1317 results about "Line width" patented technology

The invention relates to the technical field of semiconductor lasers, in particular to a laser based on a bimetallic Bragg grating and a top surface HR reflecting film, which comprises a gain chip, a first high-reflection HR film is plated on the left end surface of the gain chip, and a first anti-reflection AR film is plated on the right end surface of the gain chip. A metal Bragg grating waveguide is arranged on the right side of the gain chip, the right end face of the gain chip and the left end face of the metal Bragg grating waveguide are aligned and attached to form an outer cavity structure, and the left end face of the metal Bragg grating waveguide is plated with a second anti-reflection AR film. The right end face of the metal Bragg grating waveguide is plated with a third anti-reflection AR film. Performance test is carried out on the laser provided by the invention, and test results show that the line width is 0.6 kHz, the SMSR is 63dB, and the threshold current is 22mA, thereby verifying the effectiveness of the laser provided by the invention.

The invention relates to the technical field of laser, in particular to a dual-wavelength narrow-linewidth laser output device and method.The dual-wavelength narrow-linewidth laser output device comprises a semiconductor laser unit emitting linearly polarized light beams, and a light beam conversion lens is used for achieving conversion of semiconductor laser fast-axis light beams and semiconductor laser slow-axis light beams; the light beam conversion lens is used for collimating and compressing a semiconductor laser fast axis divergence angle, and the slow axis collimating lens is used for collimating and compressing a semiconductor laser slow axis divergence angle; the linearly polarized light beam is divided into a first light beam and a second light beam through the rectangular prism; the first light beam sequentially passes through a first volume Bragg grating, a first reflector, a half-wave plate and a polarization beam combiner; the second light beam sequentially passes through a second volume Bragg grating, a second reflector and a polarization beam combiner; the dual-wavelength narrow-linewidth semiconductor laser can solve the problems of precise regulation and control and power amplification of the central wavelength of the dual-wavelength narrow-linewidth semiconductor laser, has power expansibility, and realizes improvement of laser power by stacking a plurality of laser units in the vertical direction.

The invention provides an OFDR sensing system and method for rapidly positioning strain based on a time domain difference algorithm, and relates to the technical field of optical fiber sensing. The OFDR sensing system comprises a narrow linewidth tunable laser light source, a first optical fiber coupler, a main interferometer, an auxiliary interferometer and a data acquisition and signal processing module; laser emitted by the narrow linewidth tunable laser light source is divided into two paths through the first optical fiber coupler, one path of light enters the main interferometer, and the other path of light enters the auxiliary interferometer; the main interferometer and the auxiliary interferometer respectively output a main interferometer optical signal and an auxiliary interferometer optical signal to the data acquisition and signal processing module; the data acquisition and signal processing module is used for performing nonlinear compensation on the optical signal of the main interferometer by using the optical signal of the auxiliary interferometer, and performing cross-correlation operation on a reference optical signal of the main interferometer and a measurement optical signal of the main interferometer which are based on the strain-free state and the strain state of the sensing optical fiber and are subjected to nonlinear compensation; and obtaining the strain position and the strain value of the sensing optical fiber.

The invention relates to the technical field of semiconductor lasers, in particular to a laser based on a bimetallic Bragg grating and a top SiO2 waveguide layer, which comprises a gain chip, the left end face of the gain chip is plated with a first high-reflection HR film, and the right end face of the gain chip is plated with a first anti-reflection AR film; a metal Bragg grating waveguide is arranged on the right side of the gain chip, the right end face of the gain chip and the left end face of the metal Bragg grating waveguide are aligned and attached to form an outer cavity structure, and the left end face of the metal Bragg grating waveguide is plated with a second anti-reflection AR film. The right end face of the metal Bragg grating waveguide is plated with a third anti-reflection AR film. According to the invention, a temperature change test is carried out, and the wavelength drift is controlled to be + / -0.002 nm in a range of-40 DEG C to 85 DEG C; performance test results show that the line width is 0.6 kHz, the SMSR is 65 dB, and the threshold current is 22 mA.

