843 results about "Line width" patented technology

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 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 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.

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 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 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 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 relates to the technical field of laser light source measurement, and discloses a wide-range narrow-linewidth laser wavelength and linewidth measurement system, which can be flexibly matched with the center frequency of laser to be measured through the arrangement of a tunable laser, breaks through the strict limitation of the existing beat frequency method on the center frequency, effectively expands the measurement range, and improves the measurement accuracy. By combining the synergistic effect of the absorption cell and the locking loop, the system stability is improved, the measurement precision of narrow linewidth laser is guaranteed, the integration time can be flexibly adapted without tedious adjustment of a delay optical path or change of parameters of acquisition equipment through the cooperation of the optical modulator and the delay optical fiber, the problem of inconsistent measurement resolution under different integration time is avoided, and the measurement accuracy is improved. And the accuracy of short-time measurement is obviously improved. The system integrates wavelength and line width measurement functions, can measure line width, center wavelength and long-time frequency stability of to-be-measured laser, is reasonable in structural design, retains the advantage of high precision of a beat frequency method, overcomes the defects that an existing method is narrow in measurement range and inconvenient to adjust integral time, and improves the measurement accuracy of the to-be-measured laser. And the measurement requirements of wide-range and narrow-linewidth laser are met.

The invention relates to the technical field of optoelectronic devices, in particular to a laser based on two different gratings and a metal grating with a phase interval of lambda / 2, which comprises a gain chip, a gain chip optical waveguide, an optical waveguide substrate, an optical waveguide, an annular resonant optical waveguide and a metal BRAGG reflecting grating. A unique outer cavity structure is adopted, a traditional interlayer semiconductor grating is abandoned, a top metal grating is adopted, a traditional DFB sandwich type secondary epitaxy manufacturing process is greatly simplified and avoided, the production cost is reduced, particularly, the metal grating is divided into two parts with similar but different grating constants, and the phase positions of the two gratings are pulled by lambda / 2, so that the performance of the DFB is improved. According to the design, the side mode rejection ratio (SMSR) of laser beams can be effectively improved, the laser line width is compressed, a guarantee is provided for stable work of the laser in a high-performance application scene, and the grating reflection efficiency is effectively improved by combining a'mouth-to-mouth 'coupling butt joint mode of the gain chip and the optical waveguide substrate.

The invention provides a narrow-linewidth single-frequency laser frequency stabilization system and method based on a Gaussian filter, and the system employs the Gaussian filter to reduce the optical power of single-frequency laser, and employs the frequency selection characteristic of the Gaussian filter, the frequency spectrum of the single-frequency laser is a single narrow peak, and the frequency stability of the single-frequency laser is improved. When laser frequency passes through a designed Gaussian filter (the fluctuation range of a frequency-stabilized laser source is only on the left side of the center frequency of the Gaussian filter), laser signals can be reduced according to a Gaussian function rule, and along with frequency change, attenuation degrees are different and monotonically change, so that output optical power is different, and the output optical power is changed. And the optical power is compared with the optical power of a preset frequency stabilization target (a half-high point on the left side of a Gaussian filter) to obtain the deviation of the laser source relative to the target frequency stabilization frequency, so that the laser frequency is correspondingly adjusted to achieve the frequency stabilization purpose. The high-sensitivity optical power detection is realized, the response speed and the frequency stabilization precision of the system are improved, and the system is simple in structure and low in maintenance cost.

The invention relates to the technical field of semiconductor lasers, in particular to an external cavity laser for realizing narrow linewidth through phase difference regulation and control of a bimetallic Bragg grating, 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, an annular resonance optical waveguide is arranged on the front side of the ridge optical waveguide, 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. Tests show that the side mode rejection ratio (SMSR) is increased to 65dB and the line width is compressed to 0.6 kHz by using an interference enhancement effect and a mode suppression mechanism.

