136 results about "Laser modulation" patented technology

A wide-field dynamic magnetic imaging device and method. The wide-field dynamic magnetic imaging device comprises: a probe assembly (1), comprising a diamond (101) containing NV centers; a microwave magnetic field assembly (2) configured to generate a uniform microwave field and a uniform bias magnetic field in the vicinity of the diamond (101), so as to regulate the spin energy level of the diamond (101) and the quantum state evolution process; a laser modulation assembly (3) configured to output an initial uniform pulsed laser to excite the diamond (101) to emit fluorescence; a fringe light modulation assembly (4) configured to modulate the initial uniform pulsed laser to output a fringe pulsed laser, causing the fluorescence emitted by the diamond (101) to be fringe fluorescence, or to modulate the fluorescence emitted by the diamond (101) into fringe fluorescence; a fluorescence detection assembly (5) configured to perform spatial imaging on the fringe fluorescence to obtain magnetic field information of a sample under test (7), thereby obtaining an initial magnetic image of said sample (7); and a data processing assembly (6) configured to perform Fourier transform and inverse Fourier transform on the initial magnetic image to obtain a first magnetic image.

The invention belongs to the technical field of flow field optical measurement, and particularly relates to a high-enthalpy plasma gas temperature measurement method, system and device based on an absorption spectrum. Generating a composite modulation signal through a high-frequency sine wave and a low-frequency sawtooth wave, and enabling incident light to pass through a flow field measurement area in parallel through laser modulation and beam shaping; the detector receives the transmission light and converts the transmission light into an electric signal containing harmonic information, the signal acquisition device is used for performing signal acquisition, the phase-locked demodulation algorithm is used for extracting second harmonic, and the temperature is inversely deduced by combining the double-spectral-line temperature measurement method and the Fourier coefficient amplitude ratio of the second harmonic with the HITRAN database. The system comprises a signal driving module, a laser emission module, a detection acquisition module and a temperature measurement module. The device is composed of a signal generator, an in-phase adder and the like, and a laser is matched with a driving power supply to guarantee stable work. According to the scheme, aiming at the problems of weak signal absorption and insufficient signal-to-noise ratio under complex working conditions, the measurement accuracy and reliability are improved by composite modulation, harmonic extraction and a bispectral line algorithm, and an effective means is provided for research on thermal characteristics of the high-enthalpy plasma.

The invention discloses a high-efficiency low-loss preparation method of a single crystal silicon carbide wafer. The method comprises the following steps: A, grinding the surface of a single crystal silicon carbide ingot; b, the ultrafast pulse laser is modulated into N light spots, the N light spots are focused in the crystal ingot and distributed in the axial direction of the crystal ingot according to preset depth positions, and all the light spots are parallel to the horizontal direction; all the light spots are scanned at the same time, the scanning surface formed by the same light spot covers the cross section of the single crystal silicon carbide crystal ingot in the horizontal direction, and N laser modified layers are formed after scanning; c, carrying out stress-induced separation on the single crystal silicon carbide crystal ingot in the step B; and D, grinding the cutting surface of the single crystal silicon carbide wafer. According to the high-efficiency and low-loss preparation method of the single-crystal silicon carbide wafer, the preparation efficiency of the silicon carbide wafer is improved, meanwhile, the material loss of the single-crystal silicon carbide ingot is reduced, and the yield of the single-crystal silicon carbide ingot is improved.

The invention relates to the technical field of optical precision measurement, in particular to an ultra-high time resolution camera time characteristic detection device and method, and the device comprises a laser source which is used for generating pulse laser; the polarization modulation element is arranged on an emergent light path of the laser source and is used for modulating the pulse laser into circularly polarized light; the spectroscope is arranged on an emergent light path of the polarization modulation element and is used for decomposing the circularly polarized light into a first linearly polarized light beam and a second linearly polarized light beam; the first optical path unit is used for guiding the first linearly polarized light beam to the cylindrical optical element along a fixed optical path; the second optical path unit is used for adjusting the optical path of the second linearly polarized light beam and guiding the second linearly polarized light beam to the cylindrical optical element; and the cylindrical optical element is used for receiving the first linearly polarized light beam and the second linearly polarized light beam and respectively projecting the first linearly polarized light beam and the second linearly polarized light beam to an imaging surface of a camera to be detected to form two spatially separated light spots. The objective of the invention is to improve camera time characteristic calibration precision and efficiency.

