117 results about "Fiber amplifier" patented technology

The invention provides a satellite-borne EDFA on-orbit performance degradation monitoring method and system. The satellite-borne EDFA on-orbit performance degradation monitoring method comprises the steps that a health baseline is preset; closing input light and a first-stage pump of the satellite-borne EDFA; driving a second-stage pump of the satellite-borne EDFA to maintain fixed power output, and recording the working temperature of the second-stage pump; acquiring the monitoring optical power of the second-stage pump and the spontaneous radiation power of the output end of the satellite-borne EDFA; calculating to obtain spontaneous radiation conversion rate; and carrying out satellite-borne EDFA degradation determination. The method has the beneficial effects that the interference of temperature fluctuation on a monitoring result is greatly reduced through the spontaneous radiation conversion rate which is a relative parameter, and the method is adaptive to a complex thermal environment of a satellite; degradation is judged based on a preset health baseline, precise monitoring of the performance state of the satellite-borne EDFA is achieved, and a reliable basis is provided for maintenance. Precise positioning of a degraded part is realized, a fault source is clear, blind maintenance is avoided, and the maintenance efficiency is improved; monitoring can be completed in a second level and can be arranged to be carried out in a communication intermittent period, and normal communication service of the satellite is not affected.

The invention provides an optical feedback resonance enhanced forward Brillouin demodulation structure, which comprises a tunable laser, a first polarization controller, an erbium-doped optical fiber amplifier, an optical coupler, an optical isolator, a forward Brillouin gain optical fiber, a band-pass filter and a photoelectric detector, a second polarization controller; and a spectrum analyzer. The first polarization controller is connected with a port a of the optical coupler, a port b of the optical coupler is connected with an input end of the erbium-doped optical fiber amplifier, an output end of the erbium-doped optical fiber amplifier is connected with the optical isolator, the optical isolator is connected with the band-pass filter, the band-pass filter is connected with the forward Brillouin gain optical fiber, and the optical fiber is fed back to a port c of the coupler through the second polarization controller. The output power of the erbium-doped optical fiber amplifier is controlled, and the polarization states of the pump light and the feedback laser are controlled by the first polarization controller and the second polarization controller, so that the forward Brillouin effect is amplified.

Disclosed is a pulsed laser apparatus and method of generating a laser pulse. The apparatus includes an input coupler configured to receive pumping light from a pumping light source and a seed pulse from a seed pulse generator. The apparatus further includes a doped fiber-optic cable with an input port at a first end configured to receive the pumping light and the seed pulse. The doped fiber-optic cable amplifies the seed pulse to generate an output pulse. Along a first length of the doped fiber optic cable, the pulse spectrum broadens rapidly owing to nonlinearity. Beyond the first length in an extended portion, the output pulse shifts towards longer wavelengths and broadens in both spectral and temporal domains. The apparatus also includes an output port at a second end of the doped fiber-optic cable, wherein the output pulse exits the doped fiber-optic cable at the output port.

By utilizing soliton self-frequency shift modulation, the formation of multiple pulsed light beams is suppressed, while the occurrence of ASE (Autonomous Emission Reduction) is suppressed, and the modulated pulsed light beam is reliably amplified. [Solution] The pulsed light generation device 100 comprises an oscillator 1 that oscillates pulsed light L, a fiber amplifier 2 located downstream of the oscillator 1 in the optical path of the pulsed light L, a soliton shift fiber 5 located downstream of the fiber amplifier 2 in the optical path of the pulsed light L, a branching section 8 located downstream of the fiber amplifier 2 in the optical path of the pulsed light L, and a short-wavelength fiber amplifier 11 located downstream of the soliton shift fiber 5 and the branching section 8 in the optical path of the pulsed light L.

A fiber amplifier to amplify seed light has a laser diode, an optical fiber segment, and a doped fiber. The laser diode generates pump light at a pump wavelength from an end facet, and optical fiber segment in optical communication with the pump light has a fiber Bragg grating (FBG) configured to lock the pump light from the end facets to the pump wavelength. The pump light from the laser diode interact with an active dopant of the doped fiber and can thereby amplifies the seed light. To provide less coherent light and improve stability of the laser diode over operation conditions, variations in refractive index in the FBG have a chirped period changing linearly along a length of the FBG. The chirped period shifts the reflectivity asymmetrically from a central wavelength region of the FBG, such as blue-shifting the reflectivity for a short wavelength.

