CN111289019A - Long-distance large-capacity quasi-distributed sensing system based on optical fiber random laser - Google Patents
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- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/35306—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement
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- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
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- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/35383—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using multiple sensor devices using multiplexing techniques
- G01D5/35387—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using multiple sensor devices using multiplexing techniques using wavelength division multiplexing
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Abstract
The invention discloses a long-distance large-capacity quasi-distributed sensing system based on optical fiber random laser, which relates to the technical field of optical fiber sensing and comprises a pump laser with adjustable wavelength broadband, an isolator, a wave combination module, a spectrum analysis module, a sensing optical fiber and an optical Fiber Bragg Grating (FBG) sensor; the invention has the advantages of simple structure, long sensing distance and strong multiplexing capability. When the sensor is used, the pump laser is turned on, the output wavelength and the output power of the pump laser are adjusted, and the sensing quantity carried by the sensor at a specific position can be demodulated through the spectrum analysis module. The FBG sensors placed at different positions of the optical fiber can be selected by changing the output wavelength and the output power of the pump, and the change of the external physical quantity is reflected by the change of the wavelength of the currently selected FBG sensor.
Description
Technical Field
The invention relates to the field of optical fiber sensing, in particular to a long-distance large-capacity quasi-distributed sensing system based on optical fiber random laser.
Background
In 2007, random lasers are of two-dimensional or three-dimensional structures, and such random lasers have the disadvantages of poor output laser direction difference, poor output laser controllability, high lasing threshold and the like. To improve these shortcomings, researchers such as c.dematos realized random laser lasing in the fiber for the first time in 2007, realized directional output of random laser, and reduced the random laser geometry to quasi-one-dimensional. The most structurally significant difference between random lasers over conventional lasers is that they do not have a well-defined optical cavity as in conventional lasers, but rather a random scattering medium provides feedback for the generation of random laser light. The laser light generated by the fiber random laser is generated in the optical fiber, and the output spectrum is stable under different environments, so the fiber random laser is very suitable for long-distance sensing. To use the optical fiber random laser for sensing, the sensing function can be realized only by adding some sensing elements on the basis of the original structure. In 2012, prince south et al realized a first-order and second-order point sensing system based on random fiber lasers, and used FBG whose center wavelength is sensitive to temperature as a sensing element, and placed the sensing element at the far end of the fiber, to realize point sensing with a sensing distance of 100km, a threshold of about 1.4W, and optical signal-to-noise ratios of 20dB and 35dB, respectively. In the same year, Pinto et al proposed a point sensor capable of decoupling temperature and strain, in which the sensing elements were 2 FBGs placed at the distal end of the fiber, and the sensing distance was 11km, and consisted of 10km of single mode fiber and 1km of dispersion compensation fiber. However, the multiplexing capability of the sensing system based on the optical fiber random laser is limited by the flat region of the Raman gain bandwidth of the optical fiber, so that the multiplexing capability is very limited, and the coverage bandwidth of the sensor is about 5nm generally.
The optical fiber sensor has the advantages of long-distance transmission, electromagnetic interference resistance, large signal bandwidth, high sensitivity, high response speed, wide dynamic range, compact structure, suitability for use in high-temperature, corrosive or dangerous environments and the like. These advantages make optical fiber sensing widely used in high-speed rail, large civil construction, long-distance oil pipeline, long-distance air pipeline, military base, national defense border, sea island monitoring, power transmission system and other fields. In particular to a power transmission system, a high-voltage transmission line is used as an important component of a power supply system and mainly used for transmitting electric energy. The transmission line is different from other facilities of the electric power system, and is mainly characterized in that: the system is distributed in the field of the wasteland, and has the advantages of multiple points, long lines, wide area, and complicated conditions of geography, landform, surrounding environment, weather and the like of the lines. The areas where the optical fibers matched with the power transmission lines pass are usually bad in natural conditions and inconvenient in traffic. When optical transmission is limited, a relay station needs to be established, the site selection, construction and maintenance of the relay station are very difficult, a large amount of resources need to be consumed, and if the relay station is not properly disposed, the safe operation of a power system is directly threatened. Therefore, how to effectively extend the sensing distance and reduce the number of relay stations becomes a problem which needs to be solved urgently.
