174 results about "Double crystal" patented technology

The invention discloses a laser frequency stabilization system based on Faraday anomalous dispersion atomic filtering, which is used for carrying out frequency stabilization on phase modulation multi-sideband laser, and comprises a frequency doubling laser unit which is configured to comprise a fundamental frequency seed light source, an electro-optical modulator, a fundamental frequency amplifier and a frequency doubling crystal; the light splitting module unit is configured to split the frequency doubling light into a main output light path and a monitoring light path; the atomic optical rotation filter is located on the monitoring light path and is configured to maintain the purity of the frequency-stabilized laser spectrum through purification treatment under the control of the axial magnetic field and the temperature; the frequency stabilization unit is configured to be a frequency stabilization light path and a servo system, and the frequency stabilization light path is used for obtaining laser frequency information and generating an error signal; the servo system is used for controlling the frequency of the fundamental frequency seed light source according to the error signal feedback. According to the laser frequency stabilization system provided by the invention, the spectrum purification and frequency stabilization precision can be improved, so that high-frequency stability locking is realized.

The invention provides an efficient OPO system with a bicrystal compensation and independent pumping regulation and control structure, and relates to the technical field of laser nonlinear frequency conversion. The device comprises a pump laser, a light source regulation and control unit, an incidence adjustment unit, an OPO resonant cavity and an output separation unit which are sequentially arranged, the OPO resonant cavity comprises a walk-off compensation and frequency conversion module and a tuning module, and the walk-off compensation and frequency conversion module comprises a nonlinear crystal I and a nonlinear crystal II which have opposite cutting angles. And a tuning module is arranged between the nonlinear crystal I and the nonlinear crystal II. The OPO system based on the bicrystal structure has space walk-off angle compensation and pump light independent regulation and control capabilities, and is suitable for constructing near-infrared and intermediate-infrared laser sources with high efficiency and high stability. According to the invention, the optical path structure is flexible, the multi-crystal and multi-band adaptation is supported, and the system compatibility is good; miniaturization and intelligent integration are easy, and industrial application and popularization are facilitated.

The invention provides a temperature compensation method and device for laser frequency doubling, electronic equipment and a storage medium. The method comprises the steps that the initial temperature of a frequency doubling crystal of a frequency doubling laser is determined according to the power of input fundamental frequency light; adjusting the initial temperature, and determining a target temperature corresponding to the maximum value of the frequency-doubled optical power output by the frequency-doubled laser; according to the invention, active following compensation is carried out on the temperature of the frequency doubling crystal, and the temperature of the frequency doubling crystal is controlled at the target temperature, so that the active following compensation is carried out on the temperature of the frequency doubling crystal, thereby enabling the frequency doubling laser to maintain high output power, and further improving the frequency doubling efficiency of the crystal. Therefore, the laser frequency multiplier can quickly reach a steady state in the power switching process, and accurate dynamic control of the laser frequency multiplication system is realized.

The utility model belongs to the technical field of fiber lasers, and particularly relates to a high-efficiency frequency doubling system for a laser. The high-efficiency frequency doubling system for the laser comprises a first lens, a first frequency doubling crystal, a 4f system and a second frequency doubling crystal which are arranged in sequence. According to the high-efficiency frequency doubling system for the laser, the two frequency doubling crystals are used, phase matching is adopted, S polarization light and P polarization light of fundamental frequency light are subjected to frequency doubling in sequence to form P polarization frequency doubling light and S polarization frequency doubling light, two times of frequency doubling of the non-polarization-maintaining fiber laser are achieved through two times of frequency doubling, and high-power green light in the mixed polarization direction is obtained. And under the condition that the infrared fundamental frequency power is kept unchanged, the proportion of S polarization component light to P polarization component light is changed due to the change of the polarization state, but two generated green light beams are complementary, so that the power output is more stable than that of one crystal.

