30 results about "Pulse amplifiers" patented technology

The invention relates to a method for detecting a marine corrosion primary process, which comprises the following steps of: constructing three vacuum chambers and connecting the three vacuum chambers by using vacuum pipelines to form a detection system; ultrafast femtosecond laser with the repetition frequency being 1 kHz, the single pulse energy being 6 mJ, the pulse width being 35 fs and the central wavelength being 800 nm is generated through a pulse amplifier; one beam of 2mJ enters a vacuum chamber pipeline to be transmitted as a pulse light beam for detection in the original process of ocean corrosion, the other beam of 4mJ is transmitted outside the vacuum chamber to be used as a pump pulse light beam, and 400 nm pump pulse laser is generated through frequency doubling of a BBO crystal; the pump light beam and the detection light beam are incident on a sample of a sample mechanism in the third vacuum chamber, then the pump light beam is blocked, and only the detection light beam is incident on the sample; xUV light beams reflected from the sample are subjected to spectral dispersion and then enter a CCD detector, and the dynamic response of the sample after being excited by the pump light is monitored by measuring the transmissivity, reflectivity or absorption change of the surface of the sample.

The invention discloses a broadband spectrum all-fiber femtosecond laser system based on chirped pulse amplification and an adjusting method of the broadband spectrum all-fiber femtosecond laser system. The broadband spectrum all-fiber femtosecond laser system comprises a broadband spectrum dissipative soliton mode-locked fiber laser and an all-fiber chirped pulse amplifier which are connected. The broadband spectrum dissipative soliton mode-locked fiber laser comprises a first pumping source, a first wavelength division multiplexer, a first gain fiber, a first polarization controller, a polarization dependent isolator, a second polarization controller and a coupler. The all-fiber chirped pulse amplifier comprises a first polarization independent isolator, a dispersion compensation fiber, a second wavelength division multiplexer, a second gain fiber, a third wavelength division multiplexer, a single-mode fiber, a second polarization independent isolator, a second pumping source and a third pumping source. The system realizes the wide spectrum characteristic through the optical fiber length adjusting module, the spectrum adjusting module and the fine adjusting module. The device is simple in structure, wide in application scene, not prone to pulse distortion, wide in spectrum and high in anti-interference capacity.

A large-mode-field photonic crystal fiber amplifier and its fabrication method are disclosed. The amplifier comprises a bundled cladding fiber, a mode-matched solid photonic crystal fiber, a rare-earth-doped silica gain photonic crystal fiber, and an output fiber connected in sequence. This large-mode-field photonic crystal fiber amplifier can be readily used in all-fiber pulsed lasers to achieve high beam quality and high-energy output. The output fiber has a flexible bending mechanism and requires no additional processing of the output end face, thus improving the practicality of fiber pulsed lasers.

The application discloses a mass spectrometer for measuring a low-isotope-content sample and belongs to the technical field of mass spectrometers. The mass spectrometer comprises a receiving device and a signal processing unit. The receiving device comprises a vacuum cavity, a metal target, a vacuum plastic flash body, a high-voltage electrode plate, a vacuum glass window, a photomultiplier tube and a photomultiplier tube cover. The signal processing unit comprises a high-voltage stabilizer and a pulse amplifier. The application converts ions into secondary electrons through the metal target, provides voltage for the metal target and the high-voltage electrode plate by the high-voltage stabilizer to form a high-intensity electric field, accelerates the secondary electrons to bombard the vacuum plastic flash body to generate an optical signal, receives and converts the optical signal into a pulse signal by the photomultiplier tube through the vacuum glass window, and finally performs shaping, amplification and conversion processing on the pulse signal by the pulse amplifier. The application does not need to rely on imported super-high resistance resistors, realizes the localization of the receiving device of the mass spectrometer, and has the advantages of high signal conversion efficiency, strong anti-interference capability, stable and reliable measurement and the like.

