452 results about "Cw laser" patented technology

The invention relates to a phase-sensitive optical time domain reflectometer based on multi-frequency reference switching. Continuous laser generated by a continuous laser is divided into a local path and a detection path through an optical coupler; the local path is input to the polarization coherent receiving module, the detection path is incident to a light intensity modulator driven by the signal generation circuit module, and the light intensity modulator is converted into a multi-frequency pulse laser sequence with intensity modulation; the multi-frequency pulse laser sequence enters the sensing optical fiber to be measured through the optical circulator; generated Rayleigh backscattered light and local continuous laser are subjected to beat frequency coherent receiving in a polarization coherent receiving module through a circulator; and the signal acquisition circuit adopts a demodulation algorithm to compensate phase drift and sensitivity difference of detection pulse demodulation signals with different frequencies so as to realize dynamic strain sensing. Compared with the prior art, the phase drift and the sensitivity difference between the frequencies are extracted to realize the compensation of the interleaved signals, and the method does not depend on the fixed reference frequency, so that the robustness and the adaptability of the system in a complex environment are remarkably enhanced.

The invention discloses an array type optical fiber ultrasonic imaging system based on multi-path delay parallel detection, and belongs to the technical field of ultrasonic detection and imaging. The main working process of the system is as follows: continuous laser output by a laser is modulated into pulse laser to be transmitted to an optical fiber ultrasonic detector array, and ultrasonic waves emitted by an ultrasonic wave generating device act on each detection array element to cause the property change of a detection optical signal; through multi-path time delay with the optical fiber as the medium, the detection optical signal forms different transmission time in each channel, is distinguished in a time division mode and is combined into a single path to be output. After photoelectric conversion, electric signals containing multi-channel detection information are collected in parallel, the signals are analyzed at a terminal processor by means of an imaging algorithm with an array parallel architecture, information of a to-be-detected target is obtained, and image reconstruction is completed. The array type optical fiber ultrasonic imaging system has the advantages of being accurate and rapid in scanning detection, simple and compact in system structure and efficient and high-quality in image reconstruction, and large-scale and low-cost array type optical fiber ultrasonic imaging is achieved.

The invention relates to a phase-sensitive optical time domain reflectometer based on a parallel frequency division multiplexing sequence. Continuous laser is divided into a local path and a detection path through an optical coupler; the local path is input to the polarization coherent receiving module, the detection path is converted into a pulse laser sequence with intensity modulation through a light intensity modulator driven by a radio frequency signal provided by the signal generation circuit module, and the radio frequency signal is composed of two frequency division multiplexing sequences with difference; the pulse laser sequence enters the sensing link to be measured to generate Rayleigh backscattered light, and the Rayleigh backscattered light and local continuous laser are subjected to beat frequency coherent receiving through a circulator; and the signal acquisition circuit is used for sampling and analyzing the interference signal, and performing frequency domain comparison on an interleaving result of the two frequency division multiplexing pulse sequences to eliminate a harmonic frequency and retain a real strain signal frequency. Compared with the prior art, the non-harmonic strain signal measurement is realized, the high-frequency response performance and the high-precision strain measurement capability are excellent, and meanwhile, the long-distance coverage capability is also realized.

The invention discloses an underwater navigation positioning method and system based on supercontinuum laser intensity correlation. The system comprises a master control system, a transmitting end underwater base station and a receiving end underwater carrier. The method comprises the following steps: firstly, a main control system generates a super-continuum laser signal with pseudo-random code information, the super-continuum laser signal is separated into optical signals of different wavelength channels through a light splitting module, and the optical signals are respectively sent to underwater base stations uniquely corresponding to the wavelength channels and are emitted; then the underwater carrier receives optical signals from a plurality of base stations, identifies a signal source base station according to wavelength identification, performs correlation operation with a locally copied pseudo-random code sequence, determines signal arrival time TOA and calculates a pseudo-range; and finally, resolving the three-dimensional coordinate and local clock error result of the underwater carrier by combining the pseudo-ranges, absolute positions and transmission delays of the underwater carrier and the at least four base stations. According to the invention, high-precision and high-robustness absolute positioning of the underwater environment is realized, and the reliability of long-time positioning and navigation of the underwater robot is enhanced.

