186 results about "Laser intensity" patented technology

The invention discloses a LiDAR-IMU-camera tight coupling positioning and mapping method and device for a mobile platform, and belongs to the technical field of robot SLAM. Synchronously triggering the color camera, the laser radar and the IMU through hardware, and unifying timestamps; performing compensation and distortion removal on the laser point cloud motion by the IMU data; based on curvature, intensity and density self-adaptive downsampling, local plane fitting errors are used for distributing observation weights; the IMU pre-integration pose is used as an initial value, point-to-surface registration of the weighted point cloud and the local map is carried out, and a laser-IMU tight coupling odometer factor is obtained; the color image and the laser intensity graph are fused into a multi-mode loopback descriptor, and loopback factors are generated through global retrieval and geometric verification; and inputting an odometer, an IMU, a laser loopback factor and a visual loopback factor into an increment factor graph optimizer, jointly solving a global optimal key frame pose, and outputting a dense laser point cloud map and a color visual point cloud map. The method can be operated in real time on an embedded platform, effectively inhibits drifting, and realizes centimeter-level global consistent positioning and mapping.

The invention discloses an all-optical three-dimensional scanning confocal fluorescent microscopic imaging device and an implementation method thereof. According to the invention, through a deep learning driven adaptive regulation and control method, CNN is adopted to process spatial distribution data and dynamically regulate and control a phase hologram and the light intensity and phase compensation of a laser, so that the focal point of exciting light is subjected to aberration-free axial displacement, a bidirectional parallel optical scanning track of a two-dimensional scanning system is optimized, and all-optical three-dimensional scanning is realized; lSTM and TCN are combined to obtain a time sequence dependency relationship, a laser light source, an adjustable diaphragm, an electric focus-adjustable lens and a photoelectric detector are integrally controlled, efficient synchronization and automatic operation and high-speed axial focusing adjustment are realized, errors and time sequence mismatch are eliminated, optical characteristics of different samples and environmental interference are automatically adapted, and high-quality imaging is kept. The robustness and the applicable scene range of the system are improved; the method is used for model biological embryo real-time tracking, intracellular signal molecule dynamic visualization, cell membrane protein migration and aggregation observation and intracellular organelle interaction tracking.

The invention relates to the technical field of lane edge detection, and provides a multi-source feature lane edge line identification method and system based on a scoring mechanism, and the method comprises the following steps: obtaining and preprocessing road point cloud data, and obtaining road region point cloud data; the color information and the laser intensity information are fused for scoring, and the road area point cloud is processed to obtain a lane line point cloud; for the lane line point cloud, extracting boundary points based on the central main axis and the normal feature jump score to obtain an edge line of each lane line; and performing smooth fitting on the edge line of the lane line to obtain a fitted lane edge line. According to the method, the color and laser intensity double-scoring function is constructed, the intensity threshold is adaptively determined through the OTSU algorithm, and the intensity threshold and RGB color difference are subjected to weighted fusion, so that the recognition accuracy and continuity of the lane marking points are effectively improved, and the problems of extraction fracture, misrecognition and the like in a traditional method are solved.

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

The invention relates to a laser processing system (1) having at least one laser source (3, 4) for generating a plurality of mutually independent laser intensity distributions (5, 6). The laser processing system (1) comprises a control device (7) for controlling the laser power levels (P1, P2, 13, 14) and / or the beam quality levels (K1, K2, 14, 16) of the laser intensity distributions (5, 6) independently of one another. The laser processing system (1) is designed to vary the laser power levels (P1, P2, 13, 15) and / or the beam quality levels (K1, K2, 14, 16) of the laser intensity distributions (5, 6) differently from one another within each laser pulse by means of the control device (7). The invention also relates to a corresponding method for processing material (2) by means of corresponding laser radiation (5, 6).

The application relates to a detection method and system for measuring residual oxygen concentration by laser, and relates to the field of gas concentration detection. The method comprises the following steps: selecting laser with oxygen absorption peak wavelength as detection laser, applying a periodically changed modulation signal to form a modulation laser and irradiate the headspace, demodulating a direct current component from the modulation laser passing through the headspace, calculating a deviation rate according to the direct current component and a reference direct current, judging whether the deviation rate is within a threshold value, feeding back and adjusting the laser wavelength if the deviation rate is not within the threshold value, and finally outputting a laser intensity attenuation curve of residual oxygen to obtain the residual oxygen concentration. The detection system comprises an optical subsystem, an electrical subsystem, a feedback control subsystem and a data processing subsystem. The application can accurately measure the residual oxygen concentration in the headspace, effectively detect and correct the laser wavelength drift, and improve the measurement precision and stability.