Disclosure of Invention
The invention aims to: the invention provides a long-distance large-capacity quasi-distributed sensing system based on optical fiber random laser, which can prolong the sensing distance of an optical fiber sensing system and improve the multiplexing capability of the optical fiber sensing system, and aims to solve the technical problems that when optical transmission is limited, the sensing distance is short and the number of relay stations needs to be increased in the optical fiber sensing matched with the existing high-voltage transmission line.
The invention specifically adopts the following technical scheme for realizing the purpose:
the utility model provides a long distance large capacity quasi-distributed sensing system based on optic fibre random laser which characterized in that: the optical fiber Bragg grating optical fiber wavelength multiplexing device comprises a wavelength-adjustable pump laser, an isolator, a wave-combining module, a spectral analysis module, a plurality of rolls of sensing optical fibers with different lengths and a plurality of optical fiber Bragg gratings with different central wavelengths, wherein an output port of the pump laser is connected with an input port of the isolator, an output port of the isolator is connected with the wave-combining module, and an input port of the spectral analysis module is connected with the wave-combining module;
adjusting the output power and the output wavelength of a pump laser, selecting random laser with a proper order for realizing different maximum sensing distances, and selecting a device capable of reflecting specific wavelength, such as a Fiber Bragg Grating (FBG), arranged at a specific position of an optical fiber as a current demodulation sensing unit;
the pump light enters the wave combining module through the isolator, the wave combining module can provide feedback for the generation of random laser, the pump light can be transmitted in the sensing optical fiber, the sensing optical fiber can provide feedback and gain for the generation of the random laser, and the spectral analysis module can record the wavelength of the random laser;
and adjusting the output power of the pump laser, lasing random laser when the pump power is higher than the threshold power, enabling the random laser with the sensing information to enter the spectral analysis module to be demodulated, and reversely deducing the physical quantity to be detected through the demodulated wavelength.
Specifically, the method comprises the following steps: the pumping output power changes, the random laser order changes, the maximum distance which can be sensed changes, and the maximum sensing distance increases along with the increase of the random laser order; by changing the pump output wavelength and output power, the active FBG in the fiber changes, causing the random laser wavelength used for sensing to change. Since the FBG wavelength variation reflects the variation of the external physical quantity, the variation of the physical quantity can be obtained by demodulating the FBG wavelength.
Furthermore, the wavelength output by the pump laser can be adjusted within the range of 1130 nm-1380 nm, and the power output by the pump laser can be adjusted.
Further, the output wavelength of the pump laser is adjusted to match the wavelength of the pump light with the central wavelength of the FBG placed at a specific position of the optical fiber.
Further, the wavelength range that the spectrum analysis module can demodulate covers all random laser wavelengths with sensing information.
The combining module may select appropriate devices according to actual requirements, for example, the combining module may include a wavelength division multiplexer and a fiber ring mirror, or the combining module may include a wavelength division multiplexer, two fiber ring mirrors with different center wavelengths, and a coupler.
The quasi-distributed sensing is a multipoint monitoring technology, wherein a sensing element Fiber Bragg Grating (FBG) is welded in an optical fiber, and the change of an external physical quantity is reversely deduced by monitoring the variation of the peak wavelength of the FBG reflection spectrum. The FBG is used for sensing and encoding the wavelength, so that the defects that the loss of an optical fiber connector and a coupler must be compensated by an intensity modulation sensor and the output power of a light source is unstable are overcome.
The FBG is a sensitive element with excellent performance, the peak wavelength of the FBG changes along with the change of physical quantities such as temperature, stress and the like, non-optical physical quantities can be converted into optical physical quantities by designing a sensitive structure, the optical measurement of the non-optical quantities is realized, and external parameters such as strain, pressure, temperature, wind direction, temperature and micro-vibration and the like are directly sensed by demodulating a wavelength signal of the FBG. In addition, the FBGs adopt wavelength coding, and can form a sensing network by connecting the FBGs in series or in parallel by utilizing multiplexing technologies such as wavelength division, time division, space division and the like, so that quasi-distributed networked measurement of physical quantities is realized, which is a major advantage of the fiber bragg grating sensing system.
The invention has the following beneficial effects:
1. the invention has simple structure, simple system operation, long sensing distance and high multiplexing capability. The laser source used for the long-distance quasi-distributed sensing system is a fiber random laser.
