92 results about "Fiber coupler" patented technology

The invention provides an all-polarization-maintaining optical fiber mode-locked laser which comprises a linear cavity and an annular cavity. Wherein the annular cavity consists of a wavelength division multiplexer, an optical fiber coupler, a phase bias device, a gain optical fiber and a dispersion compensation optical fiber; the linear cavity is composed of an optical fiber coupler and an optical fiber reflector. As a function multiplexing device, an external electric field is applied to the phase bias device, so that the functions of continuous tuning of the phase difference in the positive direction and the negative direction in the annular cavity of the 9-shaped cavity mode-locked fiber laser and rapid phase tuning are realized, and the realization of a mode-locked state and a high-precision phase locking state is promoted. In addition, the composition structure of the resonant cavity can be simplified, and the repetition frequency and the system stability of the mode-locked laser can be improved. The technology for constructing the 9-shaped cavity mode-locked fiber laser by adopting the active phase bias device has originality in the field of ultrafast optics, and a better choice is provided for the all-polarization-maintaining fiber mode-locked laser.

The invention discloses a near-infrared wide-spectrum pulse light source generator, belongs to the technical field of laser light source manufacturing, and aims to solve the problems of complex system structure and high cost due to the fact that a supercontinuum laser generates supercontinuum through multi-stage power amplification in the prior art. The device is composed of a first semiconductor pump laser, a first wavelength division multiplexer, a first gain optical fiber, a first filter, a first dispersion compensation optical fiber, a first high-nonlinearity optical fiber, a first isolator, an optical fiber coupler, a second semiconductor pump laser, a second wavelength division multiplexer, a second gain optical fiber, a second filter, a second dispersion compensation optical fiber, a second high-nonlinearity optical fiber and a second isolator. According to the invention, the characteristic of high mode-locked pulse energy of the Mmyshev oscillator is utilized, multi-stage power amplification is not needed, and the super-continuum spectrum can be directly generated, so that the system structure is simplified, and the cost is reduced; the laser light source can be applied to multiple fields of laser sensing, photoelectric countermeasure, remote sensing detection, optical imaging and the like.

The application discloses a quantum random number generator based on feedback adjustment of a comparator threshold value and a random sequence generation method. The quantum random number generator comprises a superluminescent diode, a filter, an erbium-doped fiber amplifier, a fiber coupler with a coupling ratio of 50:50, an optical delay line, a first beam splitter and a second beam splitter with the same splitting ratio, a first optical power meter and a first photodetector connected with the first beam splitter, a second optical power meter and a second photodetector connected with the second beam splitter, a microcontroller connected with the first optical power meter and the second optical power meter, and a comparator connected with the microcontroller, the first photodetector and the second photodetector. The first photodetector and the second photodetector are connected with the comparator through a differential circuit. The application adjusts the threshold voltage to offset the influence of the output characteristics of a light source on the output random number.

Described herein are systems and techniques for providing photonic devices having efficient optical coupling between waveguides and optical fibers. The photonic devices comprise an edge coupler disposed within a cavity of a photonic integrated circuit (PIC) and a pluggable assembly removably coupled with the edge coupler. The PIC includes a spot size converter optically coupled to a waveguide to expand light received from the waveguide prior to exiting the PIC.

The invention relates to a weak pressure measurement method and system based on film reflection, the system comprises a light source, an optical fiber pressure probe, a signal acquisition module, a signal processing module and a signal display module, the optical fiber pressure probe comprises a film, a dual-optical fiber coupler and a sleeve, and the signal acquisition module comprises a photosensitive transistor and a driving circuit. And the signal processing module comprises a signal amplification circuit and a signal demodulation circuit. The method comprises the steps that when light beams emitted by the light source are projected to the surface of the film through the emission optical fiber, the film deforms under the action of external pressure, reflection light spot distribution and reflection angle change are caused, and signal modulation is achieved. The emergent optical fiber receives the reflected signal, the signal acquisition module acquires a light intensity signal of the emergent optical fiber and converts the light intensity signal into an electric signal, the signal processing module amplifies and processes the acquired information to realize signal demodulation, and the signal display module displays a processing result. The micro-pressure sensor has the advantages that micro-pressure measurement with low cost and excellent linearity is realized through a simple zero-point adjustment mechanism and a compact double-optical-fiber design.