The utility model belongs to the technical field of optical instruments, and particularly relates to an optical tweezer optical path module and a cell optimization system. The optical tweezer optical path module comprises a supporting base, a laser head mounting seat and a multi-stage attenuation module. The laser head mounting seat is arranged on the supporting base and is used for mounting a laser emitting head for emitting laser; and the multi-stage attenuation module is arranged on the supporting base and comprises a plurality of reflection attenuation mirror groups which are arranged on the light path at intervals, and each reflection attenuation mirror group is used for attenuating the laser intensity and changing the laser direction. The optical tweezer optical path module provided by the utility model has a multi-attenuation mechanism, and a relatively large attenuation multiple range is easier to realize, so that laser power adjustment in a relatively large range is realized, the laser power dynamic adjustment capability is favorably improved, the laser intensity is finely controlled, and cells are not damaged when various cells are fixed through an optical trap formed by laser.

In an example, the present invention provides a system including a light source configured to generate a laser. The system has an optical enhancement cavity coupled to the light source and configured to increase an intensity of the laser and a cavity dumper coupled to the optical enhancement cavity. The system has an acoustic wave coupled to the cavity dumper to diffract the laser.

The invention discloses a method for calculating and eliminating laser intensity modulation and carrier phase delay in a modulation absorption frequency stabilization system, and belongs to the technical field of semiconductor laser frequency stabilization and precision detection. In order to improve the stability and accuracy of the output center frequency of the laser, a modulation absorption frequency stabilization system is built; executing a coarse adjustment stage of laser intensity modulation and carrier phase delay parameters, and obtaining a phase difference between light frequency modulation and light intensity modulation; a fine stepping optimization stage is executed, laser intensity modulation and carrier phase delay parameter calculation are completed, and the updated phase corresponding to the maximum peak-to-peak value of the light intensity absorption 1f signal and the phase corresponding to the maximum value of the extreme value difference of the light intensity absorption 2f signal are obtained; performing elimination processing to obtain a light intensity absorption 1f signal after elimination processing; and for the modulation absorption frequency stabilization system, residual light intensity fluctuation caused by current modulation on the tunable semiconductor DFB laser is eliminated by using a light intensity stabilization device. The stability and the accuracy of the output center frequency of the laser are improved.

The present application relates to the technical field of sensor data calibration, and specifically relates to a multi-sensor data calibration processing method, system and medium, the method comprising: obtaining at least two sensor data and standard second harmonic signal data; obtaining the second harmonic signal data corresponding to the laser intensity signal from the sensor data; determining the harmonic abnormal feature, the first difference rate and the second difference rate according to the second harmonic signal data and the standard second harmonic signal data; determining the calibration error parameter according to the harmonic abnormal feature, the first difference rate and the second difference rate; based on the calibration error parameter, the initial detected target gas concentration is calibrated to obtain the calibrated target gas concentration. The present application can correct the initial detected target gas concentration according to the calibration error parameter, improve the calibration accuracy, and further reduce the deviation between the sensor detected gas concentration and the real gas concentration.

A method for characterizing a resonator element (102) is provided, the method comprising the steps of providing laser light having a tunable carrier frequency and coupling at least a first portion of the laser light into a resonator element (102) having a plurality of carrier resonances (3000) for the carrier frequency of the laser light, wherein adjacent carrier resonances (3000) are spaced apart from one another within a spectral range by a free spectral range (FSR). The method further includes modulating the intensity and / or phase of the portion of the laser light coupled into the resonator element (102) with a first modulation frequency (1001) and a second modulation frequency (1002) to generate, for each carrier resonance (3000), at least two sideband resonances (3001) spaced from the carrier resonance (3000) by the first modulation frequency (1001) and at least two sideband resonances (3002) spaced from the carrier resonance (3000) by the second modulation frequency (1002), wherein the first modulation frequency (1001) and the second modulation frequency (1002) are integer multiples of the free spectral range and are different from each other. The method further includes tuning the carrier frequency of the laser light at a predetermined tuning speed and measuring the intensity of the laser light transmitted and / or reflected by the resonator element (102) while tuning the carrier frequency. Furthermore, the method includes measuring a tuning time elapsed in tuning the carrier frequency across four adjacent sideband resonances (3001, 3002), the tuning time corresponding to the time required to change the tunable carrier frequency from a value corresponding to the first of the four sideband resonances to the last.The method further includes determining the spacing between multiple carrier resonances (3000) within the spectral range using the measured intensity of the laser light transmitted and / or reflected by the resonator element (102), the first modulation frequency (1001), the second modulation frequency (1002), and the tuning time measured when tuning the carrier frequency across four adjacent sideband resonances (3001, 3002).

