Brillouin measurement system and method based on scattering enhancement

Abstract

The invention provides a Brillouin measurement system and method based on scattering enhancement, the measurement system outputs probe light and pump light through a laser emission module, the laser emission module preferentially sends the probe light, the probe light is injected into a scattering enhancement optical fiber to generate backscattering enhancement light, and the backscattering enhancement optical fiber generates backscattering enhancement light; the pump light is injected into the scattering enhancement optical fiber in the process of generating the back scattering enhancement light, and the scattering enhancement optical fiber can perform energy transfer on the pump light and the back scattering enhancement light so as to enhance the back scattering enhancement light and obtain Brillouin scattering light with gain information. Analyzing the Brillouin scattering light through an analysis module to obtain gain information; according to the method, the back scattering enhanced light is used as probe light, the temperature information and the strain information of the scattering enhanced optical fiber are determined according to the gain information, the enhanced back scattering enhanced light is used as probe light, the enhanced back scattering enhanced light carries clearer gain information, and the temperature information system and the strain information can be obtained more accurately according to the gain information.

Description

Technical Field

[0001] This application relates to the field of light-sensing Brillouin measurement technology, and in particular to a Brillouin measurement system and method based on scattering enhancement. Background Technology

[0002] Distributed fiber optic sensing technology, especially distributed sensing technology based on the Brillouin scattering effect, has attracted widespread attention in fields such as large-scale infrastructure health monitoring, geological disaster early warning, and oil and gas pipeline safety monitoring because it can measure physical quantities such as temperature and strain along the entire fiber. Current distributed Brillouin sensing technology measures the temperature and strain of optical fibers based on Brillouin light reflection; however, its measurement efficiency is limited by the weakness of the backscattered signal when applying high-precision, long-distance, and high-reliability applications. Summary of the Invention

[0003] In view of this, the purpose of this application is to propose a Brillouin measurement system and method based on scattering enhancement, so as to solve some or all of the technical problems existing in the background art.

[0004] To achieve the above objectives, this application provides a Brillouin measurement system based on scattering enhancement, comprising:

[0005] A laser emitting module is used to output probe light and pump light, wherein the probe light is continuous light and the pump light is intermittent light; A backscattering enhancement fiber is used to receive the probe light and the pump light, so that the backscattering enhancement light generated by the probe light meets the pump light to generate Brillouin scattered light with gain information. An analysis module is used to receive the Brillouin scattered light, analyze the Brillouin scattered light to obtain gain information, and determine the temperature and strain information of the scattering-enhancing fiber based on the gain information.

[0006] Optionally, the scattering enhancement fiber is a fiber Bragg grating fiber, which includes a periodically distributed array of identical weak gratings. The reflectivity range for each weak grating is set to 0.00006%-0.01%.

[0007] Optionally, the laser emitting module includes a narrow-line laser and a polarization-maintaining coupler, wherein the polarization-maintaining coupler splits the incident light from the narrow-line laser into a probe light branch and a pump light branch; The probe light branch includes: a first electro-optic modulator, a microwave signal generator, a first fiber amplifier, and a first optical filter; the microwave signal generator is used to generate an electrical signal to drive the first electro-optic modulator to output two sideband lights; the first fiber amplifier is used to amplify the two sideband lights and inject them into the first optical filter; the first optical filter is used to select one sideband light as the probe light and inject it into the scattering enhancement fiber. The pump light branch includes: a second electro-optic modulator, an arbitrary waveform generator, a second fiber amplifier, and a second optical filter; the arbitrary waveform generator is used to generate an electrical pulse sequence to drive the second electro-optic modulator to output an optical pulse sequence; the second fiber amplifier is used to amplify the optical pulse sequence and inject it into the second optical filter; the second optical filter is used to filter out the spontaneous emission noise of the optical pulse sequence to form pump light and inject it into the scattering enhancement fiber; The microwave signal generator generates an electrical signal to drive the first electro-optic modulator to output sideband light as continuous light, and the arbitrary waveform generator drives the second electro-optic modulator to output a sequence of light pulses as discontinuous light.