The invention discloses a signal-to-noise ratio improvement method based on a multi-core optical fiber dual-channel distributed acoustic sensing system, and the method comprises the steps: carrying out the light splitting of light emitted by a narrow linewidth laser through a first coupler C1, enabling one path of light to generate a pulse signal through an acoustic optical modulator (AOM), enabling the other path of light to pass through a second coupler C2, and enabling the other path of light to pass through a second coupler C1; the pulse light is divided into two beams of transmission light, the two beams of transmission light are injected into a connected sensing optical fiber through two groups of erbium-doped optical fiber amplifiers (EDFA), two groups of filters, two groups of circulators and a fan-in coupler Fan-in Coupler, and the pulse light is subjected to backward Rayleigh scattering in the sensing optical fiber; based on a dual-channel DAS system, a multi-core optical fiber is used as a sensing optical fiber, three cores and four cores of the multi-core optical fiber are connected in series to form two sensing channels, seven-core space division signals are multiplexed, the equivalent self-noise pressure suppression effect of the seven-core space division signals is analyzed, after noise correlation is removed through a time domain dislocation-frequency domain phase shift method, the signal-to-noise ratio gain can be increased to 8.65 dB, and the signal-to-noise ratio gain can be increased to 8.65 dB. And the detection capability of the system on low-frequency weak signals can be improved.

The invention discloses an equivalent self-noise pressure suppression method and device based on a multi-core optical fiber space division multiplexing signal, light emitted by a narrow linewidth laser is split through a first coupler C1, one path of light passes through an acousto-optic modulator AOM to generate a pulse signal, and then the pulse signal passes through a second coupler C2 to generate a pulse signal; the pulse light is divided into two beams of transmission light, the two beams of transmission light are injected into a connected sensing optical fiber through two groups of erbium-doped optical fiber amplifiers (EDFA), two groups of filters, two groups of circulators and a fan-in coupler Fan-in Coupler, and the pulse light is subjected to backward Rayleigh scattering in the sensing optical fiber; based on the dual-channel DAS system, the multi-core optical fiber serves as the sensing optical fiber, three cores and four cores of the multi-core optical fiber are connected in series to form two sensing channels, seven-core space division signals are multiplexed, the equivalent self-noise suppression effect of the seven-core space division signals is analyzed, and the detection capacity of the system for low-frequency weak signals can be improved.

The invention belongs to the technical field of photoelectronics, and particularly relates to a wide-spectrum narrow-linewidth semiconductor mode-locked laser, and the collaboration of a saturable absorption region SA and a resonator is reflected in time domain-frequency domain dual optimization. And the resonator optimizes the frequency domain characteristics through nonlinear broadening, phase synchronization and mode purification. The SA adjusts a mode locking threshold value in real time through dynamic bias voltage, the pulse energy stability is ensured, dispersion management of the resonator balances the SPM and group velocity dispersion, spectrum splitting is avoided, and the dissipative soliton form is maintained. Besides, due to heterogeneous integration of the InP-based SA and the SiN-based resonator, wafer bonding of the InP-based SA and the SiN-based resonator is realized, high-efficiency energy transfer is realized through the low-loss conical waveguide, a high-performance frequency comb with a wide spectrum and a narrow pulse width is output, and the high-performance frequency comb can be widely applied to the fields of ultrafast optics, coherent light communication and precision spectroscopy.

The invention relates to the technical field of semiconductor lasers, in particular to a DFB laser based on a top metal grating, and the DFB laser comprises a gain chip, the left end face of the gain chip is plated with a high-reflection HR film, and the right end face of the gain chip is plated with an anti-reflection AR film; the upper end face of the gain chip is provided with a ridge optical waveguide, and the upper end face of the ridge optical waveguide is provided with a metal Bragg reflection grating layer. A self-heterodyne interference method (the line width of a local oscillator is smaller than 500 Hz) is adopted, and the measured value of the 3dB line width is 50 Hz (the measured value of a traditional DFB is 125 kHz). The mode purity degree is verified through a Lorenzian fitting broadening factor 1.15; the wavelength drift is less than 0.05 pm / DEG C within the range of-40 DEG C to 85 DEG C after compensation of the temperature compensation circuit. The temperature tuning coefficient is 0.08 pm / DEG C, the current tuning coefficient is 0.05 pm / mA, and the tuning coverage range is 1530-1545 nm.