This invention belongs to the field of fiber lasers, specifically relating to an SBS suppression module, a fiber main amplifier, and a high-power narrow-linewidth laser. The SBS suppression module includes a polarization beam combiner and a 1×2 optical switch; the fiber main amplifier consists of a double-clad gain fiber, the SBS suppression module, and accompanying passive fiber devices; the high-power narrow-linewidth laser is composed of a narrow-linewidth laser seed source, a fiber preamplifier, and a fiber main amplifier connected sequentially, with the fiber preamplifier consisting of three stages of single-clad fiber amplifiers. The SBS suppression module effectively suppresses SBS, and its simple structure facilitates packaging. This invention enables narrow-linewidth fiber laser output with high beam quality at the 5kW level and above, and employs all-fiber fusion splicing technology to construct an all-fiber system, offering advantages such as compact and simple structure, good stability, increased power, and low cost.

This invention proposes a random microwave pulse generation system and method based on an optoelectronic oscillator, belonging to the field of microwave photonic signal generation and processing technology. The system includes a laser, a polarization controller, a closed-loop optoelectronic oscillator (OEO) loop, a random fiber grating string, and a function generator; wherein the closed-loop optoelectronic oscillator (OEO) loop mainly consists of a Mach-Zehnder modulator, a circulator, an erbium-doped fiber amplifier, a photodetector, an electrical amplifier, and a directional coupler.

A temperature strain separable dynamic and static combined measurement distributed optical fiber sensing system, comprising: laser, optical modulator, radio frequency signal generator, optical filter, DFB laser, polarization controller, first acoustooptic modulator, depolarizer, erbium-doped fiber amplifier, two optical circulators, optical wavelength division multiplexer, receiving module, signal acquisition and processing module are arranged in sequence, the application carries out temperature sensing to the back Raman scattering light of the pulse while receiving the Rayleigh scattering light of the detection pulse, and controls the time interval of adjacent pump pulse and detection pulse to carry out three-bit pulse coding and decoding, so that the back Raman scattering signals of individual pulse in pulse pair are separated in time, and finally the simultaneous measurement of dynamic variable (vibration) and static variable (temperature, static strain) is realized and the spatial resolution of measurement is ensured not to be lost.

The invention relates to the technical field of optical fiber amplifiers, and discloses a main and backup optical fiber amplifier structure and a preparation method.The amplifier structure comprises a shell, a beam splitter, a main optical fiber amplification light path and a backup optical fiber amplification light path, the shell comprises a bottom plate and a side wall, the main optical fiber amplification light path at least comprises a main optical fiber, and the backup optical fiber amplification light path at least comprises a backup optical fiber; the backup optical fiber amplification optical path at least comprises a backup optical fiber, the beam splitter is connected with the main optical fiber amplification optical path and the backup optical fiber amplification optical path, an annular groove is formed in the lower surface of the bottom plate, an annular partition plate is formed in the corresponding position of the annular groove in the upper surface of the bottom plate, and the main optical fiber is wound in the annular groove; the backup optical fiber is wound around the outer side of the annular partition plate, and the main optical fiber and the backup optical fiber are physically separated through the annular partition plate. According to the technical scheme provided by the invention, the redundancy and robustness of the main and backup optical fiber amplifiers can be improved.

The invention belongs to the technical field of lasers. The invention provides an all-fiber laser with adjustable pulse width and a pulse width tuning method. The all-fiber laser comprises a narrow-band dissipation soliton mode-locked fiber laser seed source, a first fiber isolator, a fiber amplifier, a second fiber isolator, an optical circulator and a dispersion element which are sequentially arranged along a light path. The seed source generates a mode-locked pulse with a fixed initial spectral width; the nonlinear effect intensity is controlled by adjusting the driving current of the pumping source, so that the spectrum broadening amount of the pulse in the amplification process is regulated and controlled, the variable total spectrum width is formed, the spectrum width is subjected to linear time-frequency mapping through a dispersion element with a fixed group delay dispersion value, and finally continuous and electric control adjustment of the output pulse width is achieved. The whole system adopts an all-fiber structure, has the advantages of high stability, compact structure, good tuning linearity and the like, and is suitable for industrial processing, sensing and scientific research application scenes needing flexible pulse width regulation and control.