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

The invention discloses a continuous scanning half-wave sampling system for a multi-dimensional coherent spectrum, which comprises a continuous laser, continuous laser output by the continuous laser and femtosecond laser pulse output by an ultra-short femtosecond laser pulse generation device are combined and then split, and modulation and time delay are respectively carried out; the multi-dimensional coherent femtosecond laser pulse sequence is used for exciting a fluorescence signal generated by a sample and converting the fluorescence signal into a first electric signal, and the obtained continuous laser carrying different modulation frequencies is converted into a second electric signal; and demodulating the second electric signal by taking a total mixing signal obtained by mixing the multiple paths of modulation signals as a reference, and demodulating the first electric signal by using the second electric signal. The invention further discloses a continuous scanning half-wave sampling method for the multi-dimensional coherent spectrum. The half-wave sampling method is utilized to accurately calibrate optical time delay so as to obtain the multi-phase multi-dimensional coherent spectrum. The sampling step length breaks through the limitation of the minimum sampling step length of traditional stepping collection, and the sampling bandwidth is remarkably improved.

The invention discloses a flying cleaning process for a thinning area of a battery pole piece, and relates to the technical field of laser processing. The method comprises the following steps: S1, selecting a homogenized DOE lens for a pulse laser and / or a continuous laser, arranging the homogenized DOE lens on an external light path, adjusting the angle of the lens to enable laser to vertically and smoothly pass through the center of the homogenized DOE lens, and rotating the homogenized DOE lens to adjust the angle of a shaped light spot to an area to be cleaned after light is emitted; s2, cleaning upper-layer graphite of the coating layer of the thinned area by adopting a continuous laser / pulse laser until the copper foil is slightly exposed, and uniformly cleaning the thinned area; and S3, cleaning the residual bottom layer graphite of the coating layer in the thinned area by using a pulse laser. The cleaning process is simple and reliable, the yield of the laser cleaning thinned area can be effectively improved, the lossless cleaning effect is achieved, and meanwhile the laser cleaning efficiency can be remarkably improved.

The invention discloses a cascade up-conversion-based photosensitive material and a preparation method thereof. The cascade up-conversion-based photosensitive material comprises a photopolymerization material, holmium-ytterbium rare earth nanoparticles and a triplet-state up-conversion material, the photopolymerization material comprises a photoinitiator and a polymerization monomer; the triplet-state up-conversion material comprises a sensitizer and an annihilation agent; the polymeric monomer adopts a liquid monomer or oligomer containing more than 3 active groups. Through the synergistic effect of the photopolymerization material, the holmium-ytterbium rare earth nanoparticles and the triplet state up-conversion material, a brand new cascade up-conversion mode is formed, the dispersivity of up-conversion photopolymerization of traditional thulium-ytterbium nanoparticles is overcome, and low-power, low-cost and high-precision continuous laser micro-nano structure processing is realized.

The invention provides a two-dimensional composite laser cleaning device, and relates to the technical field of laser cleaning, the two-dimensional composite laser cleaning device comprises a two-dimensional galvanometer scanning combination package, a pulse laser collimating lens, a light path collimating turn-back package, a continuous laser collimating lens, a plane field lens and a working platform, the pulse laser collimating lens and the continuous laser collimating lens are connected to the two ends of the light path collimation turn-back package respectively, a mechanical arm switching module is arranged on the light path collimation turn-back package, the pulse laser collimating lens is used for being connected with a nanosecond pulse laser, the continuous laser collimating lens is used for being connected with a continuous laser, and the mechanical arm switching module is used for being connected with the nanosecond pulse laser. And the light path collimation turn-back packaging is used for carrying out collimation and compression combination on the pulse laser and the continuous laser so as to output a parallel composite light beam. According to the invention, field curvature and distortion can be effectively suppressed, and the phenomenon of non-uniform energy of light beam scanning is improved.