The invention relates to the technical field of laser precision machining, and particularly discloses a focus following control method and device for laser scribing. The method comprises the steps that processing parameters are set through upper software, and a two-way range finder is positioned; collecting material surface height data in real time, wherein analog voltage signals of the range finder and distance values are mapped according to a quantitative conversion relation; dynamically compensating the focus height deviation based on a PID algorithm; a voice coil motor is driven by a bus motion control card to adjust the position of a focus lens, and motor displacement and pulse are converted according to 10000 pulse / mm; and forward / reverse scribing respectively adopts independent range finder data to eliminate control lag errors. The device correspondingly comprises a two-way distance measuring module, a data processing module, an axis control module and a bus motion control card supporting multi-channel expansion. According to the invention, bidirectional ranging is combined with PID closed-loop control, and the line width error is controlled to be less than or equal to 20 [mu] m; 24-path synchronous focusing is supported, the focusing period is smaller than or equal to 10 ms, and the machining speed is larger than or equal to 2000 mm / s.

The invention discloses a multi-pass optical filter and a preparation method thereof, and the method comprises the steps: selecting a main reference channel, and carrying out the difference frequency modulation excitation through narrow linewidth laser, and obtaining optical transmission coupling data; performing periodic disturbance detection on the observation channel to obtain spectrum drift associated data; modulating deposition power and air pressure according to the spectrum drift associated data to form a crosstalk suppression layer; forming a three-layer dielectric structure with increasing optical thickness and a periodically changing coupling regulation layer on the crosstalk suppression layer; and performing temperature modulation annealing treatment to form an inter-channel steady-state coupling structure, and establishing a spectrum drift compensation parameter. The technical scheme of the invention can systematically characterize the correlation drift of the multi-channel spectral characteristic along with the micro process or service disturbance, accurately quantify the coupling relationship between different passbands, and solve the technical problem that the correlation drift between the passbands cannot be completely captured in the existing discrete measurement mode. The phenomenon of'array misfocus' in a miniature multispectral system is effectively avoided, and the precision and stability of the multi-pass optical filter are improved.

The invention discloses a municipal bridge expansion joint detection mechanism, and belongs to the technical field of expansion joint laser detection.The municipal bridge expansion joint detection mechanism comprises a main case and heat dissipation holes formed in the corners of the main case, guide columns are fixed to the side edges of the main case, and side width check blocks are arranged on the sides of the guide columns; a reference rod fixed to the side width check block is inserted into a guide column, a laser range finder is installed in the guide column, the laser range finder detects movement of the end of the reference rod through optics, and the middle of the side width check block is connected with a movable wheel through a rotating shaft. A first cleaning assembly and a second cleaning assembly are installed on the front side and the rear side of the movable wheel correspondingly. According to the municipal bridge expansion joint detection mechanism, through the arrangement of the laser range finder, the width of an expansion joint can be accurately measured conveniently, meanwhile, fixed-point or whole-line width measurement can be conveniently conducted on the expansion joint, and silt attached to the side wall of the expansion joint can be conveniently cleaned in the measurement process.

The invention provides a patterned photonic crystal laser and a preparation method thereof, the laser comprises a substrate, and a first mask layer, a photonic crystal layer and a second mask layer which are sequentially deposited on the substrate, a light emitting area is etched in the central area of the second mask layer, and transparent conductive layers are deposited on the surface of the second mask layer and the light emitting area; a p-annular electrode is arranged on the surface of the transparent conductive layer on the second mask layer, and an n-annular electrode is arranged below the substrate; the photonic crystal layer is composed of a nanorod array and a polymer filled in gaps of nanorods; holes distributed in a patterned array are etched in the surface of the first mask layer, and nanorods are epitaxially grown in hole areas; the nanorod is formed by sequentially depositing a substrate contact layer, a first waveguide layer, a multi-quantum well layer, a second waveguide layer, a coating layer and a component gradient layer. According to the invention, through collaborative design optimization of all the layers, emission of laser with specific wavelength and preparation of a laser emitting laser with single longitudinal mode, narrow linewidth and stable wavelength are realized.

The invention discloses an external cavity tunable laser linewidth compression system for realizing wavelength phase locking based on mutual injection of gain chips. The external cavity tunable laser linewidth compression system comprises a red light semiconductor laser main gain chip, a first collimation optical system, a blazed grating, a tuning rotating mirror, a reflector, a power supply driving system and a double-path feedback amplification system, the double-path feedback amplification system comprises a first secondary gain chip, a second secondary gain chip, a second collimation optical system, a third collimation optical system and a polarization-free beam splitter prism; and the red light semiconductor laser main gain chip, the first secondary gain chip and the second secondary gain chip are all connected with the power supply driving system. Therefore, the technical problems of low output infrared light power, poor stability and narrow mode-hopping-free tuning range in the prior art are solved, and high-power, narrow-linewidth, high-stability and large-range mode-hopping-free continuous tuning red light output can be realized.