2. When the optical fiber sensing device is used, the pumping laser is turned on, the output wavelength and the output power of the pumping laser are adjusted, and the sensing quantity can be demodulated through the spectrum analysis module under the appropriate pumping output wavelength and the appropriate pumping output power. By changing the output wavelength and output power of the pump laser, the active FBG in the fiber changes, and the random laser wavelength used for sensing changes. Since the external physical quantities carried by different wavelengths are different, different physical quantities can be obtained after demodulation.
3. The quasi-distributed sensing is a multipoint monitoring technology, wherein a sensing element Fiber Bragg Grating (FBG) is welded in an optical fiber, and the change of an external physical quantity is reversely deduced by monitoring the variation of the peak wavelength of the FBG reflection spectrum. The FBG is used for sensing and encoding the wavelength, so that the defects that the loss of an optical fiber connector and a coupler must be compensated by an intensity modulation sensor and the output power of a light source is unstable are overcome.
Drawings
FIG. 1 is a block diagram of a long-distance large-capacity quasi-distributed sensing system based on optical fiber random laser according to the present invention;
FIG. 2 is a block diagram of a long-distance large-capacity quasi-distributed sensing system based on second-order random laser according to the first embodiment;
fig. 3 is a block diagram of a long-distance large-capacity quasi-distributed sensing system based on third-order random laser according to the second embodiment;
fig. 4 is a block diagram of a long-distance large-capacity quasi-distributed sensing system based on fourth-order random laser according to a third embodiment;
reference numerals: the device comprises a pump laser 1, an isolator 2, a spectrum analysis module 3, a wavelength division multiplexer 4, a single mode fiber 5, a fiber Bragg grating 6, a fiber loop mirror 7-1, a fiber loop mirror capable of reflecting 13XXnm wavelength 7-2, a fiber loop mirror capable of reflecting 14XXnm wavelength 8-1:99 FBG coupler 9, a broadband FBG and a wave combination module 10.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.
In the description of the embodiments of the present invention, it should be noted that the terms "inside", "outside", "upper", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships conventionally arranged when products of the present invention are used, and are only used for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements indicated must have specific orientations, be constructed in specific orientations, and operated, and thus, cannot be construed as limiting the present invention.
Example 1
As shown in fig. 1, the long-distance large-capacity quasi-distributed sensing system provided by this embodiment based on the fiber random laser is a quasi-distributed sensing system based on the second-order fiber random laser, where the first-order random laser frequency is shifted by about 13THz with respect to the pump light frequency, and the second-order random laser frequency is shifted by about 26THz with respect to the pump light frequency. The system comprises a wavelength-adjustable pump laser 1, an isolator 2, a spectrum analysis module 3, a wavelength division multiplexer 4, a plurality of rolls of single-mode optical fibers 5 with different lengths, 10 optical fiber Bragg gratings 6 with different central wavelengths and an optical fiber loop mirror 7. The wavelength division multiplexer 4 comprises a port 1, a port 2, a port 3 and a public port, an input port of the spectral analysis module 3 is connected with the port 1 of the wavelength division multiplexer 4, an output port of the isolator 2 is connected with the port 2 of the wavelength division multiplexer 4, the optical fiber loop mirror 7 is connected with the port 3 of the wavelength division multiplexer 4, the single-mode optical fibers are in 10 rolls in total, the serial numbers are 5-1 to 5-10 in sequence, and one end of the single-mode optical fiber 5-1 is connected with the public port 4 of the wavelength division multiplexer. The lengths of the single-mode optical fibers numbered 5-1 to 5-10 were 30km, 10km, and 10km, respectively, and the total length of the single-mode optical fiber was 120 km. The wavelength range that the fiber ring mirror 7 can reflect is 14 XXnm. The wavelength range that the spectral analysis module 3 can demodulate is 15 XXnm.