[0008] Optionally, the system further includes a signal processing module, which processes the probe light emitted from the probe light branch and the pump light emitted from the pump light branch and injects them into the scattering enhancement fiber, while simultaneously receiving the Brillouin scattered light reflected from the scattering enhancement fiber and injecting it into the analysis module.

[0009] Optionally, the signal processing module includes: a polarization disruptor, an optical coupler, and a main optical path circulator; The polarization disruptor is used to polarize the probe light and the pump light to achieve polarization equalization and inject them into the optical coupler; The optical coupler is used to couple the probe light and the pump light and inject them into the main optical path circulator; The main optical path circulator is used to inject the probe light and the pump light into the scattering enhancement fiber and to receive the Brillouin scattered light reflected by the scattering enhancement fiber and inject it into the analysis module.

[0010] Optionally, the analysis module includes a third optical filter, a photodetector, a data acquisition card, and a controller connected in sequence; The third optical filter is used to filter out interference light from the Brillouin scattering light and inject it into the photodetector; The photodetector is used to convert the Brillouin scattered light into an electrical signal and inject it into the data acquisition card; The data acquisition card is used to convert the electrical signal into a digital signal for recording; The controller is used to plot and analyze the Brillouin spectrum of the recorded digital signal to obtain gain information; and to determine the temperature and strain information of the scattering enhancement fiber based on the gain information.

[0011] Based on the same inventive concept, this application provides a Brillouin measurement method based on scattering enhancement, applicable to any of the above-described scattering enhancement-based Brillouin measurement systems, comprising: The laser emission module outputs a probe light and a pump light, the output times of which are different. The probe light and the pump light are received by a scattering enhancement fiber, so that the backscattering enhancement light generated by the probe light meets the pump light to generate Brillouin scattered light with gain information. The Brillouin scattered light is received by the analysis module, and the Brillouin scattered light is analyzed to obtain gain information; based on the gain information, the temperature information and strain information of the scattering enhancement fiber are determined.

[0012] Optionally, the probe light and the pump light are received through a scattering-enhancing fiber, so that the backscattering-enhancing light generated by the probe light meets the pump light to generate Brillouin scattered light with gain information, including: The probe light is injected into the scattering-enhancing fiber to obtain a backscattering-enhanced optical signal and a backscattering Rayleigh component optical signal. The backscattering enhanced optical signal and the backscattering Rayleigh component optical signal are added together to obtain the backscattering enhanced signal; The pump light is injected into the scattering-enhancing fiber to allow the pump light to undergo phonon energy transfer with the backscattering-enhancing signal, thereby generating the Brillouin scattered light.

[0013] Optionally, the gain information includes the Brillouin gain spectrum; Analysis of the Brillouin scattered light with gain information yields the gain information, including: The Brillouin scattered light is photoelectrically converted to obtain a time-domain electrical signal; The position of the Brillouin scattered light is determined based on the time-domain electrical signal. The Brillouin gain spectrum is determined based on the position of the Brillouin scattered light and the preset frequency difference corresponding to that position.

[0014] Optionally, the gain information includes the Brillouin gain spectrum; Based on the gain information, the temperature and strain information of the scattering-enhancing fiber are determined, including: Based on the Brillouin gain spectrum, a linear equation is determined; based on the preset calibration information and the linear equation, the temperature information and the strain information are obtained.