The resist composition exhibits a high contrast, improved maximum resolution, and satisfactory sensitivity and line width roughness (LWR) when processed by lithography using high-energy radiation, especially electron beam (EB) and EUV, and a pattern forming process using the resist composition. The resist composition comprising (A) a base polymer containing a polymer comprising repeat units having an acid labile group and repeat units having a carboxy group, (B) an organic solvent, and (C) a hypervalent iodine compound having formula (1):

The invention discloses a low-divergence-angle narrow-linewidth high-power semiconductor laser. Relates to the technical field of semiconductor lasers, in particular to a low-divergence-angle narrow-linewidth high-power semiconductor laser. According to the invention, the parabolic waveguide structure is etched in the light field expansion area, and the metal reflector is introduced to realize a novel light field expansion and metal reflector integrated structure, and the transverse divergence angle of a laser mode is reduced through the expansion structure at the tail end of the waveguide. The laser comprises a laser gain area, a light field expansion area and a spectrum purification area at the tail of the light field expansion area. The laser gain region, the light field expansion region and the spectrum purification region at the tail part of the light field expansion region are made of the same laser epitaxial material in the longitudinal direction, the laser gain region is adjacent to the light field expansion region along the horizontal light emitting direction, and the light field expansion region is adjacent to the spectrum purification region at the tail part of the light field expansion region along the horizontal light emitting direction; the longitudinal direction is the direction from the substrate to the contact layer.

The invention discloses an on-line detection method for volatile organic compounds in waste gas, and belongs to the field of waste gas emission monitoring, the detection method comprises the following specific steps: I, starting a quantum cascade laser frequency comb of a middle infrared band, calibrating various parameters of the quantum cascade laser frequency comb, and ensuring to cover a characteristic absorption area of the volatile organic compounds in the waste gas; iI, inputting the waste gas into a gas detection chamber through a sampling pipeline, monitoring the state of the waste gas in real time, and dynamically adjusting the conditions of the gas detection chamber according to various collected signals; the device can capture instantaneous fluctuation of waste gas concentration in real time, meets the high-speed dynamic emission monitoring requirement, has extremely high coherence and narrow linewidth, can analyze tiny spectral line differences which cannot be distinguished by a traditional spectrograph, remarkably improves the detection precision and the recognition capability, ensures that a measurement result still keeps consistency and high reliability under different working conditions, and is suitable for large-scale popularization and application. The signal-to-noise ratio is obviously improved, the power drift is reduced, and long-time stable operation is realized.

According to the optical fiber interference sensor and the application method thereof, an electro-optical frequency comb is introduced to screen out two comb lines to form a photon-assisted millimeter wave light source, interference is carried out in two frequency spectral regions subsequently, common phase fluctuation is counteracted based on inherent phase coherence, and the strict requirement for the line width index of a laser is avoided. Meanwhile, the two acoustic optical modulators connected in parallel are introduced into the reference arm and the interference arm for frequency shift, the problem of co-frequency crosstalk caused by residual zero-order diffraction of the acoustic optical modulators is solved, and the sensing precision is substantially improved.

The invention discloses a non-contact drunk driving detection method and system adopting a large-linewidth tunable laser, and relates to the technical field of laser detection, and the method comprises the steps: collecting transmission light signals and corresponding electric signals under different linewidth conditions through experiments, synchronously recording experiment parameters, obtaining an original data set, carrying out the preprocessing of the original data set, and carrying out the detection of drunk driving. Generating a training set, a verification set and a test set, and training a BP (Back Propagation) neural network to obtain a pre-trained noise suppression model; the method comprises the following steps of: generating a wavelength-tunable modulated laser beam by adopting a large-linewidth tunable laser, directionally projecting the modulated laser beam into a vehicle cab, and enabling laser to penetrate through the cab space and carry alcohol gas concentration information to obtain a transmission light signal; focusing the transmission light signal to a photoelectric detector through an optical convergence device to obtain a noisy electric signal, inputting the noisy electric signal into a pre-trained noise suppression model, and outputting a de-noised electric signal; performing synchronous demodulation and harmonic analysis on the de-noised electric signal by using a phase-locked amplification detection technology, extracting a second harmonic signal amplitude associated with the modulation frequency, and determining a second harmonic signal characteristic amplitude through peak detection; according to the calibration relation between the second harmonic signal characteristic amplitude and the alcohol gas concentration, the concentration value of the alcohol gas in the cab is calculated in an inversion mode through a least square fitting algorithm, an alcohol concentration threshold value is set, the drunk driving condition of a driver is judged, a detection result is generated, and an alarm signal is output.