The application discloses an optical frequency comb automatic recovery device and method, and belongs to the field of silicon-based nonlinear optical photoelectric modulation. The application comprises a laser, an IQ modulator, an acousto-optic modulator, a fiber amplifier, a polarization controller, a micro-ring resonator, a phase-locked loop, an arbitrary waveform generator, a photoelectric detector, a PID module and an upper computer. Transmission loss of an optical frequency comb debugging system is tested, which comprises fiber loss before laser enters a microcavity and transmission loss after the laser enters the microcavity; the output frequency range of the phase-locked loop is adjusted, and frequency scanning is performed on the microcavity; laser wavelength is entered from blue detuning, the output power of the laser is gradually reduced through the acousto-optic modulator, and the wavelength is kept unchanged; when the PID detects a power rise, the laser power is quickly raised until the PID detects a rising step; the laser frequency is slowly increased and the power is kept unchanged until a single soliton optical frequency comb is observed; when the single soliton disappears, the control steps after the laser wavelength is entered from blue detuning are repeated, and the optical frequency comb is automatically recovered.

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.

The invention belongs to the technical field of temperature control equipment, and particularly relates to a one-source two-channel intelligent modulation frequency doubling light system based on an ILTA-EDFA-IQ-PPLN integrated architecture, which comprises a light path execution subsystem, a light path control subsystem, a light path control subsystem and a light path control subsystem, the device comprises a narrow linewidth laser, at least one erbium-doped optical fiber amplifier, at least one IQ orthogonal optical signal modulator, at least one periodically poled lithium niobate nonlinear frequency doubling device and a plurality of optical splitters, and is used for generating and regulating the conversion from 1560nm-waveband laser to 780nm-waveband laser; according to the invention, through a'one-source dual-channel 'topological design, high-stability narrow-linewidth laser and high-power adjustable laser are provided at the same time, and the function flexibility of the system is improved. According to the design, the system can adapt to multi-scene requirements in atom detection, such as cold atom interference, atom cooling capture and atom excitation detection, and multiple sets of laser systems do not need to be additionally configured, so that the use cost and complexity are reduced.

The invention discloses a multimode cladding pumping resonance space division multiplexing optical fiber amplifier and an implementation method thereof, and relates to the technical field of optical fiber amplifiers. The multimode cladding pumping resonance space division multiplexing optical fiber amplifier comprises a transmission optical fiber, an active optical fiber, a multimode pumping optical fiber and a resonant cavity; the active optical fiber is one of a multimode optical fiber, a multi-core optical fiber and a multi-core multimode optical fiber and is used for realizing stimulated radiation amplification of multichannel signal light; the multi-mode pumping optical fiber is coupled with the active optical fiber through a pumping coupling assembly to form a pumping injection path which is used for accessing an external multi-mode pumping source and injecting pumping light into a cladding of the active optical fiber; by constructing a resonant light path for pumping recycling, residual pumping is converted into reusable effective pumping, so that the residual pumping participates in the pumping effect on the active section for multiple times in the system, the equivalent pumping intensity and the accumulative absorption amount of the active section are improved under the condition that the rated power of an external pumping source is not remarkably increased, and the energy consumption of the active section is reduced. The purposes of improving the gain efficiency and reducing the thermal load are achieved.

The invention provides an oil and gas pipeline hydrate generation monitoring system and method based on a phi-OTDR, and belongs to the technical field of pipeline natural gas monitoring. Comprising an external cavity laser, a coupler, an acousto-optic modulator, a first erbium-doped amplifier, a circulator, a to-be-detected optical fiber, a to-be-detected pipeline, a second erbium-doped amplifier, an attenuator, a frequency mixer, an optical detector, a low-pass filter, a data acquisition card and an upper computer. The external cavity laser is connected with the coupler, the coupler is connected with the acousto-optic modulator, the acousto-optic modulator is connected with the first bait-doped amplifier, the first bait-doped amplifier is connected with the circulator, the optical fiber to be measured is tightly laid on the outer wall of a pipeline to be measured, a port of the circulator is connected with the end of the optical fiber to be measured, and the circulator is connected with the second bait-doped amplifier. The second erbium-doped amplifier is connected with the attenuator, the attenuator is connected with the frequency mixer, the frequency mixer is connected with the coupler and the optical detector, the optical detector is connected with the low-pass filter, the low-pass filter is connected with the data acquisition card, and the data acquisition card is connected with the upper computer.

The invention provides a compact integrated broadband test system, which comprises a TFLN integrated chip module, an optical fiber pumping and modulation module, a terahertz radiation and receiving module and a data acquisition and analysis module, and is characterized in that all the modules are integrated to adapt to 200GHz-3.5 THz terahertz radio communication and radar test requirements; the TFLN integrated chip module comprises a TFLN integrated chip, and a thin film lithium niobate TFLN with the x cutting thickness of 500-700 nm is bonded to a SiO2 / 500 [mu] m high-resistance silicon substrate with the thickness of 4700 nm; the optical fiber pumping and modulation module comprises a mode-locked laser, a dispersion compensation unit, a Mach-Zehnder modulator (MZM) and an erbium-doped optical fiber amplifier (EDFA); the terahertz radiation and receiving module comprises a transmitting link, a receiving link and an optical detection branch; the data acquisition and analysis module comprises a balanced photoelectric detector PD, a data acquisition card and analysis software, the terahertz radio communication and radar test requirements can be subjected to data linkage analysis, the test process is simple, and time is saved.

The utility model relates to an ultra-compact erbium-doped optical fiber amplifier which comprises a pump laser, a composite isolation-wavelength division multiplexer integrated with erbium-doped optical fibers and an isolator integrated with erbium-doped optical fibers. The common end of the composite isolation-wavelength division multiplexer and the input end of the isolator share the same erbium-doped optical fiber; the pumping end of the composite isolation-wavelength division multiplexer is connected with the pumping laser and is used for introducing pumping light generated by the pumping laser into the erbium-doped optical fiber; the signal end is used for introducing signal light into the erbium-doped optical fiber; the common end is used for outputting, and an optical fiber of the common end is an erbium-doped optical fiber; the optical fiber at the input end of the isolator is an erbium-doped optical fiber, and the output end of the isolator is used for outputting the amplified signal light. One end of each optical device integrated with the erbium-doped optical fiber shares the same erbium-doped optical fiber, and two ends of the erbium-doped optical fiber have no melting points, so that the problem that in the prior art, the erbium-doped optical fiber needs to be welded with tail fibers of the optical devices in an erbium-doped optical fiber amplifier module, and a large space needs to be reserved for protecting the melting points is solved; therefore, the erbium-doped optical fiber amplifier module is further miniaturized.

The utility model relates to optical communication network equipment technical field more specifically, relate to a kind of single-pumped bipolar erbium-doped fiber amplifier.A kind of single-pumped bipolar erbium-doped fiber amplifier, comprising: signal light source, optical isolator, coupler, pump laser, first-stage erbium-doped fiber and second-stage erbium-doped fiber;The output end of signal light source is connected with the first input end of coupler, and the output end of pump laser is connected with the second input end of coupler;The coupler, first-stage erbium-doped fiber, optical isolator and second-stage erbium-doped fiber are sequentially connected.

The technology of this application relates to an optical component constituting a fiber amplifier, a fiber amplifier, and a manufacturing method. The optical component is connected to a gain fiber by using a first fiber, or the optical component is directly connected to the gain fiber. The optical component is connected to one or more second optical components in the fiber amplifier by using a second fiber, and / or the optical component inputs an optical signal or outputs an optical signal amplified by the gain fiber by using the second fiber. Softening temperatures and / or refractive indexes of the first fiber and the second fiber are different, or softening temperatures and / or refractive indexes of the second fiber and the gain fiber are different.

The application discloses a kind of asymmetric laser interferometer type long-distance detection demodulation system and disturbance positioning method, including two lasers, Mach-Zehnder fiber interferometer, data acquisition card and industrial computer, two lasers provide the narrow linewidth light source of different central wavelength;Two light sources enter Mach-Zehnder fiber interferometer in clockwise and counterclockwise direction respectively, two signal lights share the same sensing fiber link when detecting;A phase modulator introduces high-frequency carrier signal on a sensing fiber, and the corresponding sensing light signal is modulated with high-frequency carrier;Subsequently two sensing interference light signals enter industrial computer after erbium-doped fiber amplifier, dense wave division multiplexer, photodetector, data acquisition card, two interference sensing light signals are demodulated into phase information introduced by disturbance event by corresponding improved phase generation carrier algorithm respectively, and the specific position information of disturbance event acting on fiber link is analyzed by cross-correlation time delay estimation theory.

The invention discloses a central concave type multi-layer doped gain-balanced few-mode optical fiber structure, which is characterized in that each layer structure in an optical fiber is of a bull's-eye structure on the cross section of the optical fiber and shares the same center, and each layer sequentially comprises a low-refractive-index fiber core, a high-refractive-index fiber core, a groove and a cladding from inside to outside. According to the embodiment of the invention, a mode of combining a central concave type refractive index design and multi-layer doping is adopted, and overlapping integral factor differences among all transmission modes are reduced by adjusting distribution characteristics of all mode fields in the optical fiber, so that similar signal gains of all modes are realized, and a relatively excellent gain equalization characteristic of the amplifier is obtained. The optical fiber structure design can also increase the effective refractive index difference of each mode to a certain extent, reduce the coupling and crosstalk between the modes, and realize the high-purity gain of the few-mode optical fiber amplifier.

The invention relates to the technical field of metal defect detection, in particular to a GIS metal particle defect distributed detection system based on a multi-detection pulse type phi-OTDR, which comprises a narrow linewidth laser, a first coupler, a first acoustic optical modulator, a first erbium-doped optical fiber amplifier, a cyclic frequency shift loop, a circulator, a third coupler, a balanced photoelectric detector and an oscilloscope, the circulating frequency shift loop is used for performing frequency shift on the pulse light amplified by the first erbium-doped optical fiber amplifier and dividing the pulse light into n detection light pulses with different frequencies, and the detection light pulses are uniformly distributed among secondary pulse light output by the first erbium-doped optical fiber amplifier. According to the GIS metal particle defect distributed detection system based on the multi-detection pulse type phi-OTDR, the original pulse light is expanded into a plurality of detection light pulses with different frequencies through the circulating frequency shift loop, the Rayleigh scattering light aliasing problem does not need to be considered, and the contradiction that the light pulse frequency and the sensing optical fiber length cannot be obtained at the same time is solved; the detection precision is improved.

The invention relates to a multi-component gas sensing system based on a D-type optical fiber array. The system is characterized in that a femtosecond pulse mode-locked laser emits a femtosecond pulse sequence, the femtosecond pulse sequence is subjected to beam splitting processing through a first optical fiber coupler, and a first femtosecond pulse sequence and a second femtosecond pulse sequence are output; the third optical fiber coupler is used for carrying out beam splitting processing on the second femtosecond pulse sequence and outputting each path of femtosecond pulse sequence to pass through a corresponding optical fiber filter, a polarization controller, an electric delay line and a functionalized D-type optical fiber; the fourth optical fiber coupler is used for combining all the received femtosecond pulse sequences and outputting a sixth femtosecond pulse sequence; the second optical fiber coupler is used for combining all the received femtosecond pulse sequences and outputting a seventh femtosecond pulse sequence to the computer through the dispersion element, the front optical fiber amplifier, the optical fiber attenuator, the photoelectric detector and the A / D acquisition equipment, so that a multi-component gas detection result is obtained. And high sensitivity, high selectivity and rapid detection of multi-component gas detection can be realized.

This invention relates to distributed fiber optic sensing systems. A phase-tunable three-terminal coupled φ-OTDR measurement device based on a Sagnac interferometer is disclosed, comprising: a first pulsed light source, a first optical circulator, a sensing fiber, a continuous fiber amplifier module, a second optical circulator, a 3×3 optical coupler, a Sagnac ring, a semiconductor optical amplifier, a 1×2 optical coupler, a second pulsed light source, a second acousto-optic modulator, a first photodetector, a second photodetector, a third photodetector, and a data acquisition card. This invention achieves phase demodulation of different vibration signals by setting a semiconductor optical amplifier in the Sagnac ring and adjusting the phase difference between two signals by regulating the intensity of the control beam. Furthermore, it effectively avoids the problem of reduced spatial resolution caused by path difference between two signals in Michelson or Mach-Zehnder interferometers.

A kind of weak reflection grating array reflectivity measurement method, using optical time domain reflectometer OTDR, including direct current light source, modulator, erbium-doped fiber amplifier, circulator, photoelectric detector, data acquisition card, data analysis processing module and display module;1) weak reflection grating array is accessed to above-mentioned measurement system, the weak reflection grating array to be measured is accessed to the second port of circulator;2) the output port of laser is connected with the input port of modulator;Laser output direct current light signal is modulated into probe light pulse by modulator, is amplified after being amplified by erbium-doped fiber amplifier, forms probe signal by entering the weak reflection grating array to be measured through circulator;3) the input port of photoelectric detector is connected with the third port of circulator;The input port of data acquisition card is connected with the output port of photoelectric detector;It is sent to data acquisition card by photoelectric detector output port;4) the output port of data acquisition card is connected with data analysis processing module.

The invention discloses an all-fiber high-power narrow-linewidth laser long-distance transmission system and method. The system comprises a narrow-linewidth laser, a pumping source, a pumping beam combiner, a gain fiber, a cladding light stripper, a coupling device, a double-core fiber and an output device. The laser outputs initial laser, the initial laser and pumping source light are injected into the gain optical fiber through the beam combiner to form high-power laser, the stripper removes residual pumping light, the coupling device guides the laser into the double-core optical fiber, the laser is periodically coupled between fiber cores to disperse power density and suppress stimulated Brillouin scattering, and finally the laser is shaped and output through the output device. System devices are connected through an optical fiber fusion splicer, a passive double-core optical fiber is replaced by an active double-core optical fiber and can be applied to an optical fiber amplifier, and long-distance stable transmission is achieved.

This utility model belongs to the technical field of fiber optic amplifier equipment, specifically relating to a C-band few-mode erbium-doped fiber amplifier, comprising: an input-end few-mode pigtail, an input-end few-mode to single-mode mode field adapter, an input-end single-mode isolator, a single-mode wavelength division multiplexer, a single-mode pump, a single-mode erbium-doped fiber, an output-end single-mode isolator, an output-end single-mode to few-mode mode field adapter, and an output-end few-mode pigtail; wherein, the input-end few-mode pigtail, the input-end few-mode to single-mode mode field adapter, the input-end single-mode isolator, the single-mode wavelength division multiplexer, the single-mode erbium-doped fiber, the output-end single-mode isolator, the output-end single-mode to few-mode mode field adapter, and the output-end few-mode pigtail are sequentially connected by fiber optic fusion splicing; the single-mode pump and the single-mode wavelength division multiplexer are connected by fiber optic fusion splicing.

The invention discloses a distributed multi-parameter sensing system and method combined with an optical transceiving integrated chip, and relates to the field of distributed optical fiber sensing, and the system comprises a temperature control optical transceiving assembly, an arbitrary waveform function generator, an upper computer, a multi-channel data acquisition instrument, an erbium-doped optical fiber amplifier, a circulator and a sensing optical fiber. The temperature control light transmitting-receiving assembly comprises a semiconductor temperature controller and a light transmitting-receiving integrated chip; the optical transceiver integrated chip comprises a tungsten copper substrate, a thin film circuit, an output single-mode fiber, a semiconductor amplifier chip, a semiconductor laser chip, an avalanche photoelectric detector chip, a photon lead waveguide structure and an input single-mode fiber. Through optical transceiver chip integration, a cooperative control structure and a related signal processing algorithm, distributed sensing with compact structure, multi-parameter synchronous decoupling and high precision coexistence is realized.

The application discloses a kind of distributed optical fiber monitoring and early warning systems for measuring buried pipeline damage, and relates to pipeline detection technical field.The distributed optical fiber detection module and monitoring and early warning module are included, the distributed optical fiber detection module includes, laser, first polarization maintaining coupler, first photoelectric modulator, erbium-doped fiber amplifier, polarization scrambler, first coupler, circulator, second polarization maintaining coupler, second photoelectric modulator, acoustooptic modulator, second coupler and sensing optical fiber;Detection and early warning module includes, photoelectric detector, first filter, second filter, central processing unit and display early warning terminal.The application obtains two different scattering signals by using first filter and second filter, detects the damage condition of buried pipeline by two detection methods, improves the detection accuracy of distributed optical fiber detection module, and can display the detection state by display early warning terminal and timely warning.

The invention discloses a water vapor concentration detection method, device and equipment and a medium, relates to the technical field of atmospheric environment monitoring, and is applied to a laser radar comprising a laser conversion assembly. The method comprises the following steps: generating first original laser and second original laser; the water vapor absorbance of the first original laser is far greater than that of the second original laser; processing the first original laser and the second original laser by using an optical fiber amplifier and a frequency doubling crystal in the assembly to obtain first target laser and second target laser; the first target laser and the second target laser are emitted to the atmosphere, and a first echo signal and a second echo signal which are reflected back are received; and filtering an environment interference signal in the first echo signal based on the second echo signal, and determining the water vapor absorption intensity of the first target laser according to the differential signal ratio and the first target laser so as to determine the water vapor concentration information in the atmosphere. And more accurate water vapor concentration detection can be carried out.