The invention discloses a power stabilizing method and an adjusting system of a frequency doubling laser. The stabilizing method comprises the following steps: acquiring the actual output power of the frequency-doubled laser; acquiring target output power and a set temperature value of the frequency doubling laser; and if the target output power is within the jump range of the output power of the frequency doubling laser, entering automatic power control after delaying for a preset time length. According to the technical scheme provided by the embodiment of the invention, the problems that the optimal temperature of the frequency doubling crystal dynamically changes along with the power and the environment, so that the output power of the frequency doubling laser is unstable and fluctuates are solved.

The invention discloses a miniature integrated infrared gas sensor chip, which belongs to the technical field of sensors, and comprises a first wafer and a second wafer, and the first wafer and the second wafer are connected in a combination manner and form an optical gas chamber; a vent hole is formed above the first wafer, and a reflective film layer is plated on the inner wall of the optical gas chamber and is arranged to only allow infrared light emitted by the infrared light source to pass through; a periodic micro-nano structure is arranged in the optical gas chamber; the surface of the second wafer is covered with an insulating film layer, and an infrared light source and an infrared detector are arranged above the insulating film layer. An optical gas chamber is formed through double-wafer bonding, a periodic micro-nano structure is integrated to enhance interaction between infrared light and gas, environmental interference is suppressed in combination with a double-channel differential detector, and meanwhile stability and selectivity are improved through multi-layer structures such as a reflective film layer, a protective film layer and a composite insulating film layer. And finally, a miniaturized and high-sensitivity gas detection function is realized.

The present invention belongs to the field of plasma electron density measurement and discloses a plasma electron density measurement device and method based on laser wavefront analysis. The device uses a frequency doubling crystal to convert a fundamental frequency laser beam into a coaxial fundamental frequency beam and a second harmonic beam. The two coaxial laser beams produce different wavefront changes when passing through plasma, and these changes are converted into changes in the centroid displacement of a focal light spot through a microlens array. Unlike other measurement methods that require the provision of probe light and reference light, the device does not require a comparison before and after the presence of plasma, and only requires a reference to the difference in the change in the centroid of the focal light spot after two coaxial laser beams of different wavelengths pass through the plasma. The use of the measurement device can eliminate the interference of neutral particles during the experiment and eliminate the difference in laser light in two experiments with and without plasma, thereby achieving synchronous compensation and effectively solving the problem that the reference light path provided in the prior art is easily affected by the environment, thereby limiting the measurement accuracy.

The invention discloses a bamboo-based large-interlayer-spacing homogeneous graphite-like sub-crystal carbon material and a preparation method and application thereof, the bamboo-based large-interlayer-spacing homogeneous graphite-like sub-crystal carbon material comprises a homogeneous graphite-like sub-crystal carbon material, and the homogeneous graphite-like sub-crystal carbon material is characterized by being composed of 3.714.0 large-interlayer-spacing approximately-parallel oriented carbon sheets. When the homogeneous graphite-like subcrystal carbon material is used for a sodium ion battery negative electrode, the initial coulombic efficiency reaches 94.4%, the initial charging specific capacity reaches 353.5 mAh / g, and the performance is comparable with that of a lithium battery graphite negative electrode. The preparation method comprises the following steps: by taking bamboo wood as a precursor, fully inducing a macroscopic bamboo wood continuum to generate an oxygen-containing six-membered ring network intermediate product by taking a graphite container and graphite powder as double seed crystals at low temperature; and inducing an intermediate product with a proper particle size at a high temperature by taking a graphite container as a single crystal seed to prepare the graphite-like subcrystal carbon material with a uniform structure. The method takes a bamboo source as a raw material, is simple in process and low in energy consumption, and has remarkable industrialization potential.