The present application relates to the technical field of measurement, in particular to a kind of spectrometer automatic calibration device and method, comprising: light source, optical isolator, fiber coupler, standard reference light source, adjustable fiber attenuator, first fiber collimator, holographic frequency selection module, electric reflector, volume holographic grating, second fiber collimator, beam splitter, optical interface unit, to be measured spectrometer, photoelectric detector, electric reflector driver, angle-second level angle encoder, control module, communication module, computer and image display unit.The present application utilizes volume holographic grating to select the corresponding relationship between the pixel of spectrometer and wavelength, can continuously select monochromatic light, and the theoretical resolution is consistent with the spectral resolution of light source;Using automatic calibration method, the automatic calibration of spectrometer is realized, pixel-wavelength calibration data can be automatically generated and stored in preset format, which is convenient for automatic calibration and data processing of spectral measurement software, and realizes wavelength-pixel position registration at pixel level.

The application discloses a kind of rock mechanics test in the collection device of acoustic emission signal, including computer, measurement and control and signal processing equipment, distributed acoustic wave sensing equipment and collection probe: the collection probe is composed of single-mode optical fiber and probe skeleton, single-mode optical fiber is fixed around probe skeleton, when testing, collection probe is fixed on the surface of rock sample for testing;The measurement and control and signal processing equipment include: radio frequency amplifier, digital-to-analog conversion module, analog-to-digital conversion module, filter amplifier, field programmable logic gate array and CPU-GPU data processing module;The distributed acoustic sensing equipment includes narrow linewidth laser, fiber coupler, acoustooptic modulator, erbium-doped fiber amplifier, circulator, polarization diversity receiver, first balanced photodetector and second balanced photodetector;Collection signal band is wide, can be conveniently installed on any rock sample.Collecting main frequency is lower, collection probe is connected closely with rock sample, coupling is good, without additional smearing coupling agent.

An interferometric quadrature detection system is disclosed that combines a reference or local oscillator signal with a sample or modulated signal in a fused fiber coupler having at least three outputs to generate phase-shifted signals. The phase-shifted signals are processed using either additional fused fiber couplers with balanced photoreceivers or single-ended photodetectors with subsequent analog subtraction to generate differential signals. The differential signals are used to reconstruct a complex-valued representation of the interferometric signal, enabling unambiguous recovery of amplitude and phase at or near the shot-noise limit. The disclosed methods and apparatus provide fiber-based alternatives to integrated optical hybrids and are applicable in optical coherence tomography, interferometric sensing, coherent optical communication systems and other applications.

A multi-core fiber coupler based on single-clad optical fibers (1), and a taper ratio design method therefor. Each single-clad optical fiber (1) comprises a fiber core (13), a cladding (12), and a coating layer (11), arranged in sequence from inside to outside. The multi-core fiber coupler based on single-clad optical fibers (1) comprises single-clad optical fibers (1) and a sleeve (2). Several single-clad optical fibers (1) are nested within the sleeve (2), and the total number of the single-clad optical fibers (1) is equal to the total number of fiber cores in a target multi-core optical fiber (3). One end of the sleeve (2) is tapered, and the other end is not tapered. A mode field diameter of each single-clad optical fiber (1) at the non-tapered end of the sleeve (2) matches a mode field diameter of a single fiber core of the target multi-core optical fiber (3). The single-clad optical fibers (1) and the multi-core fiber coupler have the advantages of low fabrication difficulty, low cost, and the capability of achieving low-loss connection with multi-core optical fibers and standard single-mode optical fibers.

The application relates to a mechanical hand control dispensing field, and discloses a feature recognition guide mechanical hand dispensing method, a computing device and a storage medium, the method comprises the following steps: recognizing a fiber coupler part feature according to a camera shooting tool plate image; when the part feature is identified as a taper area, a shearing pipe opening or a glass pipe opening, adjusting a light source according to a preset light adjustment condition corresponding to the taper area, the shearing pipe opening or the glass pipe opening, shooting a part image through the camera, and recognizing pixel coordinates of the taper area, the shearing pipe opening or the glass pipe opening according to the image; calculating dispensing coordinates of a mechanical hand according to the pixel coordinates of the taper area center, the pixel coordinates of the shearing pipe opening and the pixel coordinates of the glass pipe opening; and dispensing at the dispensing coordinate point through the mechanical hand control dispensing machine, the application adjusts the light source and the camera parameter matched with different part features of the coupler based on different part features, accurately recognizes the coordinates of the different part features, calculates the accurate dispensing coordinates of the mechanical hand, and improves the dispensing accuracy and the dispensing efficiency.

