224 results about "Erbium doped fibre amplifier" patented technology

An apparatus, method and associated fiber-laser architectures for high-power pulsed operation and pumping wavelength-conversion devices. Some embodiments generate blue laser light by frequency quadrupling infrared (IR) light from Tm-doped gain fiber using non-linear wavelength conversion. Some embodiments use a fiber MOPA configuration to amplify a seed signal from a semiconductor laser or ring fiber laser. Some embodiments use the frequency-quadrupled blue light for underwater communications, imaging, and / or object and anomaly detection. Some embodiments amplitude modulate the IR seed signal to encode communication data sent to or from a submarine once the modulated light has its wavelength quartered. Other embodiments transmit blue-light pulses in a scanned pattern and detect scattered light to measure distances to objects in a raster-scanned underwater volume, which in turn are used to generate a data structure representing a three-dimensional rendition of the underwater scene being imaged for viewing by a person or for other software analysis.

The invention relates to the technical field of fiber sensing, and especially to a pre-pumped pulse and Gray code based BOTDA instrument. The BOTDA instrument comprises a narrow-linewidth semiconductor sensor, a coupler, a first erbium doped fiber amplifier, a first polarization controller, a single sideband modulator, a microwave source, an optical isolator, a sensing fiber, an optical annular device, a second erbium doped fiber amplifier, a polarization scrambler, an electro-optical intensity modulator, a second polarization controller, an arbitrary waveform generator, an optical filter, a photoelectric detector and a signal collecting and processing system. On the premise that the high spatial resolution of a BOTDA system is maintained, the BOTDA instrument ensures the sensing distance and the measuring precision of the system, and improves the sensing performance of the system.

The invention discloses a distributed fiber sound wave detection apparatus and method based on wave beam formation. The apparatus comprises a light source, a 1*2 coupler, a control and signal processing unit, an arbitrary waveform generator, a double-channel parallel Mach-Zehnder electro-optical modulator, a reference arm fiber, an erbium doped fiber amplifier, an optical filter, an annular device, a front-end reflector, a reference length fiber, a rear-end reflector, a sense fiber, a 90-degree optical mixer, and a balance detector. The method includes the steps: injecting signal light into the sense fiber, the signal light being modulated to be light pulses with a fixed frequency on a lower side and a sweep frequency on an upper side; mixing the returned signal light carrying light phase information and light frequency spectrum information of detecting points with local reference light; demodulating the light phase information and the light frequency spectrum information, and obtaining the frequency, amplitude and phase information of sound waves in the detecting points in the sense fiber; and finally calculating the position, intensity and frequency information of sound sources. The sensing function and the transmission function of a fiber are combined into one function. Therefore, the distributed fiber sound wave detection apparatus and method have the advantages that the detecting point scale is hundred times higher than that of the prior art.

The invention discloses a high-speed demodulation method for a high-capacity weak grating sensing network. The method comprises the following steps: (1) inscribing a plurality of weak gratings FBGr, FBG1, FBG2, FBG3 and the like in sequence on an optical fiber, wherein the FBGr is taken as a reference grating, and the FBG1, FBG2, FBG3 and the like are divided into m (m is more than or equal to 1) groups of identical weak grating arrays for constructing a sensing network; (2) generating pulse light by using a pulse laser, introducing the pulse light into the reference grating and the sensing network through an optical circulator, returning the reflected signal of each weak grating to the optical circulator, and introducing the reflected signals into an erbium-doped optical fiber amplifier for amplifying; (3) feeding the amplified reflected signals into a dispersion compensation optical fiber, receiving the time of the reflected signal of each weak grating by using a photoelectric detector, and performing signal processing through a high-speed data acquisition system to obtain the wavelength change of each weak grating in the sensing network in order to realize demodulation. A high-speed demodulation device for the high-capacity weak grating sensing network mainly comprises a pulse laser, an optical circulator, an optical fiber inscribed with a plurality of weak grating, am erbium-doped optical fiber amplifier, a dispersion compensation optical fiber, a photoelectric detector and a high-speed data acquisition system.