This invention relates to a Bragg light generation system and method suitable for Bragg-type atomic interferometers. The system includes: a laser for generating a first laser beam with a frequency in a preset atomic absorption peak band; an optical circulator for propagating the first laser beam to a cascaded acousto-optic modulator and receiving two third laser beams returned from the cascaded acousto-optic modulator; a cascaded acousto-optic modulator for diffracting the first laser beam into two second laser beams with opposite propagation directions through Bragg diffraction of two acousto-optic crystals; an optical assembly for performing secondary diffraction on the two second laser beams and reflecting the two mutually perpendicular second laser beams to the cascaded acousto-optic modulator; and an output module for splitting and sampling the two third laser beams and modulating the sampled third laser beams into Bragg laser beams in the target frequency band. This invention reduces the path separation of the two Bragg laser beams by using a quasi-common optical path, thereby reducing phase noise and improving measurement accuracy.

The invention discloses a femtosecond pulse laser modulation-based GaN-based micro light-emitting diode test system, which comprises a femtosecond pulse laser excitation module, a first detection light path, a to-be-tested GaN-based micro light-emitting diode, a photovoltage detection and bias control module, a photoluminescence detection module and a control module, the control module is configured to control the excitation power and the external bias voltage of the femtosecond pulse laser excitation module, and synchronously collect a photoluminescence spectrum signal and a photovoltage signal; according to the excitation power, the external bias voltage, the photoluminescence spectrum signal and the photovoltage signal, the competition relation between carrier drift extraction and local radiation recombination under different bias electric field conditions is obtained, and therefore an experimental basis is provided for structural design and working bias optimization of the GaN-based micro light-emitting diode device to be tested.

The invention discloses Ge-Sn-Se-S acousto-optic chalcogenide glass, the chemical composition formula of the Ge-Sn-Se-S acousto-optic chalcogenide glass is Ge20SnxSe80-x-ySy, x and y respectively represent molar fractions of Sn and S, x is equal to 5-12.5, y is equal to 0-25, and a basic network unit of a glass frame of the Ge-Sn-Se acousto-optic chalcogenide glass is of a stable tetrahedral structure with Ge or Sn as the center. The acousto-optic chalcogenide glass is large in composition regulation and control range, easy to form, non-toxic, environment-friendly, green and quaternary chalcogenide glass system, high in linearity and refractive index and high in acousto-optic performance, the acousto-optic quality factor M2 under the wavelength of 1550 nm is 211.8 * 10 <-18 > s < 3 > / g to 348.9 * 10 <-18 > s < 3 > / g, the ultrasonic attenuation alpha under the ultrasonic frequency of 10 MHz is 0.72 dB / cm to 4.89 dB / cm, the laser damage threshold value is 2.94 J / cm < 2 > to 15.54 J / cm < 2 >, and the acousto-optic chalcogenide glass can be used for preparing the acousto-optic chalcogenide glass. The material has the potential of being applied to acousto-optic devices for high-power laser modulation, and can be widely applied to the acousto-optic field as an acousto-optic medium.

The invention discloses a sine frequency modulation harmonic error compensation method based on Bessel function modulation characteristics, and relates to the technical field of sine frequency modulation nonlinear parameter compensation and high-precision measurement of target absolute distance based on multi-wavelength interference. The problem that the constant phase demodulation precision is insufficient due to the fact that carrier harmonic waves, accompanying amplitude modulation and modulation depth errors cannot be effectively suppressed due to laser modulation nonlinearity in existing sine frequency modulation distance measurement is solved. According to the method, after sine frequency modulation interference signals are collected, high-pass filtering is carried out to remove low-frequency components, Hilbert transform is carried out to remove envelope suppression associated amplitude modulation, window function frequency mixing is carried out to extract modulation depth, a matched carrier containing second harmonics is constructed, and frequency modulation harmonic parameter optimization is achieved through baseband amplitude maximization. And finally, carrying out orthogonal demodulation on the compensated interference signal to obtain a high-precision constant phase. The method is suitable for high-precision multi-wavelength interference ranging, precision displacement measurement and optical metering systems.