The invention relates to the technical field of optical parameter measurement, in particular to an optical fiber nonlinear refractive index measurement method and system based on a narrow linewidth signal, and the method comprises the steps: obtaining the initial length of an optical fiber and the wavelength parameter and a plurality of power values of a laser group connected with a to-be-measured optical fiber, and calculating the effective length value of the optical fiber based on the initial length; main peak power and side peak power corresponding to the multiple power values are obtained, the power ratio of the main peak power and the side peak power is calculated, the power ratio is input into a calculation model for inversion calculation to obtain the corresponding target phase shift amount, and the power values and the corresponding phase shift amount are fitted to determine intermediate parameters; and calculating the nonlinear refractive index of the optical fiber by combining the intermediate parameter, the wavelength parameter and the effective length value. The technical problems that in the prior art, the calculation process is complex and is easily interfered by the dispersion effect, and the nonlinear effect intensity is unstable, so that the accuracy of the nonlinear refractive index of the optical fiber is low are solved. The method has the effects of reducing the calculation complexity of the nonlinear refractive index of the optical fiber and improving the accuracy at the same time.

The invention discloses a seawater temperature, salinity and sound velocity inversion method based on a Brillouin laser radar, and belongs to the technical field of marine environment monitoring. According to the method, the temperature, salinity and sound velocity of seawater are inverted by measuring the Brillouin frequency shift and the Brillouin line width and combining the MLP neural network; the method specifically comprises the steps of collecting seawater parameter data of different sea areas, different seasons and different depths and corresponding frequency shifts and line widths; carrying out data preprocessing and standardization on the collected data; and establishing an inversion model by using an MLP neural network, and outputting temperature, salinity and sound velocity. The multi-layer perceptron MLP neural network processes frequency shift and line width data measured by the Brillouin laser radar, high-precision and real-time inversion of seawater temperature, salinity and sound velocity is achieved, the parameter range is remarkably expanded, the inversion precision is improved, and efficient and reliable marine environment monitoring is provided.

The invention discloses an image analysis method and system for quality control traceability of a satellite navigation board, and relates to the technical field of image processing. The method comprises the following steps: synchronously acquiring an image and three-dimensional point cloud data of a radio frequency transmission line area through a high-resolution area array CCD camera and a laser contourgraph; acquiring a transmission line contour based on image identification, and constructing a three-dimensional radio frequency line model through point cloud fitting; detecting the line width and the distance to the ground plane by using the model, and calculating the impedance prediction complexity in combination with a data acquisition error; dynamically calling a characteristic impedance prediction engine based on the complexity to obtain a predicted characteristic impedance sequence; and quality defect judgment is carried out, and traceability control is carried out on defective products. According to the method, a complete technical chain from geometric dimension detection to electrical performance evaluation is established, hidden defects which are difficult to find by a traditional method can be effectively identified, and the quality control precision and the product yield of the satellite navigation board are improved.

The invention relates to a single laser printing device and method capable of modulating line width. The device comprises a focusing unit, a galvanometer unit, a light beam adjusting module and an angle adjusting module, wherein the light beam adjusting module and the angle adjusting module are sequentially arranged in front of laser light paths of the focusing unit and the galvanometer unit; the light beam adjusting module is used for modulating circular laser into long-strip-shaped laser and modulating the length of the long-strip-shaped laser according to the size of a pattern at a printing position when the same straight line is scanned; the long-strip-shaped light beams are always parallel to one another during galvanometer scanning, and laser energy in variable-width lines scanned by the galvanometer is evenly distributed. The angle adjusting module is used for adjusting the line width direction of the long-strip-shaped laser to be perpendicular to the scanning direction of the galvanometer unit. For different positions in each printing area, the laser is modulated into long-strip-shaped laser with the width consistent with the width of an image at the printing position through the light beam adjusting module, then the width direction of the long-strip-shaped laser is perpendicular to the scanning direction of the galvanometer through the angle adjusting module, and scanning of one printing area can be achieved only through one-time scanning of the galvanometer unit. And the printing precision is ensured while the printing efficiency is greatly improved.