The invention relates to a system for realizing network extension and protection functions with wave-division multiplexing annular optical access networks and a method for realizing the network extension and protection functions with the wave-division multiplexing annular optical access networks. The system is characterized in that an OLT (optical link terminal) is connected with M RNs (remote nodes) through an optical fiber to form an annular network, and the remote nodes are connected with ONUs (optical network units) through a distributed optical fiber, wherein the optical link terminal mainly comprises Q=Mq (1+n) optical transmitters, Q receivers, Mq transmitting C wave-band wavelength, Mnq transmitting L wave-band wavelength, Q 1X2 optical switches, three AWGs (arrayed waveguide gratings) of an identical structure and with Q ports, two EDFAs (erbium-doped fiber amplifiers), two optical circulators and a 2X1 coupler; and each remote node on a main ring mainly comprises a 2X2 optical switch, a 1X2 optical switch, two WBs (wavelength blockers), a CWDM (coarse wavelength division multiplexing), four common circulators, a closed circulator, six couplers and an arrayed waveguide grating. A feeder optical fiber is protected by the aid of use of the optical switches at the OLT end and designs of the annular structures and RN structures. By means of effective arrangement of the RN nodes, network scale extension can be realized, typical annular tangent topological structures are realized, network coverage area is greatly widened, and the quantity of users is greatly increased. The system realizes dynamic dispatching of the wavelength by adjusting the wavelength blockers and changing operating ports of the arrayed waveguide gratings, and achieves balance between the cost and the performance.

A system includes an optical transmitter that outputs an optical signal having a substantially Gaussian waveform and an optical receiver that is optically coupled to the optical transmitter and has an impulse response essentially matching the waveform. The impulse response and waveform preferably match in the time domain. The transmitter and receiver may be average-power-limited, using, for example, an erbium-doped fiber amplifier. To achieve a high signal-to-noise ratio, the waveform may be designed to minimize jitter, sample duration, matching parasitics, and inter-symbol interference (ISI). Such a waveform may be a return-to-zero (RZ) Gaussian or Gaussian-like waveform and may be transmitted in a variety of modulation formats. Further, the system may be used in WDM or TDM systems. A method for characterizing the time domain impulse response of an optical element used in the optical receiver is provided, where the method is optionally optimized using deconvolution and / or cross-correlation techniques.

The invention discloses a microwave photon up-conversion device and method based on a photoelectric oscillator and belongs to the technical field of microwave photonics. The device is composed of a laser source, a first coupler, a first circulator, a first high nonlinearity dispersion displacement optical fiber, an erbium-doped optical fiber amplifier, a first photoelectric detector, a second coupler, a first Mach-Zehnder modulator, a first microwave signal source, a first direct current voltage-stabilized power supply, an optical filter, a second Mach-Zehnder modulator, a second direct current voltage-stabilized power supply, a second circular, a second high nonlinearity dispersion displacement optical fiber, a second photoelectric detector, a microwave amplifier, a double-parallel Mach-Zehnder modulator, a third direct current voltage-stabilized power supply, a fourth direct current voltage-stabilized power supply, a fifth direct current voltage-stabilized power supply, an optical isolator and a spectrum analyzer. A Brillouin frequency shift value f of the high nonlinearity optical fiber is 9.2GHz, and a signal with frequency of f<m> can be up converted to f<m>+18.4GHz, so alow quality and low frequency intermediate signal is converted into a high quality and high frequency signal.

The invention discloses a producing method which is easily implemented and can output stable single-longitudinal-mode multi-wavelength broadband-tunable brillouin laser, and a brillouin laser device. The method uses the brillouin laser device which is composed of an optical passive resonant cavity and an erbium-doped fiber amplifier arranged at the outer part of the optical passive resonant cavity, brillouin stokes light generated in the optical resonant cavity is fed back to the erbium-doped fiber amplifier, and therefore the single-longitudinal-mode multi-wavelength broadband-tunable brillouin laser is obtained. The brillouin laser device comprises the erbium-doped fiber amplifier, a tunable laser device and the optical passive resonant cavity, wherein the erbium-doped fiber amplifier is arranged at the outer part of the optical passive resonant cavity; the tunable laser device is connected with the erbium-doped fiber amplifier through a fiber coupler; and the optical passive resonant cavity is connected with the output end of the erbium-doped fiber amplifier. Meanwhile, the optical passive resonant cavity is connected with the input end of the erbium-doped fiber amplifier through the fiber coupler.

