A heterogeneous grating array and distributed multi-parameter sensing system

Abstract

The application provides a heterogeneous grating array and a distributed multi-parameter sensing system, and belongs to the technical field of optical fiber sensing, and the heterogeneous grating array comprises: an optical fiber and a broadband grating and a narrowband grating which are staggered and inscribed on the optical fiber, the broadband grating is used for measuring vibration, and the narrowband grating is used for measuring temperature. According to the application, the broadband grating and the narrowband grating are staggered and inscribed on the optical fiber, so that the measurement of two physical parameters, temperature and vibration, can be realized through one optical fiber, that is, the single-cable multi-parameter measurement is realized, and the universality of the application scene of the heterogeneous grating array is improved. Moreover, through the staggered inscription of the broadband grating and the narrowband grating, the global measurement of the two parameters, vibration and temperature, can be realized.

Description

Technical Field

[0001] This invention relates to the field of grating sensing technology, specifically to a heterogeneous grating array and a distributed multi-parameter sensing system. Background Technology

[0002] Distributed sensing technology based on fiber Bragg gratings utilizes gratings and optical signals as sensing elements and signal transmission media. When external physical parameters (such as temperature and vibration) change, the effective refractive index and grating period of the grating in the vicinity also change, leading to changes in information such as optical signal intensity and phase. Fiber Bragg grating arrays can realize high-capacity, long-distance quasi-distributed fiber optic sensing, possessing enormous application prospects and value, and can replace various electrochemical sensors in major engineering applications.

[0003] Although distributed fiber optic sensing technology has been widely adopted, many more applications require the simultaneous detection of temperature and vibration signals in engineering applications, posing challenges to the integration and reuse of distributed sensing technology based on grating arrays. Furthermore, in some complex and harsh production environments (such as oil exploration and long-distance track monitoring and security), limited resources make it difficult to simultaneously deploy multiple fiber optic cables and sensors to achieve simultaneous measurement of multiple parameters.

[0004] Therefore, there is an urgent need to provide a heterogeneous grating array and a distributed multi-parameter sensing system to realize multi-parameter measurement of a single optical cable, so as to improve the versatility of grating array applications. Summary of the Invention

[0005] In view of this, it is necessary to provide a heterogeneous grating array and a distributed multi-parameter sensing system to solve the technical problem in the prior art that it is impossible to achieve multi-parameter measurement with a single optical cable.

[0006] On the one hand, in order to solve the above-mentioned technical problems, the present invention provides a heterogeneous grating array, including an optical fiber and broadband gratings and narrowband gratings interleaved on the optical fiber, wherein the broadband grating is used to measure vibration and the narrowband grating is used to measure temperature.

[0007] In one possible implementation, the broadband grating and the narrowband grating are inscribed at equal intervals.

[0008] In one possible implementation, the 3dB bandwidth of the broadband grating is 1548.71nm~1552.99nm, and the center wavelength of the narrowband grating is 1550.79nm.

[0009] On the other hand, the present invention also provides a distributed multi-parameter sensing system, including an optical signal generation module, a heterogeneous grating array, and a signal processing module;

[0010] The optical signal generation module is used to generate tunable pulsed light sequences and continuous intrinsic light;

[0011] The heterogeneous grating array is used to generate a reflected pulse light signal based on the tunable pulse light sequence;

[0012] The signal processing module is used to process the reflected pulse light signal and the continuous intrinsic light to obtain vibration measurement results and temperature measurement results.

[0013] Wherein, the heterogeneous grating array is any of the heterogeneous grating arrays described in any of the above possible implementations.

[0014] In one possible implementation, the optical signal generation module includes a tunable laser, a first fiber coupler, an electro-optic modulator, a waveform generator, and a circulator.

[0015] The tunable laser is used to generate a continuous sweep beam and multiple trigger signals in a stepping mode.

[0016] The first fiber coupler is used to separate the continuously swept light into intrinsic light and measurement light;

[0017] The waveform generator generates a sequence of sinusoidal pulse electrical signals with increasing frequency in response to the trigger signal;

[0018] The electro-optic modulator is used to modulate the measurement light based on the sinusoidal pulse electrical signal sequence to generate the tunable pulse light sequence;

[0019] The circulator is used to input the tunable pulse light sequence into the heterogeneous grating array.