The invention discloses a wire bonder transducer, a wire bonder and a vibration amplitude detection and calibration method, and realizes non-contact and high-sensitivity amplitude detection of a vibration part of the transducer by integrating a laser interference detection part in the wire bonder transducer. Continuous laser with a stable wavelength is output through the laser, signal light and reference light are split through the optical splitter, the signal light irradiates the vibration part of the transducer and is reflected, the reference light and the reflected light are combined in the beam combiner to form interference fringes, and finally a phase change signal is collected through the photoelectric detector. According to the invention, the micron-sized vibration displacement of the transducer in the working state can be extracted in real time with high precision. Compared with a traditional judgment mode, the method has the advantages that an objective and quantifiable detection means is provided, the precision and the automation degree of transducer performance consistency evaluation are effectively improved, the method can be widely applied to production line detection, equipment calibration, online quality control and other scenes of wire welding equipment, and the method has important significance in guaranteeing the welding stability and improving the packaging yield.

The invention discloses an anti-unmanned aerial vehicle or unmanned aerial vehicle cluster device and method, and relates to the technical field of anti-unmanned aerial vehicles. The device comprises a radar detection module, a data processing unit, a control system, a pulse laser transmitter, a light beam control and focusing system, a cooling system and a power supply system. According to the device, large-energy pulse laser is integrated into a laser anti-unmanned aerial vehicle device, the pulse laser can release extremely high peak power in an extremely short time, a strong photo-thermal and light pressure effect is instantly generated, an unmanned aerial vehicle body is instantly punctured, the destroying time is greatly shortened, and the problem that the efficiency is low in an existing continuous laser anti-unmanned aerial vehicle technology is solved.

The invention relates to the technical field of liquid phase chips, in particular to an autoantibody spectrum detection platform based on a liquid phase chip technology, and the method comprises the following steps: preparation and functionalization of quantum dot encoding microspheres; the core-shell structure quantum dots are used as coding elements, and fluorescence coding combination of more than 1000 is realized by regulating and controlling the size, 3-10nm, Mn < 2 + > doping and spatial distribution of the quantum dots. The method has the advantages of super multi-target detection, super sensitivity, strong anti-interference capability and intelligent analysis, in the actual process, the core-shell structure quantum dots are adopted as coding elements, more than 1000 fluorescent coding combinations are realized by regulating and controlling the size, doping and spatial distribution of the quantum dots, high-density coding is realized by utilizing three-parameter coding and an orthogonal decoupling algorithm, and the method is suitable for large-scale industrial production. More types of autoantibodies can be detected at the same time, so that the detection flux is improved; the surfaces of the quantum dots are coated with silicon dioxide layers, and the fluorescence intensity is attenuated by lt under continuous laser irradiation; and the stability of a fluorescence signal in the detection process is ensured.

The invention discloses a coaxial double-beam welding method and coaxial double-beam welding equipment, and relates to the technical field of metal laser welding methods.The coaxial double-beam welding method comprises the following steps that S1, a to-be-welded workpiece is pretreated, and then the to-be-welded workpiece is fixed; s2, the continuous laser beam and the pulse laser beam are coaxially coupled into a composite laser beam, the spraying direction of molten pool shielding gas is adjusted, and the sprayed molten pool shielding gas is aligned to a molten pool; s3, the composite laser beam is adjusted, and the spot diameter d of the composite laser beam irradiating the molten pool is controlled; s4, the average output power and the defocusing amount of the continuous laser are set to be delta z2, the average output power and the defocusing amount of the pulse laser are set to be delta z2, and the frequency is f and the pulse width; and S5, welding is conducted, and meanwhile molten pool shielding gas is sprayed to the molten pool till welding is finished. Continuous laser and pulse laser are coaxially coupled to form a composite laser beam, the composite laser beam jointly acts on a molten pool, the temperature distribution gradient is accurately controlled by regulating and controlling the coaxial double-beam heat source state, and therefore the problem of thin plate welding deformation is solved.