The invention relates to the technical field of all-solid-state lasers, and particularly provides a master-slave pulse delay controllable ultraviolet dual-wavelength double-pulse laser, which comprises a pumping source and a V-shaped folded resonant cavity, and is characterized in that the V-shaped folded resonant cavity comprises an input mirror, a gain medium, a Q-switched crystal, a total reflective mirror, a frequency doubling crystal and an output mirror; wherein the Q-switched crystal performs step-type modulation through a double-step electric signal, the double-step electric signal sequentially comprises a high-voltage stage, a low-voltage stage and a voltage-reducing stage in a modulation period, and the double-step electric signal sequentially generates jump from the high-voltage stage to the low-voltage stage and jump from the low-voltage stage to the voltage-reducing stage in a pumping period. The dual-wavelength master pulse and the dual-wavelength slave pulse are respectively output, and the time delay between the dual-wavelength master pulse and the dual-wavelength slave pulse can be controlled by adjusting the duration of the low-voltage phase. According to the invention, ultraviolet dual-wavelength double-pulse output is realized, and master-slave pulse delay is flexible and controllable.

The invention discloses a lamellar Ni7P3 / bicrystal phase Ni composite material prepared based on tetrabutylphosphonium chloride as well as a preparation method and application thereof, and relates to the technical field of electro-catalytic materials. The invention relates to a lamellar Ni7P3 / bicrystal phase Ni composite material prepared on the basis of tetrabutylphosphonium chloride. The lamellar Ni7P3 / bicrystal phase Ni composite material consists of a Ni7P3 compound and a Ni elementary substance, wherein the Ni elementary substance comprises a face-centered cubic structure crystal form and a hexagonal close packing structure crystal form; and the whole Ni7P3 / bicrystal phase Ni composite material is in a sheet shape. According to the lamellar Ni7P3 / bicrystal phase Ni composite material prepared by the method, stable coexistence of bicrystal phase Ni and lamellar morphology regulation and control are realized by virtue of multiple effects of a solvent of tetrabutyl phosphonium chloride, a phosphorus source and a template; according to the present invention, the overpotential at the current density of 10 mAcm <-2 > is as low as 250 mV, the electrocatalytic oxygen evolution performance is significantly improved through the synergistic effect of the Ni7P3 intrinsic activity, the heterojunction electron optimization, the bicrystal Ni function complementation and the sheet specific surface area increasing, the preparation method is controllable, the material cost is low, the material is suitable for being used as the OER working electrode, and the support is provided for the efficient hydrogen production through water decomposition.

The present invention discloses a system and method for measuring seabed microvibrations based on optical interference. The system includes a laser module, an interferometer module, a frequency doubling module, an optical path integration module, a photoelectric detection module, and a data processing module. The method comprises the following steps: S1: placing the interferometer in a seabed environment to begin measurement; S2: emitting a 1064nm infrared laser, which is divided into a reference light and a measurement light of equal optical path length, and irradiating the measurement light onto the interferometer to form a laser emission path; S3: arranging a first frequency doubling crystal on the laser return path to frequency-double the 1064nm infrared laser into a first green laser of 532nm; S4: arranging a second frequency doubling crystal on the laser return path to convert the unconverted 1064nm infrared laser in S3 into a second green laser of 532nm; S5: integrating the first and second green lasers and interfering with the reference light on the photoelectric detector to obtain the displacement change of seabed vibration. The present invention can detect seabed microvibrations below the micrometer level with high measurement accuracy.

The present invention relates to the technical field of solid light-emitting materials, and provides a glass ceramic, a preparation method therefor and a use thereof. The glass ceramic comprises at least one of a Ba2SiO4:Eu2+ single crystal phase, or a Ba2SiO4:Eu2+ and BaSiO3:Eu2+ double crystal phase. The glass ceramic has excellent stability and light-emitting properties, can be widely used to the field of display or lighting, and is particularly applicable to the fields of outdoor display and high-power lighting.