The invention belongs to the technical field of fluorescence spectrum collection, and particularly relates to a quasi-three-dimensional fluorescence spectrum collection method and spectrograph based on a software phase locking technology, and the method comprises the following steps: respectively modulating coprime modulation frequencies of a plurality of laser light sources with different wavelengths, and synchronously exciting the laser light sources to the surface of a sample; a fluorescence signal generated on the surface of the sample is received and processed by a linear array CCD detector to obtain a multi-wavelength spectral signal simultaneously containing background light, scattered light and fluorescence components; inputting the multi-wavelength spectral signal into a software phase-locked amplification system, introducing a Costas ring to the software phase-locked amplification system for real-time tracking and correction, and generating a synchronous reference signal consistent with the laser modulation frequency; inputting the synchronous reference signal into a software lock-in amplifier, and extracting a plurality of pure fluorescence spectrum components excited by specific-frequency laser; and synthesizing the plurality of pure fluorescence spectrum components to finally form a quasi-three-dimensional fluorescence spectrum.

The invention provides a self-wave-locking method and system based on laser photoacoustic spectrometry gas detection, and relates to the technical field of optical gas sensing, by fusing multi-physical field sensing data such as photoacoustic signals, sound field distribution, thermal deformation and the like, a first state vector representing the actual performance of a current system is calculated in real time, and a second state vector representing the actual performance of the current system is calculated in real time; a multi-objective optimization function is used for simultaneously optimizing a signal-to-noise ratio, linearity and energy consumption control to serve as a criterion, a cooperative control instruction is generated in a rolling mode, excitation light modulation parameters and cavity acoustic mode parameters are accurately adjusted, double dynamic tracking and locking of laser modulation frequency and cavity acoustic resonance frequency are achieved, and when external conditions change, the frequency of the cavity acoustic resonance frequency can be dynamically tracked and locked. According to the method, the detection sensitivity and the signal stability which are close to theoretical limits are automatically and continuously kept all the time, the calculated system nonlinearity index is used as an internal criterion, a concentration inversion mode is intelligently switched to carry out gas concentration value calculation, and seamless, continuous and wide dynamic range measurement from ppb level to percentage level is realized.

An optical device includes a generator, a light emitter, a modulator, an optical amplifier, a current source, a storage, and a controller. The generator generates an electric signal of a multilevel amplitude modulation method. The light emitter emits laser light. The modulator modulates the laser light using the electric signal and outputs an optical signal. The optical amplifier optically amplifies the modulated optical signal according to a drive current. The current source adjusts the drive current to be supplied to the optical amplifier. The storage previously stores an information with respect to input-output characteristics of the optical signal in the optical amplifier relative to drive current value of the drive current. The controller acquires, from the storage, the input-output characteristics corresponding to the drive current value of the drive current supplied to the optical amplifier and controls the electric signal based on the acquired input-output characteristics.

The invention discloses a mid-infrared laser based on three-device on-chip integration and a preparation method thereof, relates to the crossing field of a semiconductor laser technology and an optical communication technology, and solves the problem that the existing quantum cascade laser QCL technology cannot give consideration to both high modulation rate and high power. An intermediate infrared laser comprises a QCL unit, an EAM unit and an SOA unit which are sequentially arranged on a substrate. The substrate comprises a semi-insulating InP (Indium Phosphate); the QCL unit, the EAM unit and the SOA unit share the same ridge-shaped waveguide structure and grow through epitaxy butt joint. The method provided by the invention is suitable for a mid-infrared band space communication scene with high requirements on the laser modulation rate, the output power and the single-mode stability.