The working principle of the invention is as follows: the pump laser 1 is adjusted to output pump light with a wavelength of 1348nm, the pump light passes through the isolator 2, the wavelength division multiplexer 4 enters the single mode fiber 5, the pump light is transmitted in the single mode fiber 5, random Rayleigh scattering occurs when the pump light is transmitted in the fiber due to random fluctuation of the refractive index of the fiber, a part of Rayleigh scattering light is constrained by the fiber waveguide and is transmitted along the reverse direction of the fiber, called backward Rayleigh scattering light, the backward Rayleigh scattering provides random feedback for the generation of random laser, meanwhile, spontaneous Raman radiation is amplified under the influence of Raman gain of the pump light in the transmission process, multiple amplification generates first-order random laser, the first-order random laser enters the fiber loop mirror 7 through the wavelength division multiplexer 4 and is reflected by the fiber loop mirror 7, the reflected first-order random laser reenters the single mode fiber 5 through the wavelength division multiplexer 4 as new pump light to provide energy for the generation of second-order, the FBG6-1 with the central wavelength of 1527nm at the position of 30km provides feedback for the second-order laser light, the output power of the pump laser 1 is adjusted, the second-order random laser light is excited after the pump power is higher than a second-order threshold value, the second-order random laser light enters the spectrum analysis module 3 through the wavelength division multiplexer 4 to be demodulated, and the change of the external physical quantity can be reversely deduced through the demodulated wavelength. The output wavelength and the output power of the pump laser are changed, for example, the pump output wavelength is 1355nm, the wavelength of the first-order random laser and the wavelength of the second-order random laser are changed correspondingly, the second-order random laser is fed back by a Fiber Bragg Grating (FBG)6-3 with the central wavelength of 1536nm at the position of 50km, the wavelength demodulated by the spectral analysis module 3 is changed, and the obtained sensing quantity is changed.
Example 2:
as shown in fig. 2, the long-distance large-capacity quasi-distributed sensing system based on the fiber random laser is a quasi-distributed sensing system based on a third-order fiber random laser. Pump light wavelength 12XXnm, first order random laser wavelength 13XXnm, second order random laser wavelength 14XXnm, third order random laser wavelength 15 XXnm. The system comprises a wavelength-adjustable pump laser 1, an isolator 2, an optical fiber loop mirror 7-1 capable of reflecting 13XXnm wavelength, a 1:99 coupler 8, a plurality of rolls of single-mode optical fibers 5 with different lengths, 10 optical fiber Bragg gratings 6 with different central wavelengths, an optical fiber loop mirror 7-2 capable of reflecting 14XXnm wavelength, a wavelength division multiplexer 4 and a spectrum analysis module 3. The wavelength division multiplexer 4 comprises a port 1, a port 2, a port 3 and a public port, an optical fiber loop mirror 7-1 capable of reflecting 13XXnm wavelength is connected with the port 1 of the wavelength division multiplexer 4, an output port of the isolator 2 is connected with the port 2 of the wavelength division multiplexer 4, an optical fiber loop mirror 7-2 capable of reflecting 14XXnm wavelength is connected with the port 3 of the wavelength division multiplexer 4, and 99% of the end of the coupler 8 is connected with the public port of the wavelength division multiplexer 4. The 1% end of the coupler 8 is connected to the input port of the spectral analysis module 3. The single-mode optical fiber 5 has 10 rolls in total, the numbers are 5-1 to 5-10 in sequence, the lengths of the single-mode optical fibers with the numbers of 5-1 to 5-10 are 70km, 10km and 10km respectively, and the total length of the single-mode optical fiber is 160 km. The wavelength range that the spectral analysis module 3 can demodulate is 15 XXnm.
The working principle of the invention is as follows: adjusting the pump laser 1 to output pump light with 12XXnm, the pump light enters the single mode fiber through the isolator 2, the wavelength division multiplexer 4 and the coupler 8 and is transmitted in the single mode fiber, adjusting the output power of the pump laser 1, when the pumping power is higher than the first-order threshold value, the first-order random laser is excited and used as a new pumping source to provide energy for the excitation of the second-order random laser, when the pumping power is higher than the second-order threshold value, the second-order random laser is excited, and similarly, the second-order random laser is used as a new pumping source to provide energy for the excitation of the third-order random laser, the Fiber Bragg Grating (FBG)6 provides feedback for the excitation of the third-order random laser, when the pumping power is higher than the third-order threshold value, the third-order random laser is excited, enters the spectrum analysis module 3 through the coupler 8 to be demodulated, and the change of the external physical quantity can be reversely deduced through the demodulated wavelength.