The invention discloses a device and method for testing performance degradation of a deep ultraviolet fused quartz material, and the method comprises the steps: employing a continuous laser beam with the wavelength of 213nm as a detection light beam, and simultaneously monitoring the transmittance change of the detection light beam after the detection light beam passes through a deep ultraviolet laser irradiation region of the deep ultraviolet fused quartz material and the instantaneous change of the light intensity of a light beam central region; the color center defect concentration change of the deep ultraviolet fused quartz material caused by deep ultraviolet laser irradiation and the absorption change of the deep ultraviolet laser irradiation wavelength are obtained, and the transmittance change of the irradiation laser beam transmitting the deep ultraviolet fused quartz material is monitored at the same time; the performance degradation data of the deep ultraviolet fused quartz material under the irradiation of the deep ultraviolet laser and the contribution of the color center defect generated by the irradiation of the deep ultraviolet laser to the performance degradation are obtained. According to the invention, the contribution of color center defects to performance degradation can be distinguished, the performance recovery mechanism of hydrogen can be measured, and the measurement sensitivity of thermal lens signals can be effectively improved.

The invention discloses a special-shaped hole machining system and a special-shaped hole machining method. The machining method of the special-shaped hole comprises the steps that quasi-continuous laser is adopted for machining in a machining target to form a prefabricated hole; carrying out scanning processing on the prefabricated hole by adopting ultrafast laser according to a layer-by-layer scanning removal mode so as to process the prefabricated hole into a special-shaped hole; and the straight round section of the special-shaped hole is subjected to fine trimming treatment in any one of ultrasonic-assisted mechanical tool cutting machining or ultrasonic-assisted electric spark machining and electro-hydraulic beam machining, so that the taper is eliminated. According to the special-shaped hole machining system and the special-shaped hole machining method provided by the embodiment of the invention, machining of complex special-shaped holes can be achieved, and meanwhile the problems of conicity and wall damage are avoided.

The invention provides a combined laser welding method and device.The method comprises the following steps that linear structured light is adopted to scan a welding seam area of a welding workpiece in the welding path direction, and morphological characteristics of the welding seam area are obtained; determining welding process parameters of the combined laser welding device according to the morphological characteristics and the material characteristics of the welding workpiece; the combined laser welding assembly is driven to move along the welding path, the welding seam area is welded, characteristic parameters of small laser holes in the welding seam area are monitored in real time, and in the continuous laser welding process, if the characteristic parameters exceed a preset range, pulse laser is switched to conduct welding on the welding seam area; and in the continuous laser welding process, if the characteristic parameters exceed the preset range, continuous laser is switched to conduct welding on the welding seam area. The problem that thermal stress is not uniform when different materials are welded can be effectively solved, the uniformity and strength of a welding area are guaranteed, high-precision welding of structural parts in complex shapes is achieved, and the welding precision and consistency are guaranteed.

The invention discloses double-laser machining equipment and method for tool machining. The double-laser machining equipment comprises a tool clamping mechanism and a gantry mounting frame which are arranged on a workbench. The cutter clamping mechanism drives the cutter to rotate; the infrared continuous laser processing head and the purple picosecond laser processing head are respectively mounted on the gantry mounting frame through a lifting mechanism, an infrared continuous laser beam emitted by the infrared continuous laser acts on the cutter through the infrared continuous laser processing head, and a purple picosecond laser beam emitted by the purple picosecond laser acts on the cutter through the purple picosecond laser processing head; the cutter clamping mechanism, the lifting mechanism, the infrared continuous laser, the infrared continuous laser machining head, the purple picosecond laser and the purple picosecond laser machining head are all electrically connected with the controller. The infrared continuous laser and the purple picosecond laser are integrated in the same equipment, the cutter is modified through double-laser cooperation, dynamic adjustment of laser parameters is achieved in combination with the lifting mechanism and the controller, the heat influence is effectively reduced, and the machining quality stability is improved.