The invention provides a combined rotating frequency doubling crystal point changing device, a point changing method and a laser. The combined rotating frequency doubling crystal point changing device comprises a refraction lens, a folded cavity mirror, a nonlinear crystal and an end mirror. The refraction lens is rotatably arranged, and fundamental frequency light enters the folding cavity mirror through the refraction lens and is reflected to the nonlinear crystal through the folding cavity mirror; the end mirror reflects fundamental frequency light entering the nonlinear crystal and frequency doubling light generated after the fundamental frequency light enters the nonlinear crystal, and the frequency doubling light is output through the output end of the nonlinear crystal. When the output point of the nonlinear crystal needs to be changed, the refraction lens is rotated by a certain angle, so that the light path of the fundamental frequency light refracted by the refraction lens is changed, and the incidence point of the fundamental frequency light and the output point of the frequency doubling light of the nonlinear crystal are further changed. The operation is greatly saved, and the implementation method is simple and rapid.

The present invention belongs to the technical field of luminescent materials, and discloses a transparent fluorescent ceramic with an adjustable structure, and a preparation method therefor and the use thereof. The transparent fluorescent ceramic comprises at least one of a single MgAl2Si4O12:Eu2+ crystal phase, a single Mg2Al4Si5O18:Eu2+ crystal phase, and dual MgAl2Si4O12:Eu2+ and Mg2Al4Si5O18:Eu2+ crystal phases.

A method to generate a crystal oscillator clock having a duty cycle via a first stage of a clock circuit, double the crystal oscillator clock and inputting the doubled crystal oscillator clock into a phased-locked loop, feed back a phase-locked loop feedback clock, measure a difference in delay between a first edge of the doubled crystal oscillator clock relative to the phase-locked loop feedback clock and a second edge of the doubled crystal oscillator clock relative to the phase-locked loop feedback clock, and adjust the duty cycle of the crystal oscillator clock based on the difference in delay. A device having a detection circuit to measure a difference in delay between first and second edges of a doubled crystal oscillator clock output relative to a phase-locked loop feedback clock, and a controller to adjust the duty cycle of the clock output based on the difference in delay.

The invention relates to a deep blue light random fiber laser based on a femtosecond active phase shift fiber grating, and relates to the technical field of laser. Comprising a 900nm random laser seed light source, a collimator, a first plano-convex lens, a frequency doubling crystal, a temperature control platform, a second plano-convex lens and a beam splitter prism, 900nm random laser enters the collimator; a light beam enters the frequency doubling crystal, the frequency doubling crystal efficiently absorbs 900nm wave band random laser through the CuFe2O4 metal nanoparticle film, and the output end face is plated with a 450nm anti-reflection film; the first plano-convex lens and the second plano-convex lens enable the optimal focusing waist spot of 900nm random laser to be at the central position of the frequency doubling crystal; 900 nm and 450 nm random laser is collimated through a second plano-convex lens, the 900 nm random laser is separated through a beam splitter prism, and 450 nm deep blue light random laser output is obtained. According to the invention, blue light random laser output with high stability, low phase noise and low coherence is obtained.

The invention relates to the technical field of laser, and provides a laser which comprises a sliding assembly arranged between a first laser crystal rod and a reflective mirror of a light gathering cavity, and the first laser crystal rod and the reflective mirror are arranged in the first direction; a KTP frequency doubling crystal and a short-wave pass filter are arranged on the sliding assembly, and laser sequentially passes through the KTP frequency doubling crystal, the short-wave pass filter and the reflective mirror after being emitted from the first laser crystal rod; the sliding assembly can drive the KTP frequency doubling crystal and the short-wave-pass optical filter to move in the second direction, and the second direction is perpendicular to the first direction. According to the scheme, the phase matching position of the KTP frequency doubling crystal and the filtering position of the short-wave pass filter are synchronously adjusted through the sliding assembly, so that the frequency doubling efficiency, the output stability and the power upper limit are improved. And the KTP frequency doubling crystal and the short-wave pass optical filter are integrated on the same assembly, so that optical path angle deviation can be avoided, and meanwhile, the short-wave pass optical filter is always aligned with a frequency doubling optical path, so that wavelength mixing is eliminated.