The invention provides a quantum communication teaching experiment system and method. The quantum communication teaching experiment system comprises an Alice sending end and a Bob receiving end, the Alice sending end is provided with a first laser light source and a first half-wave plate, the first laser light source can emit linearly polarized light at intervals, and the linearly polarized light is randomly modulated into an emission polarization state through the first half-wave plate and is emitted to the Bob receiving end; the Bob receiving end is provided with a second half-wave plate, a first polarization beam splitter, a first detector, a second detector and a first postprocessor, and the first postprocessor is in communication connection with the first detector and the second detector; the linearly polarized light emitted from the Alice sending end is randomly measured and modulated by the second half-wave plate and then is emitted to the first polarization beam splitter, and the first detector is used for detecting the linearly polarized light reflected and emitted by the first polarization beam splitter. The second detector is used for detecting the linearly polarized light transmitted and emitted by the first polarization beam splitter, and the first postprocessor is used for comparing the photoelectric conversion voltage of the first detector and the photoelectric conversion voltage of the second detector so as to control the corresponding indicator lamp to be turned on. The BB84 quantum communication protocol is simulated, and experimenters can operate laser modulation and observe experimental phenomena, so that the BB84 quantum communication protocol can be fully understood.

The application discloses a kind of adjustable distributed optical fiber sensing performance promotion device, sensing system and method, device includes: narrow linewidth laser, acoustooptic modulator, first signal generator and frequency shift ring;Narrow linewidth laser is configured to output narrow linewidth laser to acoustooptic modulator;First signal generator is configured to generate pulse function signal, function signal controls acoustooptic modulator, and single-frequency laser is modulated into pulsed light;Acoustooptic modulator is configured to modulate single-frequency laser into corresponding pulsed light in acoustooptic modulator according to the pulse function signal generated by first signal generator;Frequency shift ring is configured to multiple cyclic frequency shifts of pulsed light into it, and generate broadband multi-frequency light output.The device generates MHz-level pulsed light by acoustooptic modulator modulation, and generates GHz-level broadband multi-frequency light by multiple cyclic frequency shifts of frequency shift ring, which is applied to sensing system, and the response bandwidth of sensing system can be improved, and the flexibility of sensing test is improved.

The application relates to the technical field of spectral analysis, and discloses a fluorescence spectral analysis device and method based on a solid-state electron spin ensemble, wherein the spectral analysis device comprises a laser modulation unit, a confocal unit and a fluorescence processing unit; the laser modulation unit comprises a laser, a Griesinger-Taylor prism, an acousto-optic modulator, a beam expander, a collimating lens, a spatial light modulator, a spatial filter and a half-wave plate which are sequentially arranged; the confocal unit comprises a dichroic mirror, a focusing lens, a diamond and a microwave antenna which are sequentially arranged; the diamond has a solid-state electron spin NV color center; and the fluorescence processing unit comprises a filter group, a sleeve lens, a lens, a linear polarizer, a Bertin lens and a camera which are sequentially arranged. The application distinguishes the fluorescence generated by different axial NV color centers from the fluorescence level, and provides a thought and method for the miniaturization and bias magnetic field removal of a quantum detection device of the NV color center.

The application relates to a laser-assisted micro-anode local area electro-deposition additive manufacturing device and method, and belongs to the technical field of additive manufacturing and local area electro-deposition. A support is fixed on a base, a screw rod device is installed above the support and is connected with an xy-axis moving device, a z-axis moving device is installed on the xy-axis moving device, a micro-anode device is connected to the z-axis moving device, a printing chamber is installed on an adjustable support and can move along the z-axis, a light modulation device is installed on an adjustable frame and can move along the z-axis, and the adjustable frame and a laser are fixed on the base. The method combines laser modulation technology and electrochemical deposition technology, uses laser modulation to generate patterned light to generate a virtual electrode for local area electro-deposition, greatly improves printing resolution and part performance, further improves printing precision, avoids the generation of thermal residual stress in the metal part, the performance of the part is more superior, and the method is used for micron-level metal part manufacturing.