The invention discloses a semiconductor narrow linewidth laser temperature cycle test system and a test method thereof, which belong to the field of laser communication and eliminate errors caused by system loss to optical power measurement through optical power calibration compensation coefficients. The variable-temperature adjustment is controllable, the wavelength of the laser is efficiently tuned, and various indexes are measured. The device mainly comprises a plurality of drivers and a high-low temperature test box, to-be-tested laser parts of a plurality of tested lasers are placed in the high-low temperature test box, and other parts of the tested lasers are located outside the high-low temperature test box so as to avoid the influence of equipment temperature drift on measurement; the plurality of drivers are respectively and correspondingly connected with the plurality of tested lasers, optical chip driving current and TEC closed-loop temperature control are provided for the tested lasers, wavelength tuning of the lasers is realized through the TEC closed-loop temperature control system, and temperature sensors are arranged at the tested lasers in the high and low temperature test box. The invention is mainly used for the semiconductor narrow linewidth laser temperature cycle test system.

The invention discloses an equivalent self-noise pressure suppression method based on a dual-channel distributed acoustic sensing system, and the method comprises the steps: carrying out the light splitting of light emitted by a narrow-linewidth laser through a first coupler C1, enabling one path of light to generate a pulse signal through an acoustic optical modulator (AOM), enabling the other path of light to pass through a second coupler C2, and enabling the other path of light to pass through a second coupler C1; the pulse light is divided into two beams of transmission light, the two beams of transmission light are injected into a connected sensing optical fiber through two groups of erbium-doped optical fiber amplifiers (EDFA), two groups of filters, two groups of circulators and a fan-in coupler Fan-in Coupler, and the pulse light is subjected to backward Rayleigh scattering in the sensing optical fiber; according to the invention, based on a dual-channel DAS system, two fiber cores of the multi-core optical fiber are used as sensing optical fibers, and the space division signals of the two cores are multiplexed, so that the performance that the equivalent self-noise pressure drop is 2.54 dB in the frequency band of 100-1000Hz is realized under the condition that the noise correlation coefficient of the dual-core signals is 0.11, and the detection capability of the system on low-frequency weak signals can be improved.

The invention relates to the technical field of semiconductor lasers, in particular to an ultra-narrow linewidth wavelength-adjustable external cavity laser based on a planar metal grating, which comprises a gain chip, and the left end face and the right end face of the gain chip are respectively plated with a high reflection film and a first antireflection film; a planar metal grating waveguide is arranged on the right side of the gain chip, the right end face of the gain chip is aligned and attached to the left end face of the planar metal grating waveguide, and a second antireflection film and a third antireflection film are plated on the left end face and the right end face of the planar metal grating waveguide respectively; the planar metal grating waveguide comprises a grating waveguide substrate, a ridge optical waveguide is arranged on the upper portion of the grating waveguide substrate, an annular resonance optical waveguide is arranged on the front side of the ridge optical waveguide, a planar metal grating is arranged on the upper portion of the ridge optical waveguide, and a top covering layer is arranged on the upper portion of the planar metal grating. Through the centimeter-level metal grating and the low-loss coupling structure, light beam quality with 3dB line width less than 700Hz and M2 less than 0.9 is realized.

The invention provides a BOTDR (Brillouin optical time domain reflectometry) system fusing Stokes-anti-Stokes light and a demodulation method, and belongs to the technical field of Brillouin distributed optical fiber sensing. The narrow linewidth laser is used for generating continuous optical signals; the input end of the coupler is connected with the laser, and the output end is connected with the pulse light branch and the local oscillator light branch. The pulsed light branch comprises a semiconductor optical amplifier, a random scrambler, a first erbium-doped optical fiber amplifier and a circulator which are connected in sequence; the local oscillator light branch comprises an electro-optical modulator, and the electro-optical modulator regulates and controls sideband frequency through a microwave module; the second erbium-doped optical fiber amplifier is used for extracting the Stokes light and the anti-Stokes light; the single-mode coupler mixes the double-sideband local oscillator light with the anti-Stokes light and the Stokes light; and the electrical beat frequency signals are acquired, filtered and enveloped and demodulated through an acquisition card. The detection capability of the Brillouin scattering signal is enhanced, the system structure is simplified, and the hardware cost and the maintenance difficulty are reduced.