The invention discloses a phase modulation signal full-optical wavelength conversion device. The phase modulation signal full-optical wavelength conversion device comprises a tunable dispersion compensator, an erbium-doped optical fiber amplifier, a variable optical attenuator, a tunable laser, a polarization controller, an optical beam splitter, a first optical coupler, a high-nonlinearity optical fiber, an optical filter and a signal demodulating and monitoring device. An output port of the tunable laser with the narrow linewidth is connected with an input port of the polarization controller. An output port of the polarization controller is connected with an optical integration port of the optical beam splitter. One optical splitting port of the optical beam splitter and an output port of the variable optical attenuator are connected with two optical splitting ports of the first optical coupler respectively. The first optical coupler, the high-nonlinearity optical fiber and the optical filter are sequentially connected. An output port of the optical filter and the other optical splitting port of the optical beam splitter are connected with a signal input port of the signal demodulating and monitoring device and a local oscillator input port of the signal demodulating and monitoring device respectively. Through the utilization of the phase modulation signal full-optical wavelength conversion device, harmonic suppression can be achieved, and signal quality is improved.

Provided is an erbium-doped fiber amplifier reducing transient phenomena of a signal-to-noise ratio and a bit error rate in a dynamic wavelength division multiplexing system and an amplifying method using the erbium-doped fiber amplifier. The erbium-doped fiber amplifier includes: a polarization scrambler modulating a polarization state of an input signal to remove a polarization of the input signal; an amplifier amplifying the input signal from which the polarization has been removed; a detector reading powers of input and output signals of the amplifier; and an automatic gain controller controlling currents of the pump LDs according to the powers of the input and output signals read by the detector 1630 to maintain the gain even if the power of input signal changes.

The invention relates to a radio over fibre system, comprising a central station, a base station and a downlink link fibre. The central station comprises a laser, a DQPSK (Differential Quadrature Reference Phase Shift Keying) lithium niobate modulator and an erbium-doped fibre amplifier, which are connected in turn in series through an optical fibre. The DQPSK lithium niobate modulator is in a push-pull mode and used for generating quadruple harmonic wave including a cosine microwave signal and OFDM-QPSK (Orthogonal Frequency Division Multiplexing-Quadrature Reference Phase Shift Keying) data information side frequency component carried by the quadruple harmonic wave. By adjusting bias voltage, the base station can obtain a local oscillation signal for uplink receiving demodulation and a millimetre wave signal in required power and carrying the OFDM-QPSK data information and send the obtained millimetre wave signal through an antenna. In the invention, the DQPSK lithium niobate modulator composed of three Mach-Zehnder modulators is adopted to generate steady millimetre waves; an optical filter is saved; the structure is simplified; the cost is reduced; and the system is easy to realize commercial applications.

The invention aims to provide an erbium-doped fiber amplifier control system. In the hardware structure, the control system can be applied to erbium-doped fiber amplifiers of various functions. The control system comprises a control module, three power control loops, two pump laser driver modules, and one adjustable light attenuation driver module, wherein both an input light power detection end and an output light power detection end of each power control loop are connected with a signal input end of the control module, a drive signal input end of each pump laser driver module is connected with a signal output end of the control module, a drive signal output end of each pump laser driver module is used for connecting with a pump laser of a to-be-controlled erbium-doped fiber amplifier, adriver signal input end of the adjustable light attenuation driver module is connected with the signal output end of the control module, and a driver signal output end of the adjustable light attenuation driver module is used for connecting with a to-be-controlled adjustable light attenuator.

The invention discloses a frequency-stable photoelectric oscillator based on a passive compensation mode and a method thereof. The frequency-stable photoelectric oscillator based on a passive compensation mode comprises an oscillation loop consisting of a first semiconductor laser, a first Mach-Zehnder modulator, an optical coupler, a long optical fiber, a wavelength division multiplexer, an erbium-doped optical fiber amplifier, a first photoelectric detector, a first microwave band-pass filter, a first microwave amplifier, a microwave frequency multiplier, a second microwave band-pass filter,a second microwave amplifier, a microwave phase shifter and a microwave coupler, and a compensation loop consisting of a second semiconductor laser, a second Mach-Zehnder modulator, an optical coupler, a long optical fiber, a wavelength division multiplexer, a second photoelectric detector, a third microwave band-pass filter, a third microwave amplifier and a microwave coupler. The low-phase-noise and stable high-frequency microwave / millimeter wave signals can be generated, the traditional complex frequency stabilization mode based on electric control feedback does not need to be adopted, andthe method has the advantages of being low in cost, easy to implement and the like.