The utility model discloses a bicrystal probe assembly capable of being quickly disassembled and assembled and automatic wheel flaw detection equipment. The bicrystal probe assembly comprises a base, a probe, an elastic component, an auxiliary plate and a cover plate, the base is provided with two rows of inserting holes which are evenly arranged at intervals in the length direction of the base, and the inserting holes in the upper row and the inserting holes in the lower row are arranged in a staggered mode. The probe is inserted into each insertion hole of the base; the elastic component is arranged between the probe and the base and is used for vertically and upwards jacking the probe; the auxiliary plate is detachably mounted on the base, a plurality of dismounting holes in one-to-one correspondence with the probes are formed in the auxiliary plate, the probes are arranged in the dismounting holes in a penetrating manner, and mounting and dismounting of the probes are completed through the dismounting holes; the cover plates are located above the auxiliary plate, one cover plate corresponds to one probe, through holes are formed in the cover plates, the upper portions of the probes can stretch out of the through holes, and the cover plates are detachably connected with the auxiliary plate. According to the utility model, probe consumption and damage can be effectively reduced, and probe damage can be efficiently treated.

The utility model provides a bimorph for a wireless jacquard comb, which is characterized in that the bimorph comprises a substrate, ceramic chips and an electrode layer, gold-plated copper films are arranged at the end parts of the two surfaces of the substrate, the ceramic chips are adhered to the two surfaces of the substrate, the bottom surfaces of the ceramic chips are electrically connected with the gold-plated copper films, the electrode layer is arranged on the surfaces of the ceramic chips, and the electrode layer is arranged on the surface of the substrate. And the insulating paint is coated on the electrode layer, and the end part of the substrate, which is provided with the gold-plated copper film, is in a wedge-shaped design. The anti-corrosion capability is improved by arranging the gold-plated copper film, and meanwhile, the wedge-shaped design of the end part is convenient to insert and assemble.

The invention belongs to the field of all-solid-state ultrafast laser, and discloses a GHz repetition frequency high-power femtosecond green light and ultraviolet laser generation device and method, and the method comprises the steps: a pumping source outputs fundamental frequency femtosecond laser with the repetition frequency greater than 1GHz; generating femtosecond green light from the fundamental frequency femtosecond laser through a frequency doubling effect; splitting the residual femtosecond laser and the frequency doubling femtosecond green light in the emergent light of the first frequency doubling crystal to obtain a residual femtosecond laser light path and a femtosecond green light path which are parallel to each other; adjusting the time delay of the transmission process of the residual fundamental frequency femtosecond laser to enable the time delay to coincide with the femtosecond green light time in the femtosecond green light path; combining the emergent light of the remaining femtosecond laser light path and the emergent light of the femtosecond green light path; and performing sum frequency on the residual fundamental frequency femtosecond laser and the femtosecond green light after beam combination to generate ultraviolet femtosecond laser. According to the invention, femtosecond green light output with GHz repetition frequency and high output power and ultraviolet femtosecond laser output with GHz repetition frequency and high output power are realized at the same time.

The invention relates to the technical field of frequency doubling in the technical field of laser, in particular to a light-passing end face heat dissipation device of a frequency doubling crystal. Comprising a frequency doubling crystal which comprises a light passing surface and is used for carrying out harmonic conversion under the irradiation of fundamental frequency light; the first-stage heat dissipation medium is a transparent heat dissipation medium, the light transmittance and the heat conductivity of the first-stage heat dissipation medium are higher than those of the frequency doubling crystal, and the diameter of the first-stage heat dissipation medium is larger than that of the light-passing surface so as to cover and contact with at least one light-passing surface for conducting heat generated by the frequency doubling crystal; the second-stage heat dissipation medium is a water-cooling heat sink, is in contact with the non-light-passing surface of the transparent heat dissipation medium and is used for taking away heat conducted by the transparent heat dissipation medium through water circulation; an antireflection film is plated on the light passing surface, in contact with the frequency doubling crystal, of the first-stage heat dissipation medium, or the first-stage heat dissipation medium and the frequency doubling crystal form an integrated structure without an interface through material bonding; the non-light-passing surface of the first-stage heat dissipation medium is provided with a high-reflection film which is used for reflecting the fundamental frequency light and the frequency doubling light, so that the fundamental frequency light passes through the frequency doubling crystal twice to improve the frequency doubling efficiency.