The utility model discloses a cutting and developing device for steel pipe processing, include: the base plate, the outer wall fixedly connected with the guiding device and the flattening device of base plate top, the inner wall sliding connection has cutting device of guiding device, the utility model relates to steel pipe cutting and developing technical field, this guiding device and flattening device, through fixed plate, threaded rod and the resistance board form "screw thread adjustment and clamping fixed " structure, and the operator can accurately control the resistance board spacing through rotating threaded rod, firmly fixed in the mounting hole with flame cutting nozzle, ensure that the flame nozzle always aligns the bus direction of steel pipe, simultaneously, the MSE-V-ONE laser doppler velocimetry sensor real -time monitoring steel pipe moving speed and position, not only can judge whether the steel pipe reaches the cutting area through the reflected laser intensity, but also can feed back the speed signal to the PLC controller, and dynamically match the gas supply amount of flame cutting nozzle and the conveying speed of steel pipe.

The invention relates to the technical field of power grid operation, and provides a power grid operation safety distance accurate sensing device and method in a non-fixed scene, and the device comprises a hardware device and terminal software which is in communication connection with the hardware device. The hardware device is integrated and deployed on a movable support or a holder, and comprises a laser radar sensor which is used for rapidly scanning a power grid operation scene and obtaining three-dimensional point cloud data including three-dimensional coordinates, laser intensity and echo information; the high-definition visible light camera is approximately parallel to the optical axis of the laser radar sensor and is used for collecting real-time video images of the operation scene; an AI visual analysis module and a point cloud processing unit are arranged in the embedded processor; and the terminal software is deployed on the edge computing equipment or the background server and is used for receiving and processing the data from the hardware device. According to the invention, the safe distance can be accurately sensed.

A method for manufacturing a vehicle crash pad includes heating a skin layer using a heater, attaching a cushion layer to the skin layer, placing a lower mold and an upper mold relative to a fabric including the skin layer and the cushion layer, forming a molded member on the lower mold, vacuum molding. The upper mold is lowered to perform the vacuum molding. The method further includes a laser processing of the fabric and molded member using a processing system, where a sensor senses the fabric and molded member, and based on sensed data, a through-hole is defined by adjusting the intensity of a laser's light irradiated to the fabric and molded member.

A device includes a grouping of N qubits, where N is equal to two or more, and a coherent light source configured to, given selected values for a set of parameters of at least a first and a second laser pulse, the parameters selected from a relative phase shift, a laser frequency, a laser intensity, and a pulse duration: apply at least the first and second laser pulses to all qubits within the grouping of N qubits, thereby coupling a non-interacting quantum state |1 to an interacting excited state |r, such that each qubit that begins in quantum state |1 returns to the state |1 upon completion of the at least first and second laser pulses, and such that qubits in the grouping are mutually blockaded.

The present invention relates to the field of laser cutting control technology, and in particular to a laser processing method, device, equipment and system for metal workpieces. The method calculates the benchmark cutting speed and laser power range of the metal workpiece to be processed from the historical cutting data of the processed workpiece that has been processed. The low processing quality of the current workpiece can be effectively quantified based on the distribution volatility and degree of change of the scattered laser intensity. The probability of metal overheating is further obtained based on the surface temperature of the workpiece. Furthermore, the direction of laser power adjustment in the current state can be determined based on the probability of metal overheating, and the power adjustment amount obtained in combination with the low processing quality can realize adaptive adjustment of the power of the laser cutting process. The present invention ensures the cutting quality of the metal workpiece by monitoring the quality status of the metal workpiece in the laser cutting process in real time and adaptively adjusting the laser cutting parameters according to the quality status.