An FM LIDAR system is described that includes a frequency modulated LIDAR system that incorporates a laser source that is optically coupled to a whispering gallery mode optical resonator. Light from the laser that is coupled into the whispering gallery mode optical resonator is coupled back out as a returning counterpropagating wave having a frequency characteristic of a whispering gallery mode of the optical resonator. This returning wave is used to reduce the linewidth of the source laser by optical injection. Modulation of the optical properties of the whispering gallery mode optical resonator results in modulation of the frequency of the frequencies supported by whispering gallery modes of the resonator, and provides a method for producing highly linear and reproducible optical chirps that are highly suited for use in a LIDAR system. Methods of using such an FM LIDAR system and vehicle assisting systems that incorporate such FM LIDAR systems are also described.

The invention relates to the technical field of optical elements, in particular to a structural color regulation and control device based on silicon nitride metasurface continuous domain bound state enhancement, which comprises a substrate and a metasurface structure arranged on the substrate, the substrate is a silicon dioxide substrate, and the metasurface structure is composed of a plurality of nano-disks which are periodically arranged in a two-dimensional manner. And a circular air hole is formed in the nano plate. Based on the narrow linewidth resonance characteristic of the quasi-BIC, the structural color with high saturation and wide color gamut is realized; by utilizing strong polarization dependence, passive and dynamic regulation and control of color brightness can be realized through simple polarization rotation, and the structure does not need to be changed; silicon nitride has extremely low loss in a visible light band, good compatibility with a silicon dioxide substrate and a stable structure; a high-contrast polarization encryption pattern is easy to realize, and the application prospect in the fields of high-end anti-counterfeiting, information storage, dynamic display and the like is wide; the adopted micro-nano processing technology is standard and mature, and practical preparation and industrialization of the device are facilitated.

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, an annular resonance optical waveguide is arranged on the front side of the ridge optical waveguide, 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 present invention relates to the field of communication and sensing, and specifically to a communication and sensing integrated device based on a seven-core optical fiber interferometer and an application method therefor. The application method comprises: a first beam splitter splitting, into reference light and signal light, a light source emitted by a narrow linewidth laser; performing modulation by means of a first coherent optical transmitter and a second coherent optical transmitter; amplifying the light by means of a first amplifier and a second amplifier, and then enabling the light to pass through a multi-core optical fiber from a fan-in end, and to output from a fan-out end; performing beam splitting by means of a second beam splitter and a third beam splitter, and performing demodulation by means of a first coherent receiver and a second coherent receiver; and finally, a phase-locked loop performing interference elimination on preliminarily-demodulated reference light and preliminarily-demodulated signal light to obtain finally-demodulated reference light and finally-demodulated signal light. The present invention uses a phase-locked loop to further eliminate disturbance noise of reference light and signal light. Therefore, noise interference is eliminated in continuous low-frequency detection, thereby improving the communication and sensing effect.

The invention discloses a mode-hopping-free scanning control method for a narrow-linewidth laser, and belongs to the technical field of laser control. The method comprises the following steps: generating a reference current scanning signal and a reference voltage scanning signal; generating a high-frequency jitter signal, and superposing the high-frequency jitter signal with the reference current scanning signal to generate a total injection current for driving the narrow linewidth laser; acquiring a real-time optical power feedback signal of the narrow linewidth laser; according to the optical power feedback signal and the high-frequency jitter signal, a mode margin error signal is generated through demodulation, and the mode margin error signal is used for representing the mode stability of the current working state of the narrow linewidth laser; and generating a dynamic correction voltage according to the mode margin error signal, and superposing the dynamic correction voltage and the reference voltage scanning signal to generate a total driving voltage for driving piezoelectric ceramics of the narrow linewidth laser. Through predictive feed-forward correction, mismatch is compensated and controlled in real time, and the mode hopping phenomenon is effectively inhibited.