The embodiment of the invention discloses a hybrid optical fiber amplifier, an optical signal amplification method and an optical communication system. The hybrid optical fiber amplifier comprises: anerbium-doped optical fiber amplifier which is used for amplifying optical signals of C and L wave bands in an optical path and filtering out parts, with gain exceeding a set threshold value, in the amplified optical signals of the C and L wave bands, so that the power of the optical signals of the C and L wave bands output to the rear end of the optical path is balanced in each channel; and a lumped Raman optical fiber amplifier, wherein the input end of the lumped Raman optical fiber amplifier is connected with the output end of the erbium-doped optical fiber amplifier through a high-nonlinearity optical fiber or a dispersion compensation optical fiber, and the lumped Raman optical fiber amplifier is used for amplifying the optical signals which are not amplified by the erbium-doped optical fiber amplifier in the output optical signals of the C waveband and the L waveband. The EDFA and Raman belong to lumped optical fiber amplifiers, the gain control can be realized through local input and output power detection, and the gain control is very convenient.

The invention relates to a multi-wavelength stable output method and its device of linear structure optical fiber laser based on the mixing gain of fiber Raman amplifiers and erbium-doped optical fiber amplifier. It includes optical fiber annular lens, optical coupler, fiber Raman amplifiers, erbium-doped optical fiber amplifier, and Sagnac ring filter. The Sagnac ring filter includes two polarisation controllers whose one end are respectively connected with synthetic end of the 3dB optical coupler. The invention combines the fiber Raman amplifiers and the erbium-doped optical fiber amplifier to restrain wavelength competition characteristic of the latter to realize optical fiber laser multi-wavelength stable output.

The invention discloses an optimal design method of a few-mode erbium-doped optical fiber amplifier. The optimal design method comprises the following steps of: firstly, measuring a loss coefficient and a particle number inversion coefficient of each mode in a sample fiber; secondly, determining an inversion particle number and an erbium-doped fiber length required for achieving a designed gain target; and finally, calculating and verifying whether the gain performance of each mode of signal light meets a design requirement or not. Therefore, according to the designed target gain, the erbium-doped fiber amplifier is optimally designed in a mode of reversing the particle number as required, and the erbium-doped fiber amplifier has the advantages of high design efficiency, easiness in implementation and high adaptability.

A method and devices for individually controlling the signal strength of single or multiple optical channels. A controller module monitors the signal strength of channels and amplifies those that need amplifying while attenuating those that are too strong using the same Erbium doped fiber amplifier. A controllable compensation module receives at least one channel and, when required, can either amplify or attenuate the signal strength of the channels. The module can be constructed out of a single fiber with an associated pump laser. If the laser provides insufficient pumping power, the fiber acts as an attenuator. If the laser provides a higher level of pump power, the fiber acts as an amplifier.

The invention discloses a few-mode erbium-doped optical fiber. A fiber core of the few-mode erbium-doped optical fiber comprises a first layer, a second layer and a third layer from inside to outside,the first layer is round, the second layer is in a first annular shape, the third layer is in a second annular shape, and the refractive index of the second layer is larger than the refractive indexof the first layer and larger than the refractive index of the third layer. The erbium ion doping concentration of the second layer is less than the erbium ion doping concentration of the first layerand less than the erbium ion doping concentration of the third layer. According to the scheme provided by the invention, gain flatness among transmission modes can be realized only through single-fundamental-mode pumping, and weak coupling transmission of a to-be-amplified signal in the few-mode erbium-doped fiber is realized at the same time.

The invention relates to the optical fiber F-P sensor vibration signal demodulation system based on polarization switching and a demodulation method, belonging to the optical fiber sensing and the signal demodulation field. The device consists of a wide spectrum light source, a polarization-preserving fiber grating, a polarization-preserving circulator, a polarization-preserving er-doped optical fiber amplifier, an electro-optical modulator, a signal generator, an analyzer, a circulator, an electro-optical modulator, a high speed data collection card, a computer, a power amplifier, a vibration table and an optical fiber F-P sensor. The invention overcomes the problem that the optical path is imbalance in the traditional dual-wavelength demodulation system and realizes two-path interference signal demodulation on same light source, the photoelectric detector and on the same light path. In the mean time, the invention provides a two-path signal demodulation method combining an ellipse fitting alogrithm and a differential cross multiplication algorithm. The two-path signal demodulation method can effectively avoid the inaccuracy of the demodulation system which is caused by the F-P sensor cavity long manufacture technology.