The invention belongs to the technical field of wind tunnel measurement, and discloses a method and system for visualization of a large-scale high-enthalpy wind tunnel flow field structure. The method comprises the following steps: generating sheet light of which the width is greater than or equal to 300mm by using continuous laser of which the wavelength is 811.5 nm, and irradiating a wind tunnel flow field to excite naturally existing metastable state argon atoms and generate a fluorescence signal; collecting the fluorescence signal through a narrow-band filter with the central wavelength of 910nm and the bandwidth of less than or equal to 5nm in a direction perpendicular to a sheet light plane; performing synchronous scanning and displacement measurement on the sheet light and the signal acquisition device to obtain three-dimensional flow field data; and based on the three-dimensional flow field data, reconstructing a hypersonic speed wind tunnel flow field structure with the total enthalpy being greater than or equal to 10MJ / kg and the wind tunnel caliber being greater than or equal to 500mm. According to the invention, the problem that the prior art cannot satisfy the visualization of the fine flow field of the large-scale high-enthalpy wind tunnel is effectively solved, the tracing-free and wide-range measurement capability suitable for the extreme environment and the high model near wall surface is realized, and a new powerful tool is provided for the hypersonic velocity research.

The quantum current transformer based on the optical fiber isolation microwave transmission comprises a high-voltage primary side which comprises a magnetic shielding ring and an NV color center magnetic sensing probe module, and a magnetic sensing probe is arranged in the magnetic shielding ring; at the low-voltage secondary side, the microwave system is used for generating radio-frequency signals in a preset frequency range and transmitting the radio-frequency signals to the NV color center magnetic-sensing probe module, the laser system is used for generating continuous laser and transmitting the continuous laser to the NV color center magnetic-sensing probe module, and the microwave system and the laser system are used in cooperation to drive the NV color center to generate fluorescence signals representing the magnetic field intensity. A fluorescence signal is transmitted to the data processing system to calculate to-be-detected current information; wherein the microwave system is connected with the NV color center magnetic sensing probe module through an optical fiber, the microwave system modulates the radio frequency signal into an optical signal, transmits the optical signal to the NV color center magnetic sensing probe module, and restores the optical signal into the radio frequency signal in the NV color center magnetic sensing probe module to be received. According to the transformer, stable transmission of microwave signals under the high-low voltage isolation condition is achieved, the design is reasonable and exquisite, and the measurement precision is high.

The invention provides a low-cost ytterbium-doped Yb calcium silicate niobium aluminum gallium laser crystal and a preparation method and application thereof. According to the invention, Al < 3 + > is introduced to replace 50% Ga < 3 + >, Yb < 3 + > ions are doped, and the Yb: Ca3NbAl < x > Ga < 3-x > Si2O14 laser crystal (0lt; xlt; and 3) the raw material cost is greatly reduced, the growth period is shortened, the laser performance of the crystal is improved, the absorption cross section and the emission cross section of the crystal are increased, the half-peak width of absorption and emission peaks is broadened, the oblique efficiency and the light conversion efficiency of continuous laser output are further improved, the laser threshold value is reduced, and watt-level continuous laser output is obtained.

According to the corrosion cleaning method and corrosion cleaning system for the surface of the electrical equipment, continuous / pulse laser composite cleaning is conducted on the surface of the electrical equipment through semiconductor continuous laser and pulse laser, and different cleaning strategies are designed according to different corrosion layers of different materials; a set of high-efficiency, high-quality, low-damage and low-energy-consumption laser cleaning strategy is formed, multi-scene laser rust removal of electric power equipment is achieved, the maintenance efficiency and safety of electric power facilities are improved, on one hand, the problems that single-pulse laser energy attenuation is large, energy density is not enough, and long-distance electrified cleaning cannot be achieved can be solved, and on the other hand, the maintenance cost is reduced. On the other hand, the defect that the surface quality of a workpiece is poor due to pure continuous laser cleaning can be overcome, efficient and high-precision remote cleaning is achieved, in addition, semiconductor continuous laser is adopted, the needed equipment is small in size and mass, the light-weight design of the laser cleaning equipment is achieved, and the laser cleaning equipment is low in price and can be better accepted by users.