The utility model discloses a silicon controlled rectifier trigger power supply system for a fused salt heating power supply, relates to the field of power supplies, and solves the problems of large size, high cost and the like caused by realizing the fused salt heating power supply through a transformer. The frequency and duty ratio are changed through the signal source, the power supply voltage of the pulse amplifier to the driving board is adjusted, the output current and frequency of the pulse amplifier are adjustable, the requirements of different occasions are met, the beam splitting plate is divided into multiple paths of pulses through the controller, the synchronism of multiple paths of optical signals is guaranteed, and the light splitting efficiency is improved. Therefore, the conduction consistency of the silicon controlled rectifiers in the series valve group is greatly improved, the probability that few silicon controlled rectifier modules in the series valve are damaged due to bearing over-high voltage for a long time is reduced, a transformer is not needed, the size is small, the weight is light, and the problems of large size, high cost and the like caused by realizing a molten salt heating power supply through the transformer are solved.

The invention discloses a 2-micron short-period laser amplifier based on a thulium-doped positive dispersion fluorotellurite optical fiber, which can solve the problem that a negative dispersion thulium-doped optical fiber is not suitable for performing gain management nonlinear amplification on a 2-micron pulse, and can obtain a pulse width lt. 50 fs, and single pulse energy gt; the femtosecond laser output device has the advantages of being full-fibrillated and compact in structure. The 2-micron femtosecond seed source is femtosecond pulse laser of a 2-micron wave band generated based on nonlinear amplification loop mirror mode locking; the chirped pulse amplifier is used for obtaining sub-picosecond 1.9 mu m femtosecond laser output with the average power greater than or equal to 1W; the optical fiber GMN amplifier is used for obtaining a few-period femtosecond pulse; the high-power optical fiber pulse compressor is a hollow-core optical fiber and is used for carrying out accurate dispersion compensation and high-quality pulse compression.

This invention discloses a device for locating vibration events on power transmission lines. The device includes a pulsed laser module, an optical pulse amplifier, an optical fiber circulator, an optical fiber polarizer, a sensing optical fiber, a photodetector, a data acquisition card, and a data processing and control unit. It utilizes the optical fiber inherent in the power transmission line or a separately laid optical fiber as the sensing fiber. While the optical pulse propagates in the sensing fiber, it generates a Rayleigh scattering signal. Vibration events on the power transmission line disturb the polarization state and phase of the Rayleigh scattering signal, resulting in a significant difference in noise convergence in the obtained optical time-domain reflectometry curve before and after the location of the induced vibration on the sensing fiber. Therefore, the location is determined by identifying the convergence start point. This device is suitable for locating external vibration sources on quasi-static power transmission lines and has advantages such as long monitoring coverage distance, high positioning accuracy, and low false alarm rate.

The utility model discloses a kind of distributed optical fiber temperature detection systems, including the sensing optical fiber being laid along the length direction of low temperature pipeline;The end of the sensing optical fiber is provided with laser light source and optical signal pulse amplifier, the laser light emitted by the laser light source enters the sensing optical fiber after amplification by the optical signal pulse amplifier, and raman scattering occurs at each position of the sensing optical fiber;The end of the sensing optical fiber is also provided with data acquisition module, APD photoelectric conversion module and wave division multiplexer, laser scattering in the sensing optical fiber will form the echo signal of different wavelength stokes light and anti-stokes light, the echo signal of the sensing optical fiber is converted after passing through the wave division multiplexer and the APD photoelectric conversion module, enters the data acquisition module, and the data acquisition module obtains the light intensity signal of at least two beams of light, based on the principle that light intensity is different under different temperatures, the temperature condition of reflection point is obtained by analyzing light intensity change.