The invention discloses a delay measurement system and method for a microwave over fiber transmission link, and belongs to the technical field of microwave photonics. The modulator is used for modulating the radio-frequency signal generated by the radio-frequency signal generator to an optical carrier and generating modulated light containing + / -1-order sidebands; the radio frequency signal is a dual-tone signal with the frequency range of 30 GHz to 70 GHz; the frequency shift unit is used for performing frequency shift on the modulated optical signal; and the dual-optical mixing unit is used for mixing the return signal and the reference signal and converting the phase shift direct detection of the high-frequency signal into the relative phase shift detection of the intermediate-frequency signal. A dual-tone signal is modulated into a 1550nm optical carrier, + / -1-order sidebands are separated through a dual-optical mixing structure, intermediate frequency signals of the + / -1-order sidebands are detected through a balanced photoelectric detector, and phases are detected, so that link transmission delay is calculated. The problem of phase ambiguity of high-frequency signals during large-range measurement is solved, and large-range absolute delay measurement is realized.

The invention discloses an SPR phase imaging system based on a four-polarization filtering array, and the system comprises an incident light path which is used for generating area array laser; the SPR module is used for receiving the area array laser and carrying out SPR sensing to obtain an area array laser modulation result related to a to-be-detected substance; and the imaging light path is used for carrying out amplification and filtering modulation on the area array laser modulation result so as to carry out imaging on a four-polarization array, and carrying out matched filtering and double-differential phase resolving on a four-polarization image so as to obtain an imaging result. According to the invention, through polarization virtual image generation and cross-channel block matching, and in combination with four-dimensional collaborative filtering, the noise suppression efficiency is improved; and through double differential phase resolving, the dynamic range is expanded to 0.06 RIU, and the resolution ratio is superior to that of the RIU. The invention solves the problem of mutual restriction of dynamic range and resolution in the traditional SPR technology, and is suitable for high-sensitivity biomolecule interaction detection.

The invention discloses a laser frequency stabilization electric control system based on a modulation transfer spectrum, and the system is constructed based on a ZYNQ7030 heterogeneous SoC platform, and integrates laser modulation, signal collection, error extraction, feedback control and man-machine interaction functions. Comprising a sinusoidal modulation chain driven by a high-speed DAC and an electro-optical modulator which are used for realizing laser frequency modulation; the MTS signal acquisition link consists of a photoelectric detector, a low-noise amplifier and a high-speed analog-to-digital converter; feedback control is carried out on the frequency of the laser through the precise digital-to-analog converter and the current source circuit. Meanwhile, the system integrates an air cavity temperature control module, a multi-channel communication interface and a man-machine interaction module, and frequency stabilization and system management are achieved. According to the invention, high-precision and high-stability laser frequency locking based on the rubidium atom absorption spectrum can be realized without depending on an external frequency standard, and reliable frequency reference is provided for applications such as high-precision atom physical experiments, quantum sensing, spectral measurement and the like.

The application belongs to the technical field of laser application, and discloses a multi-wavelength laser frequency multiplication device and a multi-wavelength spatial laser modulation device. The multi-wavelength laser frequency multiplication device comprises a base A and one or more laser frequency multiplication units. Two rows of first mounting grooves are arranged on the two sides of the base A in parallel along the length direction of the base A. Each row of the first mounting grooves comprises two or more coaxially arranged clamping grooves A, and the clamping grooves A on the two rows of the first mounting grooves are symmetrically arranged. The laser frequency multiplication unit is mounted in the symmetrically arranged clamping grooves A of the two rows of the first mounting grooves. Each laser frequency multiplication unit corresponds to laser of one wavelength, and performs frequency multiplication processing on the laser of the corresponding wavelength. The multi-wavelength spatial laser modulation device comprises a fundamental frequency laser, a selective frequency multiplication mechanism provided with the multi-wavelength laser frequency multiplication device, and a laser shaping and amplifying mechanism. The application has the characteristics of simple structure and strong expansibility, and is suitable for use in a spatial laser application system to synchronously modulate the multi-wavelength laser frequency, waveform and power.