[0020] In one possible implementation, the number of signals in the sinusoidal pulse electrical signal sequence is:

[0021]

[0022] In the formula, N The number of signals in the sinusoidal pulse electrical signal sequence; It represents the frequency difference between two adjacent signals in a sinusoidal pulse electrical signal sequence; F The step size in the stepping mode of the tunable laser is expressed in GHz.

[0023] In one possible implementation, the optical signal generation module further includes an amplifier disposed between the electro-optic modulator and the circulator; the amplifier is used to amplify the tunable pulsed light sequence.

[0024] In one possible implementation, the signal processing module includes a second fiber optic coupler, a photodetector, a balanced photodetector, and a data acquisition card;

[0025] The first fiber coupler is used to divide the reflected pulse light signal into a first reflected pulse photon signal and a second reflected pulse photon signal;

[0026] The photodetector is used to convert the first reflected pulse photon signal into an electrical signal;

[0027] The balanced photodetector is used to perform coherent beat frequency processing on the second reflected pulse photon signal and the intrinsic light to generate a beat frequency signal;

[0028] The data acquisition card is used to obtain the temperature measurement result based on the plurality of trigger signals and the electrical signal, and to generate the vibration measurement result based on the plurality of trigger signals and the beat frequency signal.

[0029] In one possible implementation, the signal processing module further includes a signal energy determination unit, which is used to determine the optical signal energy of the reflected pulse optical signal and to determine the first reflected pulse photon signal and the second reflected pulse photon signal in the reflected pulse optical signal based on the optical signal energy and an energy threshold.

[0030] In one possible implementation, the data acquisition card includes a demodulation unit and a splicing unit;

[0031] The demodulation unit is used to demodulate the electrical signal and the beat frequency signal respectively, thereby obtaining a plurality of first demodulated signals and a plurality of second demodulated signals;

[0032] The splicing unit is used to splice the plurality of first demodulated signals and the plurality of second demodulated signals based on the plurality of trigger signals respectively, so as to obtain the temperature measurement result and the vibration measurement result.

[0033] The beneficial effects of the present invention are: the heterogeneous grating array provided by the present invention can realize the measurement of two physical parameters, temperature and vibration, through a single optical fiber by interlacing broadband gratings and narrowband gratings on the optical fiber, that is, realize multi-parameter measurement of a single optical cable, thereby improving the wide range of application scenarios of heterogeneous grating arrays.

[0034] Furthermore, by setting up alternating wideband and narrowband gratings, the present invention can achieve full-range measurement of the two parameters of vibration and temperature. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of an embodiment of the heterogeneous grating array provided by the present invention;

[0037] Figure 2 A schematic diagram of an embodiment of the distributed multi-parameter sensing system provided by the present invention;

[0038] Figure 3 A schematic diagram of a specific embodiment of the distributed multi-parameter sensing system provided by the present invention;

[0039] Figure 4 A schematic diagram of the signal during the generation of a tunable pulsed light sequence by the optical signal generation module provided by the present invention;

[0040] Figure 5 The arrangement of electrical signals and beat frequency signals acquired by the data acquisition card provided by this invention;

[0041] Figure 6 This is a schematic diagram of an embodiment of the present invention for splicing vibration signals. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0043] It should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this invention illustrate operations implemented according to some embodiments of the invention. It should be understood that the operations in the flowcharts may be implemented out of order, and steps without logical contextual relationships may be reversed or performed simultaneously. Furthermore, those skilled in the art, guided by the content of this invention, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor systems and / or microcontroller systems.

[0044] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0045] This invention provides a heterogeneous grating array and a distributed multi-parameter sensing system, which are described below.

[0046] Figure 1 This is a schematic diagram of an embodiment of the heterogeneous grating array provided by the present invention, as shown below. Figure 1 As shown, the heterogeneous grating array 100 includes: an optical fiber 110 and a broadband grating 120 and a narrowband grating 130 interleaved on the optical fiber 110. The broadband grating 120 is used to measure vibration, and the narrowband grating 130 is used to measure temperature.

[0047] Among them, fiber 110 is a single-mode fiber, which has good transmission performance and a wide bandwidth.

[0048] Specifically, the broadband grating 120 is a chirped broadband grating.