The invention belongs to the technical field of optical fiber device preparation and sensing, and discloses a honeycomb disc spring type sensing structure and a processing and using method. The polymer spring structure integrally manufactured on the end face of the optical fiber based on the two-photon polymerization 3D printing technology provides a sensing basis for high-precision micro stress detection. The polymer probe with the width smaller than 10 microns realizes the stress detection function of a micro-nano region, and the photocuring processing precision of the structure can be realized by adjusting a series of parameters, such as laser intensity, scanning speed and cutting layering gaps. Experimental results show that the sensing structure can realize high-sensitivity microstress or strain sensing demodulation in a range of 100 mu epsilon to 300 mu epsilon, keeps the structure stable and realizes repeated detection. According to the method, sensing structures suitable for various micro stress and strain ranges can be manufactured by adjusting structural parameters according to user requirements.

The application relates to a laser speckle image denoising method and device, which combines the complementary advantages of a laser intensity image and a laser phase image, extracts and fuses a contour feature map of a laser speckle image and a curvature feature map and a normal vector feature map of a laser phase image, provides a neural network with abundant geometric context, and further adds geometric feature constraints in the neural network to form a hierarchical system. The synergistic effect of the geometric constraints enables the denoising model to accurately maintain the edge contour, local surface morphology, surface orientation and overall topological structure of the image when removing speckle noise, significantly improves the geometric structure integrity of the denoised image, and effectively solves the problem that denoising and structure preservation are difficult to balance and diagnostic information is lost in the background technology. The application provides a more reliable and accurate solution for medical imaging application scenarios, and has significant technical progress and application value.

The present invention relates to the field of image processing technology, and provides a method and system for calibrating the extrinsic parameters of a target-free laser event camera based on information distance. The method comprises: generating a cumulative event image and a laser intensity image, and performing image enhancement processing; performing preliminary optimization on the enhanced cumulative event image and the laser intensity image by minimizing the reprojection error to obtain initial extrinsic parameters; obtaining the probability density function of the laser point cloud intensity, event pixel value and their joint distribution by kernel density estimation, and calculating the normalized information distance based on the information entropy principle; using a rotation and translation extrinsic parameter decoupling optimization method based on sequential quadratic programming, optimizing the initial extrinsic parameters by normalized information distance constraints to obtain the optimal extrinsic parameters. The present invention realizes robust calibration of laser radars and event cameras without the need for targets and manual initial value setting, and can stably, smoothly and accurately achieve extrinsic parameter optimization solutions.

There is provided a method of forming a bismuth-containing gallium oxide-based semiconductor film on a base material by a pulse laser deposition method using a target containing gallium oxide and bismuth oxide. In the method, the temperature of the base material is set to 650° C. to 1,000° C., and the laser intensity is set to 1.0 J / cm2 to 10.0 J / cm2. The bismuth-containing gallium oxide-based semiconductor film of the present disclosure has a proportion of the number of atoms of bismuth of 0.50 at % to 10.00 at % with respect to the total of the numbers of atoms of bismuth and gallium and has a β-gallia structure. The bismuth-containing gallium oxide-based semiconductor component of the present disclosure has a base material and the bismuth-containing gallium oxide-based semiconductor film that is laminated on the base material.

The invention discloses an NV color center excitation laser adjusting method, a medium, a control device and measurement equipment, and relates to the technical field of quantum measurement. The method is used for the NV color center excitation laser debugging system. The system comprises a laser used for emitting target laser, at least two adjusting lenses used for expanding the target laser, and a focusing lens used for focusing the expanded target laser to generate laser spots. The method comprises the following steps: adjusting an adjusting lens according to a laser spot, so that the laser spot is matched with a laser incident surface of a target diamond; the adjusting lens is adjusted according to the fluorescence brightness generated when the NV color center in the target diamond is excited by the laser spot, so that the area of the laser spot is reduced, the position of the laser spot on the laser incident plane is adjusted, and the fluorescence brightness meets the target excitation requirement. Therefore, the NV color center position can be quickly positioned, the concentration ratio of the laser is enhanced, the laser intensity and the effective utilization rate are improved, and the accuracy and the sensitivity of measuring equipment are improved.