The utility model relates to four program femtosecond laser compressor, through the light of first time through the compressor output is injected into the compressor for many times, incident chirp pulse is along the compressor light path and is emitted four times, total transmission grating 8 times, finally through the output mirror output completes compression output, make the number of times of light beam through grating increase to 16 times, make the same grating aperture and grating spacing compressor dispersion quantity turn 4 times, adapt to bigger spread width or bigger bandwidth chirp pulse amplifier, many times repeat, expand the use number of times of compression grating, obtain bigger compression under the condition that the grating spacing of compressor is unchangeable, can be compatible with bigger spread width of chirp pulse amplifier, solve the problem of design limit of chirp pulse amplifier, promote femtosecond laser output single pulse energy.

The invention belongs to the field of laser emission devices, and provides a system and a method for adjusting and compensating high-order dispersion through broadening-compression coordination, and the method comprises the steps: calculating second-order dispersion and third-order dispersion introduced by a pulse amplifier; the introduced third-order dispersion is adjusted by changing the grating incidence angle in the pulse stretcher, so that the introduced third-order dispersion is counteracted with the total third-order dispersion of the system; according to the second-order dispersion change generated after the angle of the pulse stretcher is adjusted, a second-order dispersion value required to be provided by the pulse compressor is calculated, and the effective distance of the grating pair is adjusted for accurate compensation; and the angle of the pulse stretcher is corrected again according to the third-order dispersion feedback adjusted by the pulse compressor, and the steps are repeated until the total second-order dispersion and the third-order dispersion of the system approach to zero, so that near-transformation limit compression is realized. By adjusting the grating incident angle of the stretcher and the grating effective distance of the compressor, synchronous compensation of second-order and third-order dispersion in the ultrafast laser system is realized, and pulse output close to the transformation limit is obtained.

The present invention provides an ultra-compact high extinction ratio laser pulse cleaning device and method. The device comprises: a laser oscillator, a pulse stretcher, a pulse amplifier, a first broadband high-reflection mirror, a first broadband polarizer, an electro-optical switch, a second broadband polarizer, a second broadband high-reflection mirror and a third broadband high-reflection mirror; wherein the first broadband polarizer and the second broadband polarizer are placed orthogonally to each other; the laser oscillator generates a seed laser, which is sequentially pulse stretched by the pulse stretcher and pulse amplified by the pulse amplifier; the amplified laser pulse sequentially passes through the first broadband high-reflection mirror, the first broadband polarizer, the electro-optical switch, and the second broadband polarizer to form an incident light path; the laser pulse emitted after passing through the second broadband polarizer sequentially passes through the second broadband high-reflection mirror, the second broadband polarizer, the electro-optical switch, the first broadband polarizer and the third broadband high-reflection mirror to form a reflected light path.

The application belongs to the field of laser emitting devices, and provides a system and method for compensating high-order dispersion through cooperative adjustment of stretching and compression, calculating second-order dispersion and third-order dispersion introduced by a pulse amplifier; adjusting the introduced third-order dispersion by changing the grating incident angle in a pulse stretcher, so that the third-order dispersion is offset with the total third-order dispersion of the system; calculating the second-order dispersion value required to be provided by the pulse compressor according to the second-order dispersion change generated after the angle adjustment of the pulse stretcher, and accurately compensating by adjusting the effective distance of the grating pair; feeding back the third-order dispersion of the pulse compressor after adjustment to correct the angle of the pulse stretcher again, and repeating the above steps until the total second-order dispersion and third-order dispersion of the system tend to be zero, so as to realize near transform limit compression. The application adjusts the grating incident angle of the stretcher and the effective distance of the grating of the compressor, so that the second-order dispersion and third-order dispersion in the ultrafast laser system are simultaneously compensated, and near transform limit pulse output is obtained.