[0049] The principle of temperature measurement is as follows: The drift of the grating's center wavelength has a linear relationship with changes in external temperature. Based on this temperature sensitivity of the grating, the temperature at each grating position on the grating array can be monitored in real time online. In other words, temperature measurement is achieved by detecting changes in the grating's center wavelength and using wavelength demodulation.

[0050] The principle of vibration measurement is as follows: The vibration signal at various locations is sensed by utilizing the vibration-sensitive characteristics of the optical fiber between adjacent gratings. Specifically, the vibration magnitude is measured by utilizing the linear relationship between phase change and external strain change, along with the sensitivity. In other words, vibration measurement is achieved through coherent detection by detecting the phase difference between adjacent broadband gratings.

[0051] Compared with the prior art, the heterogeneous grating array 100 provided in this embodiment of the invention can realize the measurement of two physical parameters, temperature and vibration, through a single optical fiber by interlacing broadband gratings 120 and narrowband gratings 130 on optical fiber 110. That is, it realizes multi-parameter measurement of a single optical cable, thereby improving the wide range of application scenarios of the heterogeneous grating array 100.

[0052] Furthermore, by setting broadband gratings and narrowband gratings to be alternately inscribed, embodiments of the present invention can achieve full-range measurement of the two parameters of vibration and temperature.

[0053] Since the grating array is fabricated by writing with a mask, and the current masks are set at equal intervals, in order to reduce the difficulty of the heterogeneous grating array 100, in some embodiments of the present invention, the broadband grating 120 and the narrowband grating 130 are written at equal intervals.

[0054] By setting the broadband grating 120 and the narrowband grating 130 to be written at equal intervals, the heterogeneous grating array 100 can be obtained by simply using an existing mask during fabrication, which reduces the fabrication difficulty.

[0055] In a specific embodiment of the present invention, the 3dB bandwidth of the broadband grating 120 is 1548.71nm~1552.99nm, and the center wavelength of the narrowband grating 130 is 1550.79nm.

[0056] To achieve actual measurement of the heterogeneous grating array 100, this invention also provides a distributed multi-parameter sensing system, such as... Figure 2 As shown, the distributed multi-parameter sensing system 10 includes an optical signal generation module 200, a heterogeneous grating array 100, and a signal processing module 300.

[0057] The optical signal generation module 200 is used to generate tunable pulsed light sequences and continuous intrinsic light;

[0058] Heterogeneous grating array 100 is used to generate reflected pulse light signals based on tunable pulse light sequences;

[0059] The signal processing module 300 is used to process the reflected pulse light signal and the continuous intrinsic light signal to obtain vibration measurement results and temperature measurement results;

[0060] The heterogeneous grating array 100 is the heterogeneous grating array in any of the above embodiments.

[0061] In this embodiment of the invention, a light signal generation module 200 is set up to provide a tunable pulse light sequence for the heterogeneous grating array 100, and a signal processing module 300 is set up to process the reflected pulse light signal generated by the heterogeneous grating array 100, so as to obtain vibration measurement results and temperature measurement results, and realize the practical measurement application of the heterogeneous grating array 100.

[0062] To improve the accuracy of vibration and temperature measurement results, in some embodiments of the present invention, such as... Figure 3 As shown, the optical signal generation module 200 includes a tunable laser 210, a first fiber coupler 220, an electro-optic modulator 230, a waveform generator 240, and a circulator 250.

[0063] The tunable laser 210 is used to generate continuously swept light and multiple trigger signals in a stepping mode;

[0064] The first fiber coupler 220 is used to separate the continuous sweep light into intrinsic light and measurement light;

[0065] Waveform generator 240 generates a sequence of sinusoidal pulse electrical signals with increasing frequency in response to a trigger signal;

[0066] Electro-optic modulator 230 is used to modulate the measurement light based on a sinusoidal pulse electrical signal sequence to generate a tunable pulse light sequence;

[0067] Circulator 250 is used to input a tunable pulse light sequence into a heterogeneous grating array.

[0068] Specifically, the wavelength range of the continuously sweeping light generated by the tunable laser 210 is 1549nm~1552nm.

[0069] in, Figure 3 The dashed line with an arrow in the diagram represents the transmission process of the trigger signal.