Disclosed is a linear array scanning Brillouin scattering elastic imaging device. In the device, a signal generating system consists of a narrow linewidth continuous wave laser, a half-wave plate, a beam expander, a Y-direction scanning galvanometer, a microlens array, a pinhole array filter, a first plano-convex lens, a polarization beam splitter, a quarter-wave plate and a microscope objective. A signal receiving system consists of a microscope objective, a quarter-wave plate, a polarization beam splitter and an eight-channel optical collimator array. Each channel of an eight-channel spectrometer consists of an optical collimator, a convex lens, a scanning Fabry-Perot interferometer, a photomultiplier tube and an eight-channel photon collection card.

The invention discloses a high-spatial-resolution distributed optical fiber sound wave sensing system based on FPGA real-time demodulation. The system comprises a narrow linewidth laser source module, a first coupler, a high-bandwidth sweep frequency signal modulation module, a circulator, a coherent receiving and photoelectric conversion module and an FPGA integrated module. A laser source emitted by the narrow linewidth laser source module is divided into about 10% of reference light and about 90% of detection light through the first coupler. The FPGA integrated module is connected with the high-bandwidth sweep frequency signal modulation module, and transmits a sweep frequency radio frequency pulse signal and a frequency shift radio frequency pulse signal to the high-bandwidth sweep frequency signal modulation module; the high-bandwidth sweep frequency signal modulation module is connected with the sensing optical fiber through the circulator so as to output sweep frequency optical pulses; the sensing optical fiber is connected with the coherent receiving and photoelectric conversion module through the circulator to transmit Rayleigh backscattered light; the coherent receiving and photoelectric conversion module is connected with the FPGA integrated module, and the FPGA integrated module carries out signal processing to obtain vibration information on the optical fiber.

The invention discloses an integrated optical signal receiver and method, particularly relates to the field of optical communication, is used for solving the problem of video stream transmission quality reduction caused by optical signal distortion in a low optical signal-to-noise ratio environment, and aims to eliminate cross coupling caused by a birefringence effect by constructing a dynamic polarization state transfer matrix. Generating a clear independent polarization state electric signal sequence; time-frequency domain processing is carried out on the electric signal sequences, linear phase noise caused by laser linewidth and phase deviation caused by an optical fiber nonlinear effect are compensated, and signals with higher phase accuracy are output; then, the signals are mapped to a four-dimensional constellation space, a clustering method is used for generating an adaptive judgment boundary, symbol judgment is optimized, and the anti-noise capability is improved; through cooperative work of an inner loop and an outer loop, system parameters are dynamically adjusted according to signal characteristics, and processing stability and adaptability are enhanced. And finally, performing soft decision decoding on the signal, improving the decoding accuracy in combination with phase residual correction, and outputting a reconstructed video data stream.

The invention discloses a wafer scribing process, which comprises the following steps of: amplifying the line width of a saw street dummy copper conductor and continuously filling to form a shearing buffer copper strip; performing double-pulse laser annealing on the shear buffer copper strip to generate a twin crystal softening layer; back infrared gradient preheating is carried out according to the thermoplastic transition temperature of the copper strip, the feeding rate and the rotating speed of a tool are corrected in combination with vibration data coupling, and a plastic initial saw kerf is obtained; layering progressive deep cutting is carried out according to multi-gear cutting depth data, so that the copper strip slides to absorb energy under the pulse load and is elastically reset through a low dielectric layer, and a full-depth saw kerf is formed; and performing constant-temperature crystal locking and gradient cooling in a nitrogen environment, so that the twin crystal structure of the copper strip is stable and is interlocked with the dielectric layer shrinkage hoop, and a flexible bridging unit is generated on the side wall of the saw kerf. According to the technical scheme, the interlaminar shear stress can be subjected to peak clipping and shunting at the cutting moment, selective layering of a multi-layer interconnection interface is inhibited, and the yield and long-term reliability of the ultrathin wafer are improved.