This invention discloses a fiber Bragg grating level sensor based on liquid pressure conversion, comprising a fiber Bragg grating demodulator, a 2×1 fiber coupler, a transmission fiber, and a sensing unit. The sensing unit consists of a strain-sensing fiber Bragg grating, a temperature-compensated fiber Bragg grating, a sealed cylinder, a support beam, a pressure block, a pressure tension frame, a sealing membrane, and a stop. The pressure block and the pressure tension frame convert liquid level changes into longitudinal displacement changes, causing axial strain in the strain-sensing fiber Bragg grating. This results in a drift in the center wavelength of the strain-sensing fiber Bragg grating, and the liquid level height of the container is measured by monitoring this wavelength change. This invention eliminates the influence of temperature on the liquid level measurement results through a temperature-compensated fiber Bragg grating, offering advantages such as a large measurement range, good practicality, simple structure, low cost, good stability, high sensitivity, and safety and reliability, meeting the needs of measuring liquid levels in large storage tanks and other applications.

The application relates to a fast demodulation system and method for a large-scale microcavity array on a chip, and the system comprises a frequency-sweeping laser, a first fiber coupler, a microcavity array transmission signal arm, an auxiliary interference reference arm, a same-frequency trigger arm and a signal processing device. The first fiber coupler is used for dividing a light source into a first light source and a second light source. The microcavity array transmission signal arm is used for receiving the first light source of the frequency-sweeping laser, and the first light source enters a large-array microcavity sensor device after polarization processing, and is converted into an electric signal after receiving the disturbance of an external sensing signal. The auxiliary interference reference arm is used for receiving the second light source of the frequency-sweeping laser, and two beams of coherent light with opposite phases are obtained after processing the second light source, and then the coherent light is converted into an electric signal. The same-frequency trigger arm is used for transmitting a same-frequency trigger signal emitted by the frequency-sweeping laser. The signal processing device is used for signal acquisition and processing. The application effectively suppresses the frequency-axis distortion and spectral line broadening caused by the frequency-sweeping nonlinearity of the laser, and can be applied to the accurate demodulation of a large-scale, high-Q microcavity sensing array.

The application relates to an all-fiber variable carrier laser sound field measuring device and a variable carrier modulation method, and relates to the technical field of laser application. The device comprises a main laser, a third fiber coupler, a fiber attenuator, a second fiber coupler, a balanced photoelectric detector, a signal acquisition card and an industrial computer; the third fiber coupler is further connected with an optical phase-locked loop; the optical phase-locked loop comprises the following components connected in sequence: a first fiber coupler, a phase detector, a signal amplifier, a frequency mixer, a voltage-controlled oscillator and a slave laser; wherein the frequency mixer is further connected with a local oscillator. The all-fiber laser coherent vibration measuring light path is adopted as the light path structure of the spatial sound field measuring system, can be disassembled and simply installed, and all the light paths are transmitted through optical fibers, so that the influence of ambient light can be avoided. The fiber attenuator in the local light path can adjust the attenuation coefficient in real time according to factors such as a detection distance and a detection angle, and the matching efficiency of the local light and the signal light is greatly improved.

The application relates to the technical field of optical communication, in particular to a three-dimensional waveguide chip, a preparation method thereof and a single-multiple core optical fiber coupler. The three-dimensional waveguide chip comprises a plurality of optical waveguides with equal diameters, an integrated fiber core bundle, a first end of the fiber core bundle is composed of linear arrangement of the optical waveguides, and a second end of the fiber core bundle is composed of circumferential arrangement of the optical waveguides or composed of central and circumferential arrangement; a three-dimensional coordinate system is established with the center of the fiber core bundle at the first end as an origin, an extension direction of the first end to the second end as an x-axis, a linear arrangement direction of the optical waveguides as a z-axis, and a direction perpendicular to the x-axis and the z-axis as a y-axis; the coordinates of the optical waveguides satisfy the following formula: wherein L is a distance between the first end and the second end, a is a y value of the center of the optical waveguide at the second end, b is a difference between a z value of the optical waveguide at the first end and a z value of the optical waveguide at the second end, and c is the z value of the optical waveguide at the first end.