[0070] This invention, through the use of a waveform generator 240 to generate a sequence of sinusoidal pulse electrical signals with increasing frequency, modulates multiple wavelengths of measurement light based on this sequence, generating a tunable pulse light sequence. This enables frequency division multiplexing and wavelength demodulation, allowing for more precise tracking of the center wavelength drift of the narrowband grating and improving temperature measurement accuracy. Furthermore, the first fiber coupler 220 divides the continuously swept light into intrinsic light and measurement light. The intrinsic light can be used for coherent demodulation in subsequent vibration measurements, achieving frequency division multiplexing and coherent detection phase demodulation. By utilizing multiple light pulses of different frequencies for detection and demodulation, the limitations of the Nyquist law can be overcome, significantly increasing the maximum detectable frequency range of the system and thus improving vibration measurement accuracy.

[0071] To improve the signal strength of the generated tunable pulse light sequence, in some embodiments of the present invention, the sinusoidal pulse electrical signal sequence generated by the waveform generator 240 is amplified by a voltage driver and then loaded onto the electro-optic modulator 230 to improve the signal strength of the generated tunable pulse light sequence, thereby improving the signal strength of the reflected pulse light signal generated by the heterogeneous grating array 100, which can improve the accuracy of vibration measurement results and temperature measurement results.

[0072] In a specific embodiment of the present invention, the number of signals in the sinusoidal pulse electrical signal sequence is:

[0073]

[0074] In the formula, N The number of signals in the sinusoidal pulse electrical signal sequence; It represents the frequency difference between two adjacent signals in a sinusoidal pulse electrical signal sequence; FThe step size is the step size in the stepping mode of a tunable laser, in GHz.

[0075] Specifically, the continuously sweeping light generated in step mode, such as Figure 4 The attached diagram (a) shows how the wavelength is adjusted in steps to generate a continuously sweeping light. At each wavelength change, a rising edge trigger pulse is generated, thus generating multiple trigger signals, such as... Figure 4 As shown in the attached figure (b), the continuously sweeping light is split into two parts by the first fiber coupler 220. One part is used as the intrinsic light for subsequent vibration measurement, and the other part is used as the measurement light and enters the electro-optic modulator 230. The waveform generator 240 responds to the trigger signal to form a sequence of sinusoidal pulse electrical signals with increasing frequency. When the step size in the tunable laser's stepping mode is 1 GHz, the sinusoidal pulse electrical signal sequence is as follows: Figure 4 As shown in the attached figure (c), the electro-optic modulator 230 modulates the measurement light based on a sinusoidal pulse electrical signal sequence to generate a tunable pulse light sequence, as shown in Figure (c). Figure 4 As shown in the attached figure (d), a tunable pulsed light sequence enters from one port of the circulator 250 and is transmitted to the heterogeneous grating array 100 via two ports.

[0076] To further improve the signal strength of the tunable pulsed light sequence, in some embodiments of the present invention, such as... Figure 3 As shown, the optical signal generation module 200 also includes an amplifier 260 disposed between the electro-optic modulator 230 and the circulator 250; the amplifier 260 is used to amplify the tunable pulsed light sequence.

[0077] In this embodiment of the invention, by setting amplifier 260 to amplify the tunable pulse light sequence, the signal strength of the tunable pulse light sequence can be further improved, thereby further improving the measurement accuracy of temperature and vibration measurements.

[0078] In some embodiments of the present invention, such as Figure 3 As shown, the signal processing module 300 includes a second fiber optic coupler 310, a photodetector 320, a balanced photodetector 330, and a data acquisition card 340.

[0079] The second fiber optic coupler 310 is used to divide the reflected pulse optical signal into a first reflected pulse photon signal and a second reflected pulse photon signal.

[0080] The photodetector 320 is used to convert the first reflected pulse photon signal into an electrical signal;

[0081] The balanced photodetector 330 is used to perform coherent beat frequency processing on the second reflected pulse photon signal and the intrinsic light to generate a beat frequency signal;

[0082] The data acquisition card 340 is used to obtain temperature measurement results based on multiple trigger signals and electrical signals, and to generate vibration measurement results based on multiple trigger signals and beat frequency signals.