Example 3:
referring to fig. 3, the long-distance large-capacity quasi-distributed sensing system based on the optical fiber random laser is a quasi-distributed sensing system based on a fourth-order optical fiber random laser. Pump light wavelength 11XXnm, first order random laser wavelength 12XXnm, second order random laser wavelength 13XXnm, third order random laser wavelength 14XXnm, fourth order random laser wavelength 15 XXnm. The system comprises a wavelength-adjustable pump laser 1, an isolator 2, a fiber loop mirror 7-1 capable of reflecting 13XXnm wavelength, a 1:99 coupler 8, a plurality of rolls of single-mode fibers 5 with different lengths, 10 fiber Bragg gratings 6 with different central wavelengths, a fiber loop mirror 7-2 capable of reflecting 14XXnm wavelength, a wavelength division multiplexer 4, a broadband 9 with 1280nm central wavelength, and a spectrum analysis module 3. Wherein, wavelength division multiplexer 4 include 1 port, 2 ports, 3 ports and common port, can reflect 13XXnm wavelength's optical fiber loop mirror 7-1 and wavelength division multiplexer 4's 1 port connection, isolator 2's output port and wavelength division multiplexer 4's 2 ports are connected, reflect 14XXnm wavelength's optical fiber loop mirror 7-2 and wavelength division multiplexer 4's 3 ports connection, the center wavelength is that broadband FBG9 one end of 1280nm is connected with wavelength division multiplexer 4 common port. The other end of the broadband FBG9 with a center wavelength of 1280nm is connected to 99% of the end of the coupler 8, and the 1% end of the coupler 8 is connected to the input port of the spectral analysis module 3. The single-mode optical fiber has 10 rolls in total, the numbers are 5-1 to 5-10 in sequence, the lengths of the single-mode optical fibers with the numbers of 5-1 to 5-10 are 110km, 10km and 200km of the total length of the single-mode optical fiber. The wavelength range that the spectral analysis module 3 can demodulate is 15 XXnm.
The working principle of the invention is as follows: the output wavelength and the output power of the pump laser 1 are adjusted, the FBG placed at the proper position of the optical fiber is selected as a sensing element, and the wavelength carrying the sensing information is demodulated through the spectral analysis module.
Claims (4)
1. The utility model provides a long distance large capacity quasi-distributed sensing system based on optic fibre random laser which characterized in that: the optical fiber grating optical fiber laser comprises a pump laser (1) with an adjustable wavelength broadband, an isolator (2), a wave combination module (10), a spectrum analysis module (3), a plurality of rolls of sensing optical fibers (5) with different lengths and a plurality of optical fiber Bragg gratings (6) with different central wavelengths, wherein an output port of the pump laser (1) is connected with an input port of the isolator (2), an output port of the isolator (2) is connected with the wave combination module (10), and an input port of the spectrum analysis module (3) is connected with the wave combination module (10);
adjusting the output power and the output wavelength of a pump laser (1), selecting random laser with a proper order for realizing different maximum sensing distances, and selecting a device which is placed at a specific position of an optical fiber and can reflect specific wavelength, such as an optical Fiber Bragg Grating (FBG), as a current demodulation sensing unit;
the pump light enters the wave combining module (10) through the isolator (2), the wave combining module (10) can provide feedback for the generation of random laser, the pump light can be transmitted in the sensing optical fiber (5), the sensing optical fiber (5) can provide feedback and gain for the generation of the random laser, and the spectral analysis module (3) can record the wavelength of the random laser;
and adjusting the output power of the pump laser (1), when the pump power is higher than the threshold power, lasing random laser, enabling the random laser with sensing information to enter the spectrum analysis module (3) to be demodulated, and reversely deducing the physical quantity to be detected through the demodulated wavelength.
2. The long-distance large-capacity quasi-distributed sensing system based on the optical fiber random laser as claimed in claim 1, wherein the wavelength of the output of the pump laser (1) is adjustable, the adjustment range is 1130 nm-1380 nm, and the power of the output of the pump laser (1) is adjustable.
3. The long-distance large-capacity quasi-distributed sensing system based on the optical fiber random laser as claimed in claim 1 or 2, wherein: and adjusting the output wavelength of the pump laser (1) to enable the wavelength of the pump light to be matched with the central wavelength of the FBG placed on the specific position of the optical fiber.
4. The long-distance large-capacity quasi-distributed sensing system based on the optical fiber random laser as claimed in claim 3, wherein: the wavelength range which can be demodulated by the spectrum analysis module (3) covers all random laser wavelengths with sensing information.
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