The invention relates to a multi-path high-stability narrow-linewidth external cavity semiconductor laser and application thereof, and belongs to the technical field of lasers. The laser comprises two groups of external cavity light paths, Z-block beam combiners, partial reflectors and isolators, the two groups of external cavity light paths are arranged side by side, and the Z-block beam combiners, the partial reflectors and the isolators are sequentially arranged on the light emitting sides of the two groups of external cavity light paths; the external cavity optical path comprises a gain chip, a collimating lens, a polarization analyzer A, a polarization beam splitter, an F-P etalon and a narrow-band-pass filter which are sequentially arranged along the optical path. The polarization analyzer and the polarization beam splitter are arranged in the external cavity light path, main polarized light is kept to resonate in the external cavity light path, the polarization suppression ratio of the external cavity light path is improved, non-dominant mode noise is suppressed, and the line width is reduced; the mode jump risk is reduced, the device life is prolonged, and the power stability is improved; the beam quality is improved; and the polarization dependent loss in a light path is reduced.

The invention particularly relates to an excitation signal waveform intelligent optimization method for a high-power narrow-linewidth fiber laser, and the method comprises the steps: obtaining an excitation signal, carrying out the processing of a phase modulation waveform of the excitation signal, and extracting an input feature set needed by frequency spectrum prediction; constructing a frequency spectrum prediction model based on the decoupling echo state network, inputting the input features into the frequency spectrum prediction model based on the decoupling echo state network, realizing nonlinear mapping between the phase modulation waveform of the excitation signal and the frequency spectrum response thereof, and obtaining a prediction frequency spectrum; constructing a composite cost function including a mean square error, a spectrum sideband leakage penalty term and a spectrum smoothing term based on the difference between the predicted spectrum and the target spectrum; based on a composite cost function, an Adam optimization algorithm is adopted to iteratively correct a phase waveform in a frequency domain, intelligent waveform optimization of phase modulation is realized, and a threshold value of a stimulated Brillouin scattering effect is reduced. The intelligent optimization of the phase modulation waveform of the excitation signal can be realized.

The invention provides a multi-light-path spacing adjustment scribing control system and method for a perovskite scribing device. Aiming at the technical problems of insufficient multi-path laser line spacing uniformity, poor track following synchronism and low line width and line depth stability in perovskite solar cell laser processing, a control system is constructed by integrating a laser emission module, a visual positioning module, a light path spacing adjustment module, a track cooperative control module and a laser focus compensation module; by correcting the line spacing deviation and the track deviation in real time and dynamically adapting to the flatness change of the surface of the substrate, the processing defects caused by mechanical adjustment response lag, track dislocation and focus fixation in the traditional technology are effectively overcome, the line spacing uniformity, the track synchronization precision and the line width and line depth stability are obviously improved, and the production efficiency is improved. The dynamic line spacing switching response time is less than or equal to 1 second, the mass production requirement of large-size substrates can be met, and technical support is provided for efficient large-scale production of perovskite cells.

The invention relates to the technical field of non-linear regulation and control, in particular to a non-linear regulation and control method for a high-power narrow-linewidth multi-tone fiber laser system, which comprises the following steps: analyzing an influence mechanism of key parameters in the multi-tone fiber laser system on a non-linear effect; on the basis of the analyzed influence mechanism, establishing a nonlinear kinetic equation for describing the interaction of the pump wave, the stokes wave and the sound wave by combining a three-wave coupling theory, and forming a nonlinear propagation model; designing a Tab-DDPM generation network based on a nonlinear propagation model, and modeling a reverse mapping relation between a performance index and a design parameter by using a conditional diffusion mechanism to realize prediction of an optimal parameter; and inputting the optimal parameter into the nonlinear propagation model for verification, extracting an actually output performance index, and comparing the actually output performance index with a set target index to realize nonlinear performance evaluation and closed-loop optimization regulation and control. According to the method, the output capability and the signal fidelity of the high-power fiber laser system are effectively improved, and the method has good generalization capability.