[0083] To avoid mutual interference between electrical signals and beat frequency signals, in a specific embodiment of the present invention, the data acquisition card 340 includes two channels, which respectively receive electrical signals and beat frequency signals, thereby avoiding interference and improving the accuracy of temperature and vibration measurement results.

[0084] In addition to obtaining electrical signals and beat frequency signals, the data acquisition card 340 in this embodiment of the invention also obtains multiple trigger signals. These multiple trigger signals represent the number of wavelength changes. Based on these multiple trigger signals, electrical signals and beat frequency signals of different wavelengths can be spliced ​​together, providing a splicing reference for vibration and temperature measurement results and improving the accuracy of vibration and temperature measurement results.

[0085] Because the wavelengths of the broadband grating 120 and the narrowband grating 130 overlap, in order to accurately separate the first reflected pulse photon signal and the second reflected pulse photon signal, in some embodiments of the present invention, such as... Figure 3 As shown, the signal processing module 300 further includes a signal energy determination unit 350, which is used to determine the optical signal energy of the reflected pulse light signal and to determine the first reflected pulse photon signal and the second reflected pulse photon signal in the reflected pulse light signal based on the optical signal energy and the energy threshold.

[0086] Specifically, reflected pulse light signals with energy less than the energy threshold are classified as first reflected pulse photon signals, and reflected pulse light signals with energy greater than or equal to the energy threshold are classified as second reflected pulse photon signals.

[0087] In a specific embodiment of the present invention, the arrangement of the electrical signal and beat frequency signal acquired by the data acquisition card 340 is as follows: Figure 5 As shown in the figure, the x-axis represents the grating reflection signal at different positions along the fiber optic cable 110. Only the beat frequency signal reflected by the broadband grating 120 is shown in this figure. The y-axis represents the number of trigger signals. The z-axis represents the intensity of the reflected light. Due to the frequency division multiplexing scheme, each time a trigger signal is given to the waveform generator 240, the output from the electro-optic modulator 230 is a sequence containing 5 tunable pulses. Therefore, each time the signal passes through a grating, a sequence of 5 reflected light pulses is generated. The reflected light pulse sequences are arranged at equal intervals along the x-axis and have the same delay, thus preventing crosstalk. Along the y-axis, the fundamental frequency of the tunable light source changes in steps with different trigger pulses, corresponding to multiple wavelengths λ1~λ2 of the continuously sweeping light. n The fundamental frequency of each triggered time pulse is f 1~ fn .

[0088] In specific embodiments of the present invention, such as Figure 3 As shown, the data acquisition card 340 includes a demodulation unit 341 and a splicing unit 342;

[0089] Demodulation unit 341 is used to demodulate electrical signal and beat frequency signal respectively, and obtain multiple first demodulated signals and multiple second demodulated signals accordingly;

[0090] The splicing unit 342 is used to splice multiple first demodulated signals and multiple second demodulated signals based on multiple trigger signals to obtain temperature measurement results and vibration measurement results respectively.

[0091] Specifically, the temperature measurement result determination process is as follows: the light signal intensity reflected back by the narrow band grating 130 is different for tunable pulse light of different wavelengths. Therefore, all the light signals within a complete wavelength scanning range can be collected and spliced ​​together to restore the overall spectrum of the grating.

[0092] Furthermore, for wavelength demodulation during temperature measurement, different wavelengths of tunable pulsed light correspond to a single intensity point. This embodiment of the invention employs a 5x frequency division multiplexing (FDM), thus increasing the intensity point of the overall spectrum of the same grating by a factor of 5. Correspondingly, taking a step size of 1 GHz in the stepping mode of a tunable laser as an example, the wavelength stepping frequency becomes one-fifth of the original, i.e., 200 MHz. After frequency-wavelength conversion, the wavelength resolution becomes one-fifth of the original, therefore the temperature accuracy of temperature demodulation is also improved by a factor of 5.

[0093] Specifically, the vibration measurement result determination process is as follows: Since all the reflected pulse light signals collected by the data acquisition card 340 after frequency division multiplexing in the same pulse triggering do not interfere with each other in the time domain, all pulses of the corresponding frequency can be extracted sequentially for phase demodulation, and finally phase splicing can be performed to obtain the final phase demodulation result.