The present invention discloses a downhole oil casing laser perforating device, which belongs to the technical field of oil drilling. The device comprises the following steps: obtaining perforating parameter state data, perforating environment state data, beam quality influence data and current perforating state data; generating a perforating parameter state index and a perforating environment state index based on the perforating parameter state data and the perforating environment state data, and obtaining a perforating basic coefficient based on the perforating parameter state index and the perforating environment state index; generating a beam quality influence factor based on the beam quality influence data, and obtaining a perforating synergy coefficient of a current perforating depth and a beam linear velocity in the current perforating state data under the condition of the current beam quality influence factor; constructing a laser intensity adjustment model based on the synergy of the current perforating depth and the beam linear velocity, the perforating basic coefficient and the current laser intensity to generate a laser intensity adjustment value; the present invention can realize deep penetration perforation of oil casing by dynamically regulating laser parameters.

This invention discloses a system and method for detecting water dynamics information based on laser intensity modulation, comprising: a signal sensing and modulation transmission module, an optical signal receiving and conversion module, and a data acquisition and processing module connected in sequence; the signal sensing and modulation transmission module is used to sense water dynamic parameters and generate corresponding electrical signals, thereby modulating the output light intensity of the laser transmitter so that the intensity of the output laser carries water dynamics information; the optical signal receiving and conversion module is used to receive the modulated laser signal and restore it to an electrical signal; the data acquisition and processing module is used to acquire, process, and analyze the electrical signal to extract the water dynamics information. This invention, by adopting a simplified technical approach of laser intensity modulation and direct detection, replaces the traditional complex frequency modulation system, successfully solving the long-standing core problems in the field of water dynamics detection: high equipment cost, system complexity, and difficulty in widespread adoption.

This invention proposes a high-precision method for measuring airflow thrust by extracting the Doppler frequency shift difference from the scanning absorption spectrum. A tunable laser performs forward and reverse scanning of the absorption spectrum. The laser wavenumber scanning waveform is symmetrical about the lowest wavenumber point. The laser beam is split into two beams, which cross the longitudinal section of the airflow center. The target gas absorption spectrum curve is obtained by measuring the laser intensity curve. The sum of the central wavenumbers of the absorption spectrum in both forward and reverse scans along the airflow path is calculated, as is the sum of the central wavenumbers in both forward and reverse scans against the airflow path. The Doppler frequency shift difference is extracted from the difference between the two sums of central wavenumbers, thus measuring the airflow velocity. The static temperature of the airflow is obtained using colorimetric thermometry, and the static pressure of the airflow is obtained using a nonlinear fitting method. The thrust is calculated by combining the airflow velocity, static temperature, and static pressure. This invention achieves airflow velocity measurement resistant to temporal noise interference and has significant application prospects in the field of integrated space-ground thrust measurement for engines.

To provide an optical integrated laser element capable of reducing the occurrence of a mode hop while increasing the intensity of an output laser beam.SOLUTION: The optical integrated laser element includes a distributed feedback laser part, a semiconductor optical amplification part, and a high reflection film. The distributed feedback laser portion includes a diffraction grating and a first optical waveguide. The first optical waveguide is provided along the diffraction grating and has a gain. The semiconductor optical amplifier unit is provided on the substrate, is provided on a first side of the distributed-feedback laser unit, is optically connected to the first optical waveguide, has a gain, and includes a second optical waveguide having a width wider than a width of the first optical waveguide. The high reflection film is provided on an end surface on a second side opposite to the first side of the distributed feedback laser portion. The distributed feedback laser portion and the semiconductor optical amplification portion are integrated on the substrate. The length of the first optical waveguide in the optical waveguide direction is 1000 μm or less, and the length of the second optical waveguide in the optical waveguide direction is 1.5 times or more and 7 times or less the length of the first optical waveguide in the optical waveguide direction.SELECTED DRAWING: Figure 1

The application discloses a kind of based on vacuum environment laser intensity detection device and detection method, including cavity, photoelectric sensor and detector;The periphery of cavity is provided with at least two through holes and one air extraction hole;Wherein, two through holes form channel for laser transmission between them, and two through holes can be communicated with external device by pipeline;Air extraction hole is connected with external vacuumizing equipment;Photoelectric sensor is movably installed in cavity, and can be switched to the middle part of channel, to cut off the measurement state of optical path or switch to the idle state of channel optical path unblocked;Detector is electrically connected with photoelectric sensor.The application relates to the technical field of laser intensity detection, by the above setting, the intensity of laser formed under vacuum environment is detected by switching the position state of photoelectric sensor, without breaking vacuum or changing optical path, to realize the detection of light intensity without interfering with the original optical path in the device.