The invention discloses a voltage generating circuit and a long sequence pulse output unevenness adjusting method thereof.The voltage generating circuit comprises an interface circuit, an FPGA, a memory, a D / A converter, an operational amplifier and a power conversion circuit, the interface circuit is used for converting various external control signal levels into signals which can be recognized by the FPGA and inputting the signals into the FPGA, and the interface circuit is used for converting various external control signal levels into signals which can be recognized by the FPGA; the FPGA collects radio frequency signal synchronization pulses from input signals and detects the radio frequency signal synchronization pulses, and is used for realizing segmented statistics of pulse sequences, controlling the D / A converter to dynamically output analog signals according to grid voltage calculation parameters preset in the memory, outputting grid voltage after the analog signals pass through the operational amplifier, and realizing dynamic adjustment of the grid voltage. Therefore, the purpose of long sequence pulse high-power output unevenness adjustment is achieved, an L wave band radio frequency pulse amplifier with the output power being about 700 W is achieved, sequence unevenness adjustment of continuous 770 pulses is achieved, and the sequence unevenness is controlled to be smaller than or equal to 1 dB.

According to the four-way femtosecond laser compressor and the method, light output through the compressor for the first time is injected into the compressor for multiple times, incident chirped pulses enter and exit for four times along the light path of the compressor, the incident chirped pulses pass through a transmission grating for eight times in total, and finally the incident chirped pulses are output through an output reflector to complete compression output; the number of times that a light beam passes through the grating is increased to 16, so that the dispersion amount of a compressor with the same grating caliber and grating spacing is increased by 4 times, and the chirped pulse amplifier with larger spreading amount or larger bandwidth is adapted; according to the femtosecond laser, the use frequency of the compression grating is expanded repeatedly, and a larger compression amount is obtained under the condition that the space between the compression grating is not changed, so that the larger broadening amount of the chirped pulse amplifier can be compatible, the problem of design limitation of the chirped pulse amplifier is solved, and the output monopulse energy of the femtosecond laser is improved.

The present invention discloses a high-energy single-frequency pulse amplifier integrating pump and active optical fiber, which relates to the field of pulse laser amplification technology, including: a single-frequency seed source, a modulator, a first integrated structure, a first isolation filter, a second integrated structure, a second isolation filter, a third integrated structure, and an output head; the present invention mainly replaces the traditional transmission optical fiber connection in the manufacturing process by a wavelength division multiplexer and a pump combiner, and directly adopts the two ends of the gain optical fiber for welding, so as to build a high-energy single-frequency pulse amplification structure. The technical solution proposed by the present invention can shorten the system optical fiber by 3.5-6.5 meters, reduce 7 welding points, improve the stimulated Brillouin scattering threshold in the process of high-energy single-frequency pulse amplification, and improve the laser output power and system stability.

The invention provides a phase delay self-compensating vector polarized light parametric chirped pulse amplifier which comprises a narrow-band pulse laser, a broadband pulse laser generating device, a half-wave plate, a polarization beam splitter, a pulse stretcher, a laser mode converter, a first nonlinear crystal, a second nonlinear crystal and a pulse compressor. The phase delay introduced by the second-stage optical parameter chirped pulse amplification to the two orthogonal polarization components of the vector polarization signal light is used for counteracting the dynamic phase delay accumulated in the first-stage optical parameter chirped pulse amplification process. The objective of the invention is to solve the problem of polarization distortion of vector polarized light caused by different accumulated phase delays of all frequency components in the optical parameter chirped pulse amplification process, so that the vector polarized light can obtain broadband high-gain amplification while the initial polarization characteristic of the vector polarized light is kept unchanged. Vector polarized light parametric chirped pulse amplification with high polarization purity and high peak power is realized.