[0015] As can be seen from the above, the Brillouin measurement system and method based on scattering enhancement provided in this application, wherein the measurement system outputs probe light and pump light through a laser emitting module, wherein the probe light is continuous light and the pump light is discontinuous light. It can be understood that the laser emitting module A injects the continuous light of the probe light into the scattering enhancement fiber SE-SMF, and at the same time injects the discontinuous light of the pump light into the scattering enhancement fiber. Since the continuous light is continuously injected and the discontinuous light is injected intermittently, the probe light generates backscattering enhancement light in the scattering enhancement fiber SE-SMF. During the generation of backscattering enhancement light, the discontinuous light of the pump light is re-injected, so that the pump light and the backscattering enhancement light meet. When the pump light and the backscattering enhancement light satisfy the frequency shift condition (the frequency shift condition is: the difference between the frequency of the pump light and the frequency of the probe light), the energy of the pump light is transferred to the backscattering enhancement light to enhance the backscattering enhancement light, so that the enhanced scattered light obtains Brillouin gain (or loss) at the corresponding spatial position of the scattering enhancement fiber, thereby obtaining Brillouin scattered light with gain information. Since Brillouin scattered light carries gain information, the gain information is obtained by analyzing the Brillouin scattered light using an analysis module. Then, the temperature and strain information of the scattering-enhanced fiber are determined based on the gain information. In this application, the enhanced backscattered signal is used as the probe light, and Brillouin gain modulation is obtained under stimulated Brillouin scattering, thereby enhancing the Brillouin measurement signal. The enhanced Brillouin scattered signal carries clearer gain information, and the temperature and strain information can be obtained more accurately based on this gain information. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a Brillouin measurement system framework based on scattering enhancement, according to an embodiment of this application. Figure 2 This is a schematic diagram of the scattering-enhancing fiber structure according to an embodiment of this application; Figure 3 This is a schematic diagram of the reflection of the probe light and pump light within the scattering-enhancing fiber according to an embodiment of this application; Figure 4 This is a schematic flowchart of a Brillouin measurement method based on scattering enhancement according to an embodiment of this application; Figure 5a This is a simulation diagram of the intensity of the scattered signal of the scattering-enhancing fiber according to an embodiment of this application; Figure 5b This is a simulation diagram illustrating the inherent Rayleigh scattering intensity of a common single-mode optical fiber according to an embodiment of this application. Figure 6 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of this application.

[0018] Figure label: A. Laser emission module; A1. Probe light branch; A2. Pump light branch; B. Signal processing module; C. Analysis module; Laser: Narrow linewidth laser; PMC: Polarization-maintaining coupler; EOM1: First electro-optic modulator; MSS: Microwave signal generator; EDFA1: Fiber amplifier-1; OF1: First optical filter; EOM2: Second electro-optic modulator; AWG: Arbitrary waveform generator; EDFA2: Second fiber amplifier; OF2: Second optical filter; PS: Polarization disruptor; OC: Optical coupler; OCR: Main optical path circulator; OF3: Third optical filter; PD: Photodetector; DAQ: Data acquisition card; Computer: Computer; SE-SMF: Scattering enhancement fiber. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0020] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0021] As described in the background, current distributed Brillouin sensing technologies mainly include Brillouin Optical Time Domain Analysis (BOTDA) systems based on Stimulated Brillouin Scattering (SBS) and Brillouin Optical Time Domain Reflectometry (BOTDR) systems based on Spontaneous Brillouin Scattering (SpBS). However, regardless of the sensing system used, existing Brillouin scattering sensing systems generally face a common fundamental technical bottleneck when facing high-precision, long-distance, and high-reliability applications: the system's signal-to-noise ratio (SNR) is limited by the weakness of the backscattered signal. Brillouin scattering is a weak scattering effect, and the backscattered enhanced optical power generated along the optical fiber is low. This often leads to the system relying on a large number of averaging, high-gain amplifications or more complex optoelectronic detection links to ensure measurement accuracy and stability, thus limiting measurement efficiency and engineering applicability. While traditional two-end BOTDA systems can achieve a high signal-to-noise ratio through the interaction of high-power pump and probe light, they typically require equipment to be deployed at both ends of the fiber or the far end of the fiber to be looped back to the starting end. This is difficult to meet deployment requirements in application scenarios where only single-end access is permitted or where far-end deployment is not feasible. Therefore, there is an urgent need for a method and system to enhance Brillouin scattering signal strength and improve the signal-to-noise ratio.

[0022] Existing research has also proposed using scattering-enhanced fibers to strengthen the intensity of backscattered signals. These fibers are generally classified into two categories: continuous scattering-enhanced fibers and discrete scattering-enhanced fibers. Continuous scattering enhancement improves the scattering level by doping modification or writing continuous structures, achieving overall enhancement of Rayleigh scattering at the fiber material or structural level. However, it introduces additional optical losses, increasing link attenuation and shortening the effective detection distance.