Spectroscopic sensor for characterizing the absorption or determining the concentration of solid materials or liquid samples based on the photoacoustic effect, comprising - a device into which the liquid or solid sample to be analyzed is inserted or placed, - at least one laser in modulation mode to excite the material-specific molecules, - at least one sound transducer for detecting the sound pressure wave, - a device for detecting and processing the photoacoustic signal, characterized in that at least one sound transducer in the form of a quartz tuning fork (QTF) is used, the resonance frequency of which corresponds to the laser modulation frequency, that an acoustic resonator of a certain geometry, which is placed on the sample and has the same resonance frequency as the QTF, is used, that the laser modulation frequency corresponds to the resonance frequency of the resonator, and that the gas which fills the resonator shows as little or no absorption as possible in the wavelength range of the laser.

A laser system includes a first laser outputting first laser light, an optical intensity changer outputting first pulse laser light, a modulator widening spectral linewidth of the first laser light or the first pulse laser light, an optical fiber amplifier amplifying the first pulse laser light and outputting second pulse laser light, a second laser outputting second laser light, an optical parametric amplifier amplifying the second laser light and outputting third pulse laser light, a wavelength converter outputting fourth pulse laser light using the second and third pulse laser light, an amplification section amplifying the fourth pulse laser light and outputting fifth pulse laser light, and a processor controlling a modulation signal such that the fifth pulse laser light having target spectral linewidth is generated, and controlling the center wavelength of the second laser light such that the fifth pulse laser light having a target center wavelength is generated.

The utility model discloses an art knife laser quenching device which comprises a working table, a sealing box, a sapphire lens window and an art knife sample piece, a driving assembly capable of driving the art knife sample piece to move is arranged in the sealing box, and a protection support is further arranged at the top of the working table. A laser capable of being movably adjusted is arranged on the protection support, the laser is provided with two laser heads, and one laser can control the two laser heads to synchronously quench the two sides of an art knife sample piece at the same time. According to the art knife laser quenching device, the laser device is provided with the two laser heads, and the two sides of an art knife sample piece can be synchronously quenched at the same time; through cooperation of the laser modulator and the beam shaper, it is ensured that energy is evenly distributed in the quenching process, nitrogen is introduced into the sealing box to serve as shielding gas, oxidation of the tool in the quenching process is effectively prevented, and meanwhile cold nitrogen is used for conducting cooling and nitriding treatment on the tool in the quenching process.

This invention provides a laser system and its control method and device. The laser system includes a laser, a laser modulator for modulating the initial laser output from the laser, a cooling device for cooling the laser modulator using a cooling fluid, and a temperature sensor for detecting the temperature of the cooling fluid. In the control method, by acquiring the temperature difference of the cooling fluid at the current moment, determining the change in temperature difference of the cooling fluid at the current moment, and adjusting the excitation energy input to the laser based on the change in temperature difference of the cooling fluid at the current moment, the power of the laser output after modulation by the laser modulator can reach the target power. The solution of this invention ensures the timeliness and accuracy of the adjustment of the excitation energy.

The invention provides a laser stabilizing device and a laser. The laser stabilizing device comprises an actuator, a frequency controller, a power controller and a driving modulator. The actuator comprises a laser modulation module which is used for adjusting the first laser according to the control signal and outputting the second laser. The frequency controller comprises a frequency error generation module which is used for comparing the frequency of the second laser with the reference frequency and generating a frequency error adjusting signal. The power controller comprises a power error generation module which is used for comparing the power of the second laser with the reference power and generating a power error adjusting signal. The driving modulator comprises a frequency control module and a power control module. The frequency control module is used for generating a radio frequency signal and adjusting the frequency of the radio frequency signal according to a frequency error adjusting signal. The power control module is used for receiving the radio frequency signal output by the frequency control module and adjusting the amplitude of the radio frequency signal according to the power error adjusting signal. And the radio frequency signal is used as a control signal input into the laser modulation module.