The invention discloses a self-excited oscillation and acoustic vortex ring synergetic fluid enhanced flotation treatment device and a self-excited oscillation and acoustic vortex ring synergetic fluid enhanced flotation treatment method. The device comprises a feeding mechanism, a feeding conveying pipe, a volute pre-rotating mechanism, a stepped ultrasonic strengthening mechanism, a Helmholtz cavity pulsating amplifier and a main body flotation mechanism, wherein the volute pre-rotating mechanism and the stepped ultrasonic strengthening mechanism are sequentially arranged on the feeding conveying pipe in the feeding direction, the Helmholtz cavity pulsating amplifier is arranged on the volute pre-rotating mechanism, and the main body flotation mechanism is connected with the tail end of the feeding conveying pipe. The Helmholtz cavity pulsating amplifier comprises a teardrop type shell, a reducing neck pipe communicated with an amplifier inlet in the upper portion of the teardrop type shell, an auxiliary self-suction air inlet assembly arranged on the periphery of a throat pipe part of the reducing neck pipe, a flow stabilizing assembly arranged in the teardrop type shell and a pressure sensor arranged on the teardrop type shell. The method is particularly suitable for mineral flotation, wastewater air flotation treatment, biological reaction enhancement and other scenes, and accurate generation and efficient collision mineralization of micron-sized bubbles can be achieved by cooperatively regulating and controlling bubble size distribution and the particle-bubble collision dynamic process.

The utility model discloses a material defect detection device based on an ultrasonic transmission reflection method. The material defect detection device comprises an AD sampler (1), a pulse signal source (2), a directional coupler (3), a first ultrasonic probe (4), a test sample (5), a pulse amplifier (6) and a matched load (7), the directional coupler (3) is provided with a first port (8), a second port (9) and a third port (10), the first port (8) is communicated with the third port (10), and the second port (9) only receives part of echo signals of the third port (10), so that the AD sampler (1) is connected with the second port (9), and detection signals from the first ultrasonic probe (4) can be acquired in real time; the AD sampling device (1), the pulse signal source (2) and the directional coupler (3) are integrated in the packaging shell (11), signal connection in the packaging shell (11) is fixed, only the first external port (12) and the second external port (13) are arranged, and two tests of an ultrasonic transmission method and a reflection method can be achieved.

There is described a laser pulse generator, comprising: one or more seed laser sources for generating a plurality of sequentially-timed seed pulses; input optics arranged to direct the plurality of sequentially-timed seed pulses through gain medium; the gain medium configured to be pumped by pump diodes to increase the energy of the pulses; and synchronisation optics arranged to guide the plurality of pulses from the gain medium along respective delay paths to temporally synchronise the pulses at one or more targets. Spatial recombination may also be included. Corresponding methods are described.

An RF pulse amplifying device includes an amplifier configured to amplify a pulsed RF signal, a DC link configured to supply a DC bus voltage, and an energy storage device connected to the DC link. The amplifier has an input for receiving a supply voltage. The input of the amplifier is connected to the DC link through a switched DC / DC converter, which is configured to step down the DC bus voltage, supplied at the converter input, to the supply voltage, applied to the converter output. A control unit is configured to operate the switched DC / DC converter during amplification of the RF pulse to control the supply voltage at a predetermined value.

The present invention discloses a jitter calibration system and method for a superconducting nanowire single photon detector, including an FPGA platform for generating a periodic pulse calibration signal, a radio frequency pulse amplifier, a lithium niobate electro-optic modulator and its bias voltage controller, a 1550nm 3kHz linewidth distributed feedback laser, a programmable optical attenuator, a three-paddle polarization controller, an SNSPD single photon detector, a multi-channel TDC module, and a host computer for processing data. The calibration method is simple and has a low cost. It can calibrate the correction curve of the relationship between the additional jitter of the SNSPD detected photons caused by pulse pile-up and the detection recovery time, and compensate for the additional jitter, effectively solving the problem of jitter deterioration of the SNSPD at high counting rates in high-speed detection applications.