The invention discloses an ultra-short pulse optical parametric oscillator based on a bicrystal structure, and relates to a laser and an assembly, and the oscillator comprises a first beam shaper (2) which is used for shaping idler frequency light (1); a second beam shaper (4) for shaping the pump light (3); a dichroscope (5); the first nonlinear crystal (6) is arranged on a light emitting path of the dichroscope (5), and the first nonlinear crystal (6) is used as an input coupling mirror of the optical parametric oscillator; the second nonlinear crystal (7) is arranged on a light emitting path of the first nonlinear crystal (6), and the first nonlinear crystal (6) and the second nonlinear crystal (7) form a resonant cavity; and the three-direction color mirror (9) is arranged on a light emitting path of the second nonlinear crystal (7) and is used for separating the pump light, the signal light (8) generated by nonlinear frequency conversion and the amplified idle frequency light (1) and transmitting and outputting the idle frequency light. The conversion efficiency of the optical parameter amplification process is improved, and the overall amplification performance of the optical parameter amplifier is guaranteed.

A laser-induced Raman and fluorescence spectroscopic test system includes a laser module, a harmonic beamsplitter, a frequency-doubling crystal, a first cavity mirror, a sample cell, a second cavity mirror, and a spectroscopic detection unit. A laser beam output by the laser module sequentially passes through the harmonic beamsplitter, the frequency-doubling crystal, and the first cavity mirror. Two sides of the harmonic beamsplitter are plated with a highly transmissive film and a highly reflective film, and the harmonic beamsplitter reflects a laser beam of a required wavelength to the sample cell. The second cavity mirror is configured for returning a laser beam from the sample cell. The harmonic beamsplitter, the first cavity mirror, the second focusing lens, and the second cavity mirror form a dual-beam waist laser resonator cavity. The first cavity mirror and the second cavity mirror are spherical mirrors and are plated with different highly reflective films.

An LED lamp device comprises a lamp string formed by connecting forward and reverse bi-crystal LED lamp beads in series, an alternating current input end for supplying alternating current to the lamp string and a voltage reduction device arranged at one end of the lamp string, and the voltage reduction device is a polyester film capacitor C1. Due to the fact that the combination of the lamp string formed by connecting the forward and reverse bi-crystal LED lamp beads in series and the voltage reduction device is applied, AC input can be directly used, rectification is not needed, and the effect that a light source does not shake can be achieved; pins of the LED lamp beads cannot be electrolyzed, so that the safety and the service life of the product are improved; the use of elements such as diodes is reduced, so that the production process is simplified, and the product cost is reduced; due to the fact that the LED lamp beads are combined through forward and reverse double crystals, the heat dissipation area of the LED lamp beads is larger, the heat dissipation effect is better, and the service life of the LED lamp beads is prolonged. The positive half wave and the negative half wave of the alternating current are effectively utilized, and the power factor of the product is higher.

The invention relates to the technical field of solid lasers, in particular to a large-energy green laser. The laser comprises a first pumping source, a first pumping coupling device, a second pumping source, a second pumping coupling device, a resonance assembly, a first frequency doubling crystal, a second frequency doubling crystal, a Q-switching device, a first crystal and a second crystal. The resonant assembly is used for forming a laser resonant cavity and further comprises a compensation device. According to the large-energy green laser provided by the invention, the thermal lens effect of the laser crystal can be weakened through the double-pumping double-crystal, so that the fundamental frequency light can be better amplified. And the arranged compensation device can also improve the overall thermal management of the laser by compensating the thermal lens effect, and is beneficial to outputting stable and high-energy laser.