The invention discloses a navigation guide element adjusting method and device and a processor. When the method provided by the embodiment of the invention is executed, light machine projection parameters of head-up display projection equipment in a target vehicle in a guiding state and the eye height of a driver are firstly collected; then, a visual perception area is determined based on light machine projection parameters and the eye height of a driver, so that a dynamic perception area is delimited; and finally, acquiring the number of opaque pixels (namely, opaque pixel values) and the total number of pixels in the standard rectangle and the total number of opaque pixels in the whole dynamic sensing area, and dynamically adjusting the line width of a navigation guide element projected by the head-up display projection equipment according to the indexes. By adjusting the line width of the navigation element, the coverage area of the opaque pixel can be effectively controlled, and excessive shielding of important information is avoided, so that the driving safety is improved.

The invention belongs to the technical field of antennas, and discloses a reflection unit based on a metasurface and an array antenna thereof. Comprising a linear polarization horn antenna feed source and a metasurface reflection array. The array is composed of reflection units which are arranged periodically, and each reflection unit comprises a metal resonance layer, a dielectric substrate and a metal back plate from top to bottom. The metal resonance layer comprises a non-uniform line width structure formed by a central metal strip and two symmetrically connected arc-shaped metal arms, namely, the line width of the central metal strip is unequal to that of the arc-shaped metal arms, so that the loss of the reflection unit is effectively reduced, and coupling between amplitude and phase regulation is remarkably reduced. The reflection phase of the reflection unit is realized by adjusting the central angle corresponding to the arc-shaped arm, and the reflection amplitude is realized by adjusting the rotation angle of the whole metal resonance layer around the normal axis of the metal resonance layer. Through joint optimization of parameters and array arrangement of each unit, excellent performance of low sidelobe level, low cross polarization level and high aperture efficiency is finally realized.

The invention relates to the technical field of optical interference measurement, in particular to a synchronous wavelength phase-shifting interference measurement system. According to the scheme, a laser set outputs multiple narrow-linewidth light beams with nm-level wavelength spacing, and the multiple narrow-linewidth light beams are combined through a wavelength division multiplexer and then enter an interference light path to generate multi-wavelength interference fringes. The metasurface achieves separation of interference fringes of all wavelengths through a sub-wavelength structure array, a detector synchronously captures light intensity data of the interference fringes of all the wavelengths in a single frame mode, and then phase distribution can be directly calculated through single-frame multi-wavelength light intensity. According to the system, mechanical phase shifting and polarization control assemblies are eliminated, the defects that a traditional wavelength phase shifting interference measurement technology is poor in environmental adaptability and a traditional synchronous phase shifting technology has polarization errors are overcome, and a high-precision and high-environmental-adaptability dynamic measurement scheme is provided for optical manufacturing.

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 present strain gauge includes a substrate and a resistor formed on the substrate. The resistor is made of a material mainly composed of Cr. A line width W and the film thickness T of the resistor are in a relationship of satisfying an expression (1) below such that the strain gauge has a transverse sensitivity ratio of 70% or less and a gauge factor of 5 or greater. w≤0.0177t2+0.1521t+2.9541—(1). In the expression (1), w=log W and t=log T.

The application provides an optical system and a monitoring method for monitoring stimulated Brillouin scattering effect. The optical system for monitoring stimulated Brillouin scattering effect firstly delivers a narrow linewidth seed source into a laser amplifier through a first optical device to amplify the narrow linewidth laser, and guides stimulated Brillouin scattering light generated by the laser amplifier to a back light monitoring module to detect the back light power and spectral components of the stimulated Brillouin scattering light in real time through the back light monitoring module, so as to realize the purpose of simultaneously and accurately measuring the stimulated Brillouin scattering light power and observing the laser components, and is more conducive to judging whether the stimulated Brillouin scattering effect occurs. Further, the optical system can adjust the light splitting ratio of the first optical device and the back light monitoring module to protect the narrow linewidth seed source and the spectrometer in the back light monitoring module from the damage of the back light to the greatest extent, and achieve the purpose of accurately judging the stimulated Brillouin scattering effect and protecting the system safety.