An optical amplifier is described that comprises at least two sections of amplifying optical fibre and pumping means for optically pumping the amplifying optical fibre. Optical fibre support means, for example a channel or channels in a substrate, are also provided to hold the two or more sections of amplifying optical fibre substantially straight during use. The optical fibre support means also includes a means for coupling light between the at least two sections of amplifying optical fibre. The at least one amplifying optical fibre may comprise an Erbium doped core to provide an erbium doped fibre amplifier (EDFA).

The invention discloses a quantum-classic common fiber transmission system based on mode division multiplexing. The quantum-classic common fiber transmission system comprises two classic signal transmitters, a QKD transmitter, a first mode multiplexer, a second mode multiplexer, an EDFA, a mode demultiplexer, an MIMO digital signal processing unit, two classic signal receivers, a QKD receiver anda transmission link. The transmission link adopts few-mode optical fiber transmission and comprises N erbium-doped optical fiber amplifiers. The receiving end comprises a mode demultiplexer, a digitalsignal processing MIMO, two classic signal receivers and a QKD receiver. On the basis of increasing the transmission capacity through mode division multiplexing, the power of the pump light in the erbium-doped optical fiber amplifier can be automatically adjusted according to the bit error rate of a classic signal receiving end and the bit error rate of a quantum signal receiving end, and MDL damage in an MDM system is reduced.

A multi-band double-chirp microwave signal generation and anti-optical fiber dispersion transmission system comprises a light source, a microwave source, a 90-degree electric coupler, a waveform generator, a three-channel direct-current voltage source, a Mach-Zehnder modulator, an erbium-doped optical fiber amplifier, a single-mode optical fiber, a polarization controller, a polarizer and a photoelectric detector. According to the invention, + 1, -3-order single sideband modulation of single-frequency carrier modulation and + / -2-order double sideband modulation of low-frequency single chirp signal modulation in two vertical polarization states are realized by using the double-parallel double-polarization Mach-Zehnder modulator, the polarization state of the signal is adjusted by the polarization controller after optical fiber transmission, and the polarization state is synthesized by the polaroid. And finally, detection is carried out by a photoelectric detector to realize double-frequency-band quadruple-bandwidth double-chirp microwave signal generation and anti-optical-fiber dispersion transmission.

The invention relates to a slow light caching shaper for an adjustable loop consisting of N paths of optical signals, which is suitable for storing, controlling and processing high-speed optical signals. A first interface of a first optical circulator (61) is connected with an optical signal (1) via a first erbium doped fiber amplifier (41); N bifurcated ports of an N*1 optical coupler (5) are successively connected with first to Nth pumping light sources (21, 22...2N) through first to Nth adjustable optical attenuators (31, 32...3N), and an in-line port of the N*1 optical coupler (5) is connected with a first interface of a second optical circulator (62) via a second erbium doped fiber amplifier (42); second interfaces of the first and second optical circulators (61, 62) are respectively connected with first and second ports of the a 2*2 optical switch (7), and third interfaces of the first and second optical circulators (61, 62) are respectively connected with an optical isolator (9) and an optical filter (10); and third and fourth ports of the 2*2 optical switch (7) are connected via a single-mode fiber (8).

The invention relates to the technical field of optical fiber communication, in particular to an erbium-doped optical fiber amplifier temperature monitoring and early warning method, which comprises the following steps: acquiring the temperature of a pump laser in each erbium-doped optical fiber amplifier during normal operation within a period of time, and optionally selecting two groups of data as a first temperature sequence and a second temperature sequence; calculating a difference value and a similarity between the first temperature sequence and the second temperature sequence, and a mean value of ratios of corresponding elements in the two sequences, obtaining an ambient temperature difference of the two erbium-doped optical fiber amplifiers according to the difference value, the similarity and the mean value, and further obtaining an ambient temperature difference set; classifying the temperature difference set to obtain a classification result, wherein the classification result comprises a plurality of categories; isolated samples in the classification result are obtained and recorded as temperature abnormal samples, and early warning is carried out on the erbium-doped optical fiber amplifier corresponding to the temperature abnormal samples. The temperature of the erbium-doped optical fiber amplifier can be monitored in real time more visually, and the phenomenon of abnormal temperature is prevented.