A method, system, and apparatus for synchronizing laser dither and correlator clocks to improve dynamic light scattering is disclosed. An example laser dither and correlator synchronizing system includes a laser driver configured to output a laser. The example laser dither and correlator synchronizing system further includes a correlator having an internal clock. The example laser dither and correlator synchronizing system further includes a waveform generator configured to receive a clock signal from the internal clock of the correlator, receive a dither signal from a controller, and output a laser modulation signal to the laser driver based on the dither signal and the clock signal.

The invention discloses a test system suitable for the performance of an acousto-optic modulator, and the system comprises a light source directivity test unit, a zoom lens group, a pre-diffraction power monitoring unit, a response time test unit, a post-diffraction directivity test unit, a diffraction efficiency test unit, and an imaging efficiency test unit. The acousto-optic modulator to be tested is arranged between the pre-diffraction power monitoring unit and the response time testing unit, the acousto-optic modulator to be tested is in control connection with the stability control unit, and an isolator is arranged between the light source directivity testing unit and the zoom lens group. According to the method, the optimal use performance of the acousto-optic modulator in different laser application fields can be achieved, meanwhile, the method is also suitable for application of the optical fiber type acousto-optic modulator, and the method can be used for design of all wavebands, all powers and all laser modulation systems.

The present application belongs to the field of laser intermittent machining method, and particularly relates to a water guide laser intermittent machining method for three-dimensional complex structure, comprising the following steps: S1, rotating the super-hydrophobic baffle to periodically deflect at a rotation speed of 10-200 rpm, and switching the water flow on and off through an angle change of 0-15 degrees; S2, collecting water flow impact pressure data in real time by a pressure sensor to generate a dynamic electrical signal; S3, sending a pulse on-off instruction to a laser modulation module based on the amplitude mutation characteristics of the electrical signal; S4, adjusting the feeding speed and laser emission frequency according to the curvature radius value of the machining path by a multi-axis linkage mechanism. Through the dynamic water guide of the rotating baffle and the laser-motion collaborative control, the water flow on and off does not need to restart the high-pressure system, and the machining efficiency is doubled; the pressure sensor triggers the laser pulse in real time, and eliminates the invalid energy dissipation; the multi-axis linkage adapts to the curvature change, and the machining precision of the complex structure reaches the micron level.

The application relates to the technical field of magnetic field measurement, in particular to a double-frequency resonance locking system of an NMOR atomic magnetometer based on FPGA, which comprises an FPGA, a laser modulation driving unit and a signal acquisition and processing unit, a homologous synchronous reference signal source, a first demodulation branch and a second demodulation branch are arranged in the FPGA, signals corresponding to a single Larmor frequency and double Larmor frequency are synchronously demodulated respectively to obtain corresponding in-phase signals and quadrature signals. The FPGA determines corresponding weight coefficients according to the output signals of the two demodulation branches, fuses corresponding frequency correction amounts and obtains a frequency control amount to adjust the laser modulation frequency. The system is also provided with a frequency sweeping and peak searching logic and a host computer parameter configuration module. The application is used for realizing that there is always a feedback signal with sufficient signal-to-noise ratio in the whole space range, so that the measurement blind area of the single-frequency NMOR magnetometer is eliminated.

The application relates to an indium-based selenite second-order nonlinear optical crystal material and preparation and application thereof, the chemical formula of the crystal material is In(HSeO3)3.3H2O, the molecular weight is 552.77, the crystal material belongs to the trigonal system, the space group is R3c (No. 161), the cell parameter is alpha = beta = 90 DEG, gamma = 120 DEG, and Z = 6. The powder frequency doubling effect of the second-order nonlinear optical crystal In(HSeO3)3.3H2O under 1064nm laser irradiation is about 0.1 times that of a KH2PO4 crystal, and phase matching can be realized. In addition, the crystal material has a short ultraviolet absorption cutoff edge (216nm), and has important application value in the fields of laser modulation, radio equipment, satellite communication and the like.