The present invention discloses a quantum random number generator chip and design method. The chip includes: an optical chip, a transimpedance amplifier chip, and a microcontroller chip connected in sequence, wherein: the optical chip includes a continuous laser, an optical beam splitter, a first optical attenuator, a second optical attenuator, a first photodetector, and a second photodetector; the microcontroller chip includes a first digital-to-analog converter, a second digital-to-analog converter, an analog-to-digital converter, and a processor; the transimpedance amplifier chip includes a transimpedance amplifier; wherein the optical chip, the transimpedance amplifier chip, and the microcontroller chip are packaged to obtain a quantum random number generator chip. The present invention packages the optical chip and the microcontroller chip into a single chip through a systematic packaging method, significantly reducing the size of the quantum random number system, greatly improving the stability of the system and structure, while reducing power consumption and cost, and expanding the scope and application scenarios.

The invention discloses a welding method for titanium alloy thick plates, and relates to the technical field of laser welding, and the method comprises the following steps: placing a plurality of titanium alloy thick plates to be welded on a workbench, carrying out backing welding on backing welding areas of the titanium alloy thick plates to be welded, and carrying out continuous laser processing through picosecond pulse laser, reciprocating motion is conducted in the molten pool and the forging area; after the backing welding process is finished, a first laser wire filling welding area and a second laser wire filling welding area between different titanium alloy thick plates to be welded are welded in a laser wire filling welding mode, in the welding process, picosecond pulse laser follows continuous laser machining, and the welding process is completed. And reciprocating motion is conducted in the molten pool and the forging area according to a preset motion trail, so that different titanium alloy thick plates to be welded are welded. The technical effect that uneven distribution of the structure performance of the welding joint is avoided is achieved.

The invention relates to the technical field of spectral measurement, in particular to a quantum correlation enhanced optical comb spectrum device and method, and the method comprises the steps: processing pump light and seed light to obtain idler frequency light and intrinsic light with quantum correlation; performing time domain matching adjustment on the idle frequency light, and reflecting the idle frequency light after the time domain matching adjustment to obtain a time-matched quantum correlation light beam; combining the intrinsic light and a continuous laser to obtain a first combined light; the mid-infrared light comb generates mid-infrared light carrying gas information after penetrating through the sample cell containing the gas to be detected; the light after the first beam combination and the mid-infrared light carrying the gas information are combined to obtain light after the second beam combination, frequency conversion processing is carried out, and then a near-infrared light comb is output; and processing the quantum correlation light beam and the near-infrared light comb which are matched in time, and outputting a double-light comb signal. Through combination of a quantum correlation mechanism and a frequency conversion technology, the intermediate infrared spectrum detection signal-to-noise ratio is remarkably improved, and high-sensitivity and high-speed parallel quantum enhanced spectrum is realized.

The invention relates to the technical field of biomedical detection, in particular to an exosome particle size distribution detection processing method and system which are used for accurately measuring and analyzing the size distribution characteristics of exosomes in a biological sample. The method comprises the following steps: firstly, extracting and marking an exosome from a cell culture supernatant by using an exosome extraction kit; arranging a capture probe in a light scattering detection system, wherein the system comprises a microscope lens and a three-color camera which are connected with a calculation module; an exosome image is transmitted to a three-color camera through a microscope lens, and detection is carried out by utilizing the fluorescence wavelength and a light scattering signal of a super-continuous laser; in the continuous change of the laser emission angle, calculating the particle size distribution of the exosome according to an optical signal; according to the method, the detection precision and accuracy are improved, the improvement from two-dimensional information to three-dimensional information is realized, the characterization problem of the non-spherical exosome is solved, and a more accurate and comprehensive tool is provided for exosome research.

The invention relates to the technical field of laser splitting, and provides a dual-laser synchronous coaxial modified stripping device which comprises a mobile platform, a first pulse laser system, a second pulse laser system and a pulse delay regulation and control system, the moving platform can move the to-be-stripped part along a plurality of different directions; the first pulse laser system emits ultrashort pulse laser to the to-be-stripped part through a first light path, so that an initial modified layer is formed in the to-be-stripped part; the second pulse laser system synchronously emits continuous laser to the to-be-stripped part through a second light path, so that the initial modified layer is heated to form a cracked complete modified layer; the pulse delay regulation and control system is arranged in the first light path and comprises a plurality of regulation and control parts which are arranged in the first light path at intervals in the same straight line direction; and the plurality of regulation and control parts are used for enabling the ultrashort pulse laser irradiated in the pulse delay regulation and control system to form at least two different optical path differences, and mutually interfere in the pulse delay regulation and control system to form pulse delay.

