modulation of each pulse, while the bandwidth of the PZT needs to be able to track cavity length changes caused by environmental disturbances. Because the electro-optic modulator can precisely and rapidly control the phase and amplitude of each pulse, disrupting the fixed phase relationship between pulses, it avoids spectral modulation effects caused by coherent superposition, improves spectral uniformity, and achieves uniform and efficient amplification of multiple pulse trains, significantly improving energy extraction efficiency and system output stability.

The invention discloses a hybrid mode-locked picosecond laser based on nonlinear polarization rotation and composite materials, belonging to the field of passive mode-locked fiber lasers; the laser comprises a pump source, and a wavelength division multiplexer, an ytterbium-doped fiber, an SM-28e single-mode fiber, a polarization controller 1, a polarization-dependent isolator, a polarization controller 2, a coupler and a composite saturable absorber mode-locker are sequentially arranged in series in the light emission direction of the pump source; the polarization-dependent isolator is sandwiched between the polarization controller 1 and the polarization controller 2 to form a nonlinear polarization rotation structure, and realizes a double nonlinear absorption effect with the composite saturable absorber mode-locker; the film in the composite saturable absorber mode-locker is composited by single-walled carbon nanotubes and molybdenum disulfide solution, obtains more excellent optical properties on the basis of the initial properties of a single material, and can better lock the mode; and under the joint action of the nonlinear polarization rotation structure, the output performance of the ultrashort pulse laser is further improved.