The application relates to the technical field of ultrasonic sensors and discloses a kind of optical fiber end face integrated microcavity acoustic wave sensors, including seven-core optical fiber, two light propagation waveguides, coupling waveguide, support assembly, microdisk, light emitter and photodetector, the end face of seven-core optical fiber is provided with two light propagation waveguides, coupling waveguide is arranged between two light propagation waveguides, the end face of seven-core optical fiber is provided with support assembly, the top of support assembly is provided with microdisk, first fiber core and second fiber core are connected with external light emitter and photodetector respectively;Light emitter outputs laser wavelength lock at the linear slope of microdisk resonance peak, through ultrasonic wave acting on microdisk, vibration changes its radius and effective refractive index, causes resonance peak drift and output laser intensity change, and then detects ultrasonic wave;Compared with the prior art, the application detects ultrasonic wave by the method of microdisk resonance and laser lock sideband, and can effectively avoid the problem of electromagnetic interference by using optical principle.

The present application relates to a kind of background guided schlieren temperature field reconstruction method and device combined with laser absorption spectrum, the method includes the following steps: step one, build the measuring device of background guided schlieren tomography, complete laser collimator alignment;Step two, kHz sawtooth wave signal is generated using function signal generator, the output wavelength range of tuning laser is scanned repeatedly the absorption spectral line of each gas component in flame;Step three, using multi-camera acquisition a group of schlieren image when temperature and density are uniformly distributed in the measurement region, and the schlieren image of the measurement region is synchronously collected when the temperature and density to be measured are non-uniformly distributed;Step four, move background pattern board through time-sharing mechanism;Step five, acquisition multi-wavelength laser scanning signal;Step six, according to laser intensity, Voigt line type fitting is carried out;Step seven, inversion operation is carried out, and the three-dimensional temperature field of measurement region is obtained.The method can obtain higher resolution three-dimensional temperature field distribution.

The invention discloses a laser radar full-waveform intensity correction method based on spatial-temporal feature decoupling, and the method comprises the following steps: (1) obtaining laser radar data, and synchronously carrying out the preprocessing of original full-waveform data; (2) constructing a waveform distortion model, and decomposing the full waveform data into a target component and a system noise component; (3) dividing the target component into a plurality of time sequences, and extracting time features and space features; (4) constructing a dynamic convolutional strength compensation network, and accurately predicting a distance compensation coefficient and a material compensation coefficient based on the spatial-temporal characteristics obtained in the step (3); and (5) enabling the compensation coefficient obtained in the step (4) to act on the laser intensity of the original target component to obtain corrected full-waveform intensity data. According to the method, the target reflection component and the system noise component are separated by establishing the waveform distortion model, and the distance compensation coefficient and the material compensation coefficient are accurately predicted by using the dynamic convolution intensity compensation network, so that high-precision correction of the laser radar full-waveform intensity is realized.

The invention relates to a double-pulse modulation long-distance distributed optical fiber temperature sensing system which comprises a laser, laser output by the laser is transmitted to a grating and a first-stage laser modulator through a beam splitter, laser output by the first-stage laser modulator is transmitted to one port of a circulator through a first laser amplifier, and laser output by the second-stage laser modulator is transmitted to the other port of the circulator through a second laser amplifier. A lower port of the circulator is connected with the sensing optical fiber, a second lower port of the circulator is connected with the input end of the second laser amplifier, the grating and the output end of the second laser amplifier are connected with the signal processing module, and a second-level laser modulator is further arranged between the first-level laser modulator and the first laser amplifier. The laser pulse width output by the first-stage laser modulator is larger than that output by the second-stage laser modulator, and the first-stage laser modulator has laser intensity gain of at least one decibel. The dipulse modulation long-distance distributed optical fiber temperature sensing system provided by the invention has a relatively long detection distance under the condition that the resolution ratio is not reduced.