[0094] And, as Figure 6 As shown, taking a step size of 1GHz in the stepping mode of a tunable laser as an example, after frequency division multiplexing, the time interval between adjacent points in the spliced ​​waveform changes from 1GHz to 200MHz, that is, it becomes one-fifth of the original. Therefore, the maximum detectable frequency response is also increased by 5 times, which improves the vibration measurement accuracy.

[0095] The above provides a detailed description of a heterogeneous grating array and a distributed multi-parameter sensing system provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A distributed multi-parameter sensing system, characterized in that, The light signal generation module is configured to generate a tunable pulsed light sequence and continuous intrinsic light. The light signal generation module is configured to generate a tunable pulsed light sequence and continuous intrinsic light. The heterogeneous grating array is configured to generate a reflected pulsed light signal based on the tunable pulsed light sequence. The signal processing module is configured to perform signal processing on the reflected pulsed light signal and the continuous intrinsic light to obtain vibration measurement results and temperature measurement results. The light signal generation module includes a tunable laser configured to generate continuous swept-frequency light and a plurality of trigger signals in a step mode. The signal processing module includes a second optical fiber coupler, a photodetector, a balanced photodetector, and a data acquisition card. The second optical fiber coupler is configured to divide the reflected pulsed light signal into a first reflected pulsed light sub-signal and a second reflected pulsed light sub-signal. The photodetector is configured to perform signal conversion on the first reflected pulsed light sub-signal to generate an electrical signal. The balanced photodetector is configured to perform coherent beat frequency processing on the second reflected pulsed light sub-signal and the intrinsic light to generate a beat frequency signal. The data acquisition card is configured to obtain the temperature measurement results based on the plurality of trigger signals and the electrical signal, and to generate the vibration measurement results based on the plurality of trigger signals and the beat frequency signal.

2. The distributed multi-parameter sensing system of claim 1, wherein, The light signal generation module further includes a first optical fiber coupler, an electro-optical modulator, a waveform generator, and a circulator. The first optical fiber coupler is configured to divide the continuous swept-frequency light into intrinsic light and measurement light. The waveform generator is configured to generate a sequence of sinusoidal pulsed electrical signals with increasing frequencies in response to the trigger signals. The electro-optical modulator is configured to modulate the measurement light based on the sequence of sinusoidal pulsed electrical signals to generate the tunable pulsed light sequence. The circulator is configured to input the tunable pulsed light sequence to the heterogeneous grating array.

3. The distributed multi-parameter sensing system of claim 2, wherein, The number of signals in the sequence of sinusoidal pulsed electrical signals is: In the formula, N is the number of signals in the sinusoidal pulse electrical signal sequence; is the frequency difference between two adjacent signals in the sinusoidal pulse electrical signal sequence; F is the step size in the step mode of the tunable laser, in GHz.

4. The distributed multi-parameter sensing system of claim 2, wherein, The light signal generation module further includes an amplifier disposed between the electro-optical modulator and the circulator.

5. The distributed multi-parameter sensing system of claim 1, wherein, The amplifier is configured to amplify the tunable pulsed light sequence.

6. The distributed multi-parameter sensing system of claim 1, wherein, The signal processing module further includes a signal energy determination unit configured to determine optical signal energy of the reflected pulsed light signal, and to determine the first reflected pulsed light sub-signal and the second reflected pulsed light sub-signal in the reflected pulsed light signal based on the optical signal energy and an energy threshold. The data acquisition card includes a demodulation unit and a splicing unit. The demodulation unit is configured to demodulate the electrical signal and the beat frequency signal respectively to correspondingly obtain a plurality of first demodulated signals and a plurality of second demodulated signals.

7. The distributed multi-parameter sensing system of claim 1, wherein, The splicing unit is configured to splice the plurality of first demodulated signals and the plurality of second demodulated signals based on the plurality of trigger signals to correspondingly obtain the temperature measurement results and the vibration measurement results.

8. The distributed multi-parameter sensing system of claim 7, wherein, The heterogeneous grating array includes an optical fiber and a broadband grating and a narrowband grating interleavedly inscribed on the optical fiber. The broadband grating and the narrowband grating are inscribed at equal intervals.

9. The distributed multi-parameter sensing system of claim 7, wherein, The 3dB bandwidth of the wideband grating is 1548.71nm~1552.99nm, and the center wavelength of the narrowband grating is 1550.79nm.

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