The invention provides a P-SCH layer, a CW laser epitaxial structure and a preparation method of the P-SCH layer and the CW laser epitaxial structure, and belongs to the field of semiconductors. The invention provides a P-SCH layer which is of a multi-layer structure, the number of layers of the multi-layer structure is 2n, n is larger than or equal to 2, and the emission wavelength is gradually increased from the first layer to the 2n layer; the difference between the emission wavelength of the (n + 1) th layer and the emission wavelength of the nth layer is 100-120nm, and the difference between the emission wavelengths of the other adjacent layers is 10-20nm. According to the invention, the stepped structure with small emission wavelength span at two ends and large middle span between layers ensures the electron leakage rate and the hole injection rate to a great extent, thereby controlling the increase rate of the photon density along with current injection, and improving the temperature stability of the device.

The invention discloses a wavelength division multiplexing phi-OTDR and BOTDR fusion demodulation method, system and device and a storage medium, and relates to the technical field of distributed optical fiber sensing, and the method comprises the steps: employing a double independent narrow linewidth laser to output continuous laser, enabling each path to be divided into two beams through a coupler, enabling one beam to be subjected to pulse modulation, and enabling the other beam to be used as local oscillation light; pulse light is modulated into frequency-shift pulse light through an acousto-optic modulator, and the frequency-shift pulse light is injected into a sensing optical fiber after being combined by an optical combiner. And the backscattered light is separated by the optical wave separator according to the wavelength. Rayleigh signals are subjected to coherent receiving and orthogonal demodulation to obtain light intensity; brillouin signal amplification, frequency mixing and the like are performed to extract frequency shift. In combination with light intensity and frequency shift, temperature strain is decoupled, and vibration information is demodulated; according to the invention, the measurement precision is improved, and the line potential risk can be found in time; efficient signal isolation and transmission and temperature strain decoupling measurement are achieved, and pipeline safety is guaranteed; the structure is simple and easy to expand, and long-distance, low-cost and high-precision monitoring and timely disaster early warning can be realized.

The invention discloses a high-precision temperature control system of semiconductor chip annealing equipment, and relates to the technical field of semiconductor manufacturing, and the system comprises annealing equipment and temperature detection equipment; the annealing equipment comprises a continuous wave fiber laser and a pulse laser; the temperature detection equipment comprises a synchronous control module and a Raman spectrum module; the Raman spectrum module comprises an acquisition module, a preprocessing module and an analysis module. The annealing equipment adopts a continuous wave fiber laser (high power) and a pulse laser (low power) to cooperatively work and is respectively responsible for preheating and dopant activation. And the temperature detection equipment synchronously acquires Raman scattering light, calculates a temperature field after denoising and separation, and feeds back and controls the continuous laser power. Thermal stress is reduced through continuous laser preheating, a doping agent is accurately activated through pulse laser, and annealing uniformity is improved. The Raman spectrum realizes temperature detection of micron-order spatial resolution, the synchronous control module dynamically adjusts laser power, and the temperature control precision is improved.

The invention discloses a method for cutting silicon nitride ceramic based on laser. The invention provides a method for cutting silicon nitride ceramic based on laser. The method comprises the steps that a silicon nitride ceramic mold to be cut is fixed to a workbench of a laser cutting device through a clamp; setting laser processing parameters; coating an absorbent on a pre-cutting area of the silicon nitride ceramic; according to the cutting path and the laser processing parameters, a laser of a laser cutting device is used for cutting the silicon nitride ceramic, and continuous laser is used for moving and cutting on the surface of the silicon nitride ceramic along the set path; and auxiliary gas coaxial with the light beam is used for blowing away molten substances, and a cooling effect is achieved, so that continuous kerfs are formed on the surface of the silicon nitride ceramic, the laser absorptivity of the ceramic can be increased, and the processing efficiency and quality of the silicon nitride ceramic are improved.