[0023] Discrete scattering enhanced fiber achieves discrete enhancement by introducing periodically distributed weak reflection / weak scattering units into the fiber. This transforms the uncontrollable and highly random Rayleigh scattering distribution in traditional optical fibers into a stable, controllable discrete reflection array with high signal-to-noise ratio characteristics, thereby enhancing the backscattered signal while improving the system's signal-to-noise ratio.

[0024] Based on this, if the enhanced backscattered signal is further introduced into the Brillouin measurement link and used as a probe light to interact with the pump light, an effective conversion from backscattering enhancement to Brillouin enhancement can be achieved, realizing a Brillouin-enhanced distributed measurement system.

[0025] To solve the above technical problems, such as Figure 1 As shown, this application provides a Brillouin measurement system based on scattering enhancement, comprising: Laser emitting module A is used to output probe light and pump light, wherein the probe light is continuous light and the pump light is intermittent light; The backscattering enhancement fiber SE-SMF is used to receive the probe light and the pump light, so that the backscattering enhancement light generated by the probe light meets the pump light to generate Brillouin scattered light with gain information. Analysis module C is used to receive the Brillouin scattered light and analyze the Brillouin scattered light to obtain gain information; based on the gain information, the temperature information and strain information of the scattering enhancement fiber SE-SMF are determined.

[0026] Specifically, laser emitting module A outputs probe light and pump light, where the probe light is continuous and the pump light is discontinuous. This can be understood as laser emitting module A injecting the continuous probe light into the SE-SMF (Self-Scattering Enhancement Fiber), while simultaneously injecting the discontinuous pump light into the SE-SMF. Because the continuous light is injected continuously while the discontinuous light is injected intermittently, the probe light generates backscattering enhancement light in the SE-SMF. During the generation of backscattering enhancement light, the discontinuous pump light is re-injected, causing the pump light and backscattering enhancement light to meet. When the pump light and backscattering enhancement light satisfy the frequency shift condition (the frequency shift condition is the difference between the frequency of the pump light and the frequency of the probe light), the energy of the pump light is transferred to the backscattering enhancement light, thereby enhancing the backscattering enhancement light. This enhances the backscattering light, allowing it to gain Brillouin gain (or loss) at the corresponding spatial position in the SE-SMF, thus obtaining Brillouin scattered light with gain information. Since Brillouin scattered light carries gain information, the gain information is obtained by analyzing the Brillouin scattered light through analysis module C. Then, the temperature and strain information of the scattering-enhanced fiber are determined based on the gain information. In this application, the enhanced backscattered signal is used as the probe light, and Brillouin gain modulation is obtained under stimulated Brillouin scattering, thereby enhancing the Brillouin measurement signal. The enhanced Brillouin scattered signal carries clearer gain information, and the temperature and strain information can be obtained more accurately based on the gain information. Due to the improvement in signal strength and signal-to-noise ratio, the system is more sensitive to changes in temperature and strain, and the linear relationship between Brillouin frequency shift and temperature and strain is more accurately fitted, reducing measurement errors. This makes the accuracy and stability of distributed temperature and strain measurements significantly better than traditional systems, meeting the needs of high-precision monitoring (such as large-scale infrastructure health monitoring, geological disaster early warning, etc.).

[0027] In some embodiments, such as Figure 2 As shown, the scattering-enhancing fiber SE-SMF uses fiber Bragg grating fiber, which includes a periodically distributed array of identical weak gratings.