The invention provides a transmission system based on a hybrid optical fiber amplifier, and the system comprises: an erbium-doped optical fiber amplifier which is used for amplifying optical signals of a C wave band and an L wave band in an optical signal; a first-order Raman optical fiber amplifier, wherein the output end of the erbium-doped optical fiber amplifier is connected with the input end of the first-order Raman optical fiber amplifier, and the first-order Raman optical fiber amplifier is used for amplifying a wave band which is not amplified by the erbium-doped optical fiber amplifier in the optical signal; a second-order Raman optical fiber amplifier, wherein the input end of the second-order Raman optical fiber amplifier is connected with the output end of the first-order Raman optical fiber amplifier, and the C + L wave band optical signal is further amplified. The erbium-doped optical fiber amplifier is used for amplifying a C wave band and an L wave band in the optical signal, but wavelength loss easily occurs, so that the first-order Raman optical fiber amplifier is added behind the erbium-doped optical fiber amplifier, full wave bands can be amplified, the wavelength loss caused by the erbium-doped optical fiber amplifier can be made up, the second-order Raman optical fiber amplifier is connected, The transmission system is suitable for long-distance relay-free transmission.

The invention belongs to the field of distributed optical fiber sensing, and discloses a distributed optical fiber Raman sensing device and method based on chaotic laser. The device comprises a semiconductor laser, the emitted laser is divided into two beams through a circulator and a first coupler, one beam passes through a first erbium-doped optical fiber amplifier, a nonlinear optical fiber, apolarization controller and a circulator and then returns to the semiconductor laser to enable the semiconductor laser to output broadband chaotic laser, the other beam is subjected to pulse modulation through an acousto-optic modulator to generate chaotic pulse laser, the chaotic pulse laser is divided into two paths through a second coupler, one path is detected by a third detector, and the other path enters a sensing optical fiber through a wavelength division multiplexer, raman scattering and Rayleigh scattering happen to all points in the sensing optical fiber, then the signals are returned to the wavelength division multiplexer, output and then detected by the first photoelectric detector and the second photoelectric detector respectively, temperature and strain information along thesensing optical fiber is demodulated from detection signals, and submillimeter-level resolution distributed optical fiber Raman sensing can be achieved.

The invention discloses a communication rate adaptive control method and a system of a satellite laser communication subsystem. The system comprises a ground pulse light emitting module, a backward light detecting module, a data processing and feedback module. The ground pulsed light emitting module comprises a pulsed laser emitter and an erbium doped fiber amplifier which are non-signal light andonly serve as a test light path to detect atmospheric loss. The backward light detection module comprises a detector and a data acquisition card. When the emitted laser pulse is transmitted in a freechannel, the detector detects backward scattered light of the emitted pulse light, and the power of the backward scattered light detected by the detector is collected in real time by the data acquisition card. The data processing and feedback module is a computer. The invention can simply and quickly realize the self-adaptive adjustment of the communication rate of the satellite laser communication subsystem and improve the data rate of the current satellite laser communication system.

The invention discloses a distributed optical fiber sensing system for low-frequency detection. The distributed optical fiber sensing system comprises a pulsed light generation module, an erbium-dopedoptical fiber amplifier, a first coupler, a first Michelson interferometer, a first photoelectric detector and a data acquisition processing feedback card which are annularly connected; a circulator;a phase signal acquisition module, wherein the phase demodulation circuit comprises a second Michelson interferometer, one port of the second Michelson interferometer is connected to a second photoelectric detector, the other electrical port of the second Michelson interferometer is connected to a carrier circuit, and the second photoelectric detector and the carrier circuit are connected to a data acquisition card; and a signal processor which receives a phase signal to be demodulated and demodulates the phase signal through a phase generation carrier demodulation algorithm. According to thedistributed optical fiber sensing system disclosed by the invention, by introducing a closed-loop feedback function, low-frequency noise introduced by slow change of devices such as a high-coherencelight source, an acoustic optical modulator and the erbium-doped optical fiber amplifier and the environment is suppressed, and the problems of high low-frequency noise and difficulty in effectively detecting low-frequency vibration signals in an existing distributed optical fiber acoustic sensing technology are solved.