The present invention relates to a cascadable low-temperature and low-noise current pulse amplifier. The pulse amplifier includes an nTron device, an input coupling circuit, an output coupling circuit, and a bias circuit. The current signal to be detected is coupled to the gate terminal of the nTron through the input coupling circuit. The drain terminal of the nTron is connected to the signal output port V_out through the output coupling circuit. The bias current of the nTron is connected to the nTron through the bias circuit. The signal output port directly outputs the signal or is connected to the input coupling circuit in the next-stage pulse amplifier. The cascadable low-temperature and low-noise current pulse amplifier of the present invention operates in an extremely low-temperature environment, hardly introduces additional noise, amplifies weak current pulse signals to a certain extent, and improves the signal-to-noise ratio of weak current pulse signals. Moreover, the system has scalability and can achieve different amplification requirements through cascading.

The present invention discloses a method and a system for pulsing a particle beam. The method includes: Step 1, sending the beam cutting signal that has been received, amplified, and shaped into a pulse signal to a frequency divider, and forming square wave pulse signals with different frequencies in the frequency divider; Step 2, the square wave pulse signal forms two separate pulses, namely a pulse on signal and a pulse off signal. The time interval between the two pulse signals is the pulse width, and the pulse width is continuously adjustable. Then, the two signals are respectively sent to two pulse delay circuits as delay start pulses; Step 3, based on the pulse sequence generated by the pulse delay circuit, generating a narrow pulse of 70V@20ns and driving the pulse transformer in the pulse power amplifier; Step 4, the pulse transformer generates high-frequency high-voltage pulses of ±450V and sends them to the deflection plates, where a ±450V DC power supply is output to the pulse amplifier.

The invention discloses a multi-channel synchronous pulse generator based on discrete devices, which comprises a synchronous trigger control module and M synchronous pulse generation circuits, and is characterized in that the synchronous trigger control module is used for generating a trigger signal; the M synchronous pulse generation circuits are used for respectively generating M synchronous pulses with the same channel pulse width according to the received trigger signal and outputting the M synchronous pulses, and each synchronous pulse generation circuit comprises a pulse generation module, a pulse shaping module, a pulse amplification module and an output interface, in the pulse generation module, an RC circuit is adopted in front of and behind a pulse generation chip respectively to achieve pulse delay and pulse width adjustment, and consistent output of multi-channel pulse signals is achieved. The synchronous pulse generator is designed and built by using a discrete logic device, the pulse delay and the pulse width are adjusted at high precision by adjusting the resistance value of the adjustable resistor in the RC circuit, and the consistent output of multi-channel pulse signals is realized.

------ Pulse generation system for pulsed working fluid supply, and washing machine comprising such a system The invention relates to a pulse generation system (1) for pulsed working fluid supply, comprising a pipeline (2), a pressurized working fluid source (3) connected to the pipeline (2), an inclined seat valve (4) connected to the pipeline, a pressurized control fluid source (5), a pressure regulator (6) connected to the pressurized control fluid source (5), a three-way, two-position control valve (7) connected to the pressure regulator (6) and the inclined seat valve (4) and configured to control the inclined seat valve (4), and a control device (8) configured to control the pressure regulator (6) according to desired pulse amplitudes and to control the control valve (7) according to desired pulse frequencies.The invention also relates to a washing machine (10) comprising a system (1). Figure to be published: Figure 1.

Delivery systems comprising pulse producer and first pulse supplier including first optical fiber path, first pulse amplifier and first delivering end. Pulse producer produces first low-power laser pulse having power predefined to avoid or minimize deformation of first low-power laser pulse. First pulse amplifier amplifies first low-power laser pulse to produce first high-power laser pulse having power predefined to operate first end-component connectable with first delivering end. First optical fiber path has initial section to convey first low-power laser pulse from pulse producer to first pulse amplifier, and final section to convey first high-power laser pulse from first pulse amplifier to first delivering end. First pulse amplifier is arranged at a position along first optical fiber path corresponding to distal position relative to pulse producer or proximal position relative to first delivering end. Methods and computer programs suitable for being performed by / at such delivery systems.