[0028] For example, such as Figure 2 and Figure 3 As shown, the scattering-enhancing fiber SE-SMF uses a weak fiber Bragg grating (WFBG) fiber. This WFBG fiber is formed by using a femtosecond laser to etch a periodically distributed array of identical weak gratings into the core of a single-mode fiber. Each weak grating unit serves as a discrete scattering-enhancing point (SEP), and its structural parameters, such as grating length and spacing between adjacent gratings, can be flexibly designed and adjusted according to system resolution, range, and signal-to-noise ratio requirements (e.g., the grating spacing can be set to 5m). The reflectivity of each weak grating is strictly controlled at a low level, preferably within the range of 0.00006%-0.01% (typically below 0.01%). This ensures effective enhancement of the backscattered signal while avoiding additional optical loss in the link due to excessively high reflectivity, ensuring controllable link loss during long-distance transmission. This identical weak grating array transforms the sensing link from the uncontrollable and highly random Rayleigh scattering distribution in traditional optical fibers into a stable, controllable discrete reflection array with high signal-to-noise ratio characteristics. When the probe light is incident, the back reflection components generated by each weak grating unit are superimposed and converged along the near end of the optical fiber, combining with the inherent backscattering Rayleigh component of the optical fiber to form a backscattering enhancement signal. This provides a high-intensity probe light substrate for subsequent stimulated Brillouin scattering (SBS) interactions, thereby achieving Brillouin signal enhancement and system signal-to-noise ratio improvement.

[0029] In some embodiments, the reflectivity of each weak grating is set to the range of 0.00006%-0.01%.

[0030] Specifically, the reflectivity range of each weak grating was set to 0.00006%-0.01%. To enhance the backscattered signal while controlling link loss and ensuring long-distance transmission, the lower limit of reflectivity was set to 0.01% to provide controllable discrete reflection while ensuring long-distance transmission. This balances the key upper limits of "signal enhancement" and "low loss," preventing excessively high reflectivity from increasing link attenuation. Experiments have shown that a reflectivity range of 0.00006%-0.01% provides sufficient backscatter enhancement while meeting the requirements of low loss and high reusability, making it the optimal range for balancing "performance," "cost," and "applicability," whether for long-distance monitoring using distributed Brillouin measurements (such as oil and gas pipelines and geological early warning) or for acoustic detection and tunnel rock monitoring.

[0031] In some embodiments, such as Figure 1 As shown, the laser emitting module A includes a narrow-line laser and a polarization-maintaining coupler (PMC). The PMC splits the incident light from the narrow-line laser into a probe light branch A1 and a pump light branch A2. The probe light branch A1 includes: a first electro-optic modulator EOM1, a microwave signal generator MSS, a first fiber amplifier, and a first optical filter OF1; the microwave signal generator MSS is used to generate an electrical signal to drive the first electro-optic modulator EOM1 to output two sideband lights; the first fiber amplifier is used to amplify the two sideband lights and inject them into the first optical filter OF1; the first optical filter OF1 is used to select one sideband light as the probe light and inject it into the scattering enhancement fiber SE-SMF; The pump light branch A2 includes: a second electro-optic modulator EOM2, an arbitrary waveform generator AWG, a second fiber amplifier EDFA2, and a second optical filter OF2; the arbitrary waveform generator AWG is used to generate an electrical pulse sequence to drive the second electro-optic modulator to output an optical pulse sequence; the second fiber amplifier EDFA2 is used to amplify the optical pulse sequence and inject it into the second optical filter OF2; the second optical filter OF2 is used to filter out the spontaneous emission noise of the optical pulse sequence to form pump light and inject it into the scattering enhancement fiber SE-SMF; The microwave signal generator (MSS) generates an electrical signal to drive the first electro-optic modulator (EOM1) to output continuous sideband light, while the arbitrary waveform generator (AWG) drives the second electro-optic modulator (EOM2) to output intermittent light pulse sequences. The continuous light, being sideband light, enables continuous injection of light into the backscattering enhancement fiber. The intermittent light, being a pulse signal, enables intermittent injection of light into the backscattering enhancement fiber. This misaligns the injection timing of the probe light with that of the pump light, allowing the pump light and probe light to meet in the backscattering enhancement light generated within the fiber, producing Brillouin scattered light with gain information.

[0032] Specifically, the laser emitting module A uses a narrow-linewidth laser as the core sensing light source. The continuous laser with a stable center frequency and extremely narrow linewidth output is precisely split into two paths by a polarization-maintaining coupler (PMC) according to a preset splitting ratio (e.g., 50:50)—a probe light branch A1 and a pump light branch A2. The use of the polarization-maintaining coupler (PMC) can effectively maintain