The application relates to a refractive index micro-ring sensor based on a multi-core fiber taper and a measuring method thereof. The refractive index micro-ring sensor based on the multi-core fiber taper mainly comprises a light source, a single-core fiber, a first multi-core fiber coupler, a multi-core fiber taper, a second multi-core fiber coupler and a spectrometer; the middle part of the multi-core fiber taper is smaller than the two ends, so that a fiber taper area is formed in the middle part of the multi-core fiber, and a micro-ring is formed around the waist part of the fiber taper area; wherein: the output end of the light source is connected with one end of the single-core fiber; the other end of the single-core fiber is connected with one fan-in end of the first multi-core fiber coupler; the fan-out end of the first multi-core fiber coupler is connected with one end of the multi-core fiber; the other end of the multi-core fiber is connected with the fan-out end of the second multi-core fiber coupler; and one fan-in end of the second multi-core fiber coupler is connected with the spectrometer. Compared with the existing fiber refractive index sensor, the application has higher integration and improved sensitivity.

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.

The application relates to a liquid drop spraying device for an inertial particle dynamics experiment of an online cabinet of a space station, which comprises a fiber coupler, a spray head and a support, the fiber coupler and the spray head are both installed on the support, a light path channel and a liquid path channel are vertically arranged and cross arranged in the support, the spray head is coaxially installed at one end of the liquid path channel and communicates with the liquid path channel, and the other end of the liquid path channel is in an open structure; the fiber coupler is coaxially installed at one end of the light path channel and communicates with the light path channel, the intersection point of the central axis of the light path channel and the central axis of the liquid path channel is a light-liquid intersection point, and the liquid spraying end of the spray head is located above the light-liquid intersection point; the support comprises a support surface and an assembly surface, the spray head is installed on the support surface side of the support through a clamping assembly, the assembly surface of the support is used for assembling with a turbulent flow generating device, and the support surface and the assembly surface are arranged in parallel opposition or at an acute angle.

The application provides a self-calibration high-intensity optical fiber hydrophone based on an end face reflection principle and relates to the technical field of hydrophones.The application comprises the following steps: a laser light source emits a first laser beam, a fiber optical isolator inhibits reflection and outputs a second laser beam, a fiber adjustable optical attenuator adjusts incident power and outputs a third laser beam, a 1x2 fiber coupler divides the third laser beam into a fourth laser beam and a fifth laser beam, a first photoelectric detector monitors power, a fiber circulator transmits the fifth laser beam to a fiber sensing module, generates reflected light and transmits the reflected light to a second photoelectric detector, and the second photoelectric detector converts the reflected light into a voltage signal, a data acquisition card acquires the signal, a signal demodulation processing unit calculates sound pressure sensitivity according to a mapping relationship formula of the voltage signal and the sound pressure, and a standard voltage module provides a standard voltage for the data acquisition card.The application solves the problems that a high-intensity hydrophone cannot be reused and cannot be self-calibrated after being damaged in the prior art.

The invention provides an optical fiber hydrophone based on frequency domain multi-wavelength interference and a working method thereof. The device comprises a structure and an optical path part, in the structure part, a cylindrical measuring optical fiber (the cylindrical measuring optical fiber and a hollow cylindrical packaging body made of polyurethane sound transmission rubber form an integrated structure) for increasing the number of winding turns is packaged in the hollow cylindrical packaging body, and a reference optical fiber is wound outside a rigid supporting column; the light path part comprises a sweep frequency laser, an optical fiber coupler and other components, laser is transmitted to two optical fibers after being split by the coupler and is transmitted back and interfered after being collimated and focused by a convex lens and reflected by a reflector, and an interference signal is transmitted to a computer for data processing after being detected by a photoelectric detector. The device can detect weak low-frequency underwater acoustic signals.