The invention relates to the technical field of semiconductor photoelectricity, in particular to a laser-induced oxygen-zinc-magnesium nano stripe solar-blind ultraviolet photoelectric detector and a preparation method thereof. The method comprises the steps of cleaning a substrate; taking a ZnO-MgO composite target material as a sputtering source, and depositing an MgZnO thin film on the pretreated substrate by adopting a radio frequency magnetron sputtering technology; a femtosecond laser processing system is built, original laser emitted by a femtosecond laser device is subjected to frequency doubling through a frequency doubling crystal, laser pulse energy is adjusted through a polarization adjusting assembly, laser beams are focused on the surface of the MgZnO thin film on a displacement platform through an objective lens, MgZnO nano stripes are obtained through scanning processing, and surface cleaning is carried out; and evaporating a metal electrode layer on the surface of the MgZnO nano stripe by adopting a vacuum evaporation coating technology. The method has the advantages that the operation is simple, convenient and reliable, and self-assembly and form regulation and control of the nanostructure can be accurately realized; controllable doping of the Mg element can be realized by regulating and controlling the components of the target material; the process is efficient and fast, and the controllability is high.

The utility model provides a frequency-doubled laser linewidth narrowing device. The device comprises a pumping module and a laser resonant cavity, the pumping module is used for providing linearly polarized light in a specific polarization direction to a light path; the laser resonant cavity is internally provided with a gain medium, at least one birefringence optical filter and a frequency doubling crystal which are sequentially arranged along an optical path, and the at least one birefringence optical filter is inserted into the optical path at a Brewster angle; wherein the linearly polarized light is focused in the gain medium, the central wavelength of the linearly polarized light is the same as the absorption peak wavelength of the gain medium, and the polarization direction of the linearly polarized light is the same as the maximum absorption direction of the gain medium. According to the invention, the birefringence optical filter (group) inserted into the laser resonant cavity can be specifically adjusted, so that narrow-band filtering can be conveniently and quickly realized in various intracavity frequency doubling lasers, and compared with the prior art, the introduced power loss is relatively small.

The application is suitable for the technical field of optical devices, and provides an optical assembly, a laser and a laser processing device. The optical assembly comprises, in sequence along an outgoing light direction, a resonant cavity, an optical diffraction element, a frequency doubling crystal and a Q switch. The resonant cavity is used for emitting a light beam. The optical diffraction element is used for homogenizing the light beam. The frequency doubling crystal is used for modulating the frequency of the light beam. The Q switch is used for adjusting the direction of the light beam to control whether the light beam is emitted. The resonant cavity, the optical diffraction element, the frequency doubling crystal and the Q switch in the embodiment of the application are arranged in sequence along the outgoing light direction, so that the stability of the light beam emitted from the Q switch can be improved.

The invention relates to the technical field of ultrasonic flaw detection, in particular to an ultrasonic flaw detection method and system for cathode roller raw materials for copper foils, and the method comprises the following steps: uniformly selecting each position point on the curved surface of a cathode roller, and sequentially collecting ultrasonic signals received by each position point at each deflection angle by using a twin-crystal probe; determining a time-frequency characteristic coefficient of each ultrasonic signal; acquiring multi-angle signal distribution characteristics of each position point; determining a spatial distribution coefficient of each ultrasonic signal; and in combination with the time-frequency characteristic coefficient and the spatial distribution coefficient, correcting a threshold value in a wavelet denoising algorithm, denoising each ultrasonic signal, and carrying out ultrasonic flaw detection on the cathode roller by utilizing all the denoised ultrasonic signals. Therefore, the ultrasonic flaw detection precision of the cathode roller is improved.