This invention discloses a broadband all-fiber femtosecond laser system based on chirped pulse amplification and its adjustment method. The broadband all-fiber femtosecond laser system includes a broadband dissipative soliton mode-locked fiber laser and an all-fiber chirped pulse amplifier connected together. The broadband dissipative soliton mode-locked fiber laser includes a first pump source, a first wavelength division multiplexer, a first gain fiber, a first polarization controller, a polarization-dependent isolator, a second polarization controller, and a coupler. The all-fiber chirped pulse amplifier includes a first polarization-independent isolator, a dispersion-compensating fiber, a second wavelength division multiplexer, a second gain fiber, a third wavelength division multiplexer, a single-mode fiber, a second polarization-independent isolator, a second pump source, and a third pump source. The system achieves broadband characteristics through fiber length adjustment, spectral adjustment, and micro-adjustment modules. This invention has a simple structure, wide application scenarios, pulse distortion resistance, broad spectrum, and strong anti-interference capability.

The invention discloses a temperature measurement system and method for a high-power pulse amplifier, and solves the problems that the high-power pulse amplifier is large in gate leakage current, affects the gate voltage, affects the drain current through a trap effect, and enables the temperature not to be a single variable of the drain current. The temperature change is difficult to accurately reflect by measuring the drain current; the influence of the gate leakage current on the gate voltage is reduced by changing the series resistance and the ground parallel capacitance on the gate modulation circuit, so that the temperature becomes the unique variable of the drain current change, and then the magnitude of the drain current of the pulse power amplifier is measured through the current clamp. And calculating the surface temperature of the tube core of the high-power pulse amplifier according to the relationship between the instantaneous drain current and the surface temperature of the tube core of the high-power pulse amplifier. The method solves the problem that the surface temperature of the tube core of the high-power pulse amplifier is influenced by multivariable in a traditional electrical temperature measurement method, and has the advantages of rapid temperature measurement and capability of being applied to temperature measurement in different temperature environments.

Ultrasonic sensor device comprising: a driver unit (10) for providing a transmission pulse to a transducer that transmits an ultrasonic wave and receives an echo of the ultrasonic wave; an amplifier (20) for amplifying an electrical signal for the echo; an analog-to-digital converter (30) for converting the amplified electrical signal into an original digital signal; a signal processor (40) for performing envelope extraction processing on the original digital signal to generate an extracted signal; and a control unit (50) for outputting a distance signal related to an external object based on the original digital signal and the extracted signal, wherein the control unit comprises: a test frequency generator (51) for applying a test frequency signal to the converter; an excitation frequency measuring unit (52) for measuring an excitation frequency generated in the transducer; and an optimal frequency calculator (53) for calculating an optimal frequency using the excitation frequency, where the excitation frequency is the frequency of an excitation that oscillates freely in an excitation mode range between a transmission mode and a reception mode of the transducer, and wherein the optimal frequency is an intermediate value between the excitation frequency and an anti-resonance frequency.

The invention discloses a distributed optical fiber vibration monitoring device based on logarithm transformation. Comprising a narrow linewidth laser, an acousto-optic modulator, an optical pulse amplifier, an optical fiber circulator, a verification optical fiber unit, a balanced photoelectric detector, a band-pass filter, a low-noise amplifier, a logarithmic detector, a data acquisition and processing module, an industrial personal computer, a first optical fiber coupler, a second optical fiber coupler and an optical fiber interface. A radio frequency signal is converted into a voltage signal in a logarithmic detection mode, so that the requirements of a subsequent data acquisition and processing module on a sampling rate and high-speed data processing are reduced, and a vibration event along a sensing optical fiber is identified and positioned through gradual difference operation of a time domain logarithmic signal and a normalized threshold calibration algorithm. The distributed optical fiber vibration monitoring device provided by the invention is simple in structure, and the performance requirements of a device based on a traditional scheme on system hardware such as an acousto-optic modulator and a data acquisition and processing module can be greatly reduced.