The application discloses a kind of based on the principle of OFDR's double-pulse long-distance distributed vibration detection device, including narrow linewidth laser light source and to-be-measured interferometer, and the application also includes auxiliary interferometer and phase noise demodulation and elimination mechanism, narrow linewidth laser light source includes NLL laser and first fiber coupler, the first output channel and the second output channel of first fiber coupler are connected with to-be-measured interferometer and auxiliary interferometer respectively, and to-be-measured interferometer and auxiliary interferometer are connected with phase noise demodulation and elimination mechanism.The application uses the above structure based on the principle of OFDR's double-pulse long-distance distributed vibration detection device, utilizes two homologous pulses to carry out Rayleigh scattering detection, mixes with auxiliary interferometer, realizes the elimination of phase noise, breaks through the limit of coherence length to range, realizes long range, frequency response high vibration signal detection, and only needs to mix in optical path twice, demodulation algorithm is simple, and phase correction speed is fast.

A kind of vehicle-mounted ranging device and method, belong to distance detection technical field, device is by short coherence broadband light source, fiber coupler, wavelength division multiplexer, beam expander, optical splitter, lens, filter, area array camera and vehicle-mounted computer etc.; by vehicle-mounted computer real-time comparison two cameras image difference and the size of set threshold value, when vehicle-mounted computer determines that image difference is greater than threshold value, then it is explained that there is obstacle at the distance L in front of vehicle, vehicle-mounted computer issues alarm signal at this time.The present application adopts two light sources and two cameras, imaging twice in the same time, by the two images obtained are subtracted, eliminate interference fluctuation;The present application uses short coherence light interference technology, improves signal-to-noise ratio, can detect weak reflection signal;The present application selects broadband light source, longitudinal resolution is high, guarantees measurement accuracy while saves extra timing circuit;The present application uses area array camera to collect image, speed is fast, the number of imaging dot matrix is large, and lateral resolution is high.

The application provides a tunable laser fiber grating demodulator with high demodulation speed and a demodulation method, to solve the technical problems of complex calibration trigger algorithm, long time consumption, low sensing precision and slow demodulation speed in the prior art. The demodulator comprises a data acquisition and processing unit, a computer, a frequency sweeping laser unit connected in sequence, and a first fiber coupler, an HCN gas absorption chamber, a second fiber coupler, two second photoelectric converters, a fiber splitter, N fiber loopers, N-way fiber grating sensors and N first photoelectric converters. The inlet end of the HCN gas absorption chamber is connected with the output end of the first fiber coupler, to absorb P fixed wavelength lights output by the first fiber coupler and output wavelength absorption lines. The outlet end is connected with the two second photoelectric converters through the second fiber coupler. The two second photoelectric converters are both used for converting the wavelength absorption lines into pulse signals, and are used as trigger signals and calibration signals respectively.

This invention discloses a laser linewidth measurement device and method based on switchable channel delay self-heterodyne interferometry, belonging to the field of laser linewidth measurement technology. The laser to be measured is incident on a first fiber coupler via an isolator and splits into two paths: one path enters a computer-controlled first and second optical switches via a three-port fiber circulator, switching between different lengths of delay fiber via the first and second optical switches, rotating the polarization state by 90° via a Faraday rotating mirror before returning along the original path, and then restoring the original polarization state via a polarization controller; the other path undergoes frequency shifting via an acousto-optic frequency shifter. The two paths are combined via a second fiber coupler to generate a beat frequency optical signal, which is then acquired by a photodetector for photoelectric conversion and a spectrum analysis module. The computer fits the beat frequency power spectrum corresponding to different delay lengths to obtain the laser linewidth to be measured. This invention has strong anti-interference capabilities and can simultaneously acquire Lorentz linewidth, Gaussian linewidth, and composite linewidth, with a wide linewidth measurement range.

1. The name of the design product: polarization maintaining fiber coupler (68 channels). 2. The use of the design product: for splitting the optical signal in the input fiber into the signal in multiple output fibers. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view.

The application relates to the technical field of Raman spectrum detection, in particular to a laser-integrated immersion type Raman probe which comprises a shell and a cover plate, the front end of the shell is provided with an aluminum alloy probe pipe, the outer portion of the aluminum alloy probe pipe is sleeved with a quartz sleeve, the rear end of the quartz sleeve is connected with the shell through a quartz sleeve fixed adapter ring, the rear portion in the shell is provided with a laser, the middle portion in the shell is provided with a plane mirror, the shell is internally provided with a dichroic mirror, the front end of the aluminum alloy probe pipe is internally provided with a focusing lens, the shell is internally provided with a long-wave-pass filter, and the rear portion of the shell is provided with a fiber coupler; the laser is integrated to reduce light loss, the quartz sleeve is used to realize corrosion-resistant immersion type detection, multiple filters are arranged to improve the signal-to-noise ratio, and an adjustable mirror is arranged to reduce the assembly precision requirement.

This invention discloses a narrow-linewidth fiber laser system based on a self-injection locked feedback mechanism, belonging to the field of fiber optic communication. The system includes a main cavity, a self-injection locked feedback module, and an erbium-doped fiber amplifier. The main cavity internally includes a composite ring cavity filter for selecting longitudinal modes. This composite ring cavity filter is sequentially connected to a polarization controller, a first erbium-doped fiber, a first wavelength division multiplexer, a second erbium-doped fiber, and a first uniform fiber grating via a first circulator. The output of the first uniform fiber grating is connected to the input of a first fiber coupler. One output of the first fiber coupler is sequentially connected to a fiber delay line and a Faraday rotator in the self-injection locked feedback module, with the Faraday rotator rotating at a 90° angle. The other output of the first fiber coupler is connected to the input of the erbium-doped fiber amplifier. Through this structure, the present invention improves the stability of the laser system.

The invention discloses an ultra-narrow linewidth continuous wave low-noise fiber seed laser generation system. The system comprises a semiconductor pumping source, a single-mode wavelength division multiplexer, a phase shift Bragg fiber grating, a polarization-maintaining fiber circulator, a scattering fiber, a polarization-maintaining tunable fiber grating, a polarization-maintaining isolator, a dispersion compensation fiber, a semiconductor optical amplifier and a polarization-maintaining 12 fiber coupler. The system generates single-frequency laser through the phase shift Bragg fiber grating, realizes line width narrowing by combining distributed Bragg feedback based on Rayleigh scattering, improves output power by using the semiconductor optical amplifier, and effectively suppresses noise by combining the dispersion compensation fiber. According to the scheme, the ultra-narrow linewidth continuous wave low-noise optical fiber seed laser with high stability and high spectral purity can be realized, and the ultra-narrow linewidth continuous wave low-noise optical fiber seed laser has important application value, is suitable for a front-end light source of a high-quality optical fiber laser, and provides key support for the fields of precision measurement, coherent communication and the like.

1. The name of the design product: polarization maintaining fiber coupler (132 channels). 2. The use of the design product: for splitting the optical signal in the input fiber into the signal in multiple output fibers. 3. The design points of the design product: in shape. 4. The picture or photo that best shows the design points: design 1 perspective view. 5. Design 1 is designated as the basic design.

The application discloses a kind of fiber communication sensing integration system based on frequency-sweeping laser, including frequency-sweeping optical carrier generation and intensity modulation transmitting part, same optical fiber transmission part, remote direct detection communication receiving part and coherent Rayleigh backscattering sensing receiving part;The whole system is composed of frequency-sweeping laser, low-speed arbitrary function generator, polarization maintaining fiber coupler, Mach-Zehnder modulator, arbitrary waveform generator, electric amplifier, erbium-doped fiber amplifier, fiber optic circulator, fiber to be measured, adjustable optical attenuator, photodetector, data acquisition equipment one, coherent receiver, data acquisition equipment two.The system of the application is simple in structure, high in system integration degree, simple in communication receiving end structure, improved in communication transmission performance, and flexible optimization in sensing performance, suitable for different communication transmission distance and distributed sensing application scenarios.

The invention provides a multichannel distributed FMCW gas sensing device and method based on spatial light modulation, and relates to the technical field of spectrum diagnosis. The device comprises a tunable laser, an optical fiber coupler, a main interferometer, an auxiliary interferometer, a data acquisition card, a gas detection area and the like, wherein the gas detection area comprises a first gas pool, a second gas pool and a reflector group, and the gas detection area is arranged according to a distributed sensing mode and a multi-channel sensing mode; the main interferometer comprises a spatial light modulator, and the spatial light modulator modulates incident detection light into multiple independent light beams through phase regulation and control and emits the multiple independent light beams to a gas detection area according to a preset angle; an echo light signal returned from the gas detection area is combined with the reference light to generate a main interferometer beat frequency signal; the auxiliary interferometer beat frequency signal is used for non-linear correction of the main interferometer beat frequency signal. According to the invention, spatial multi-path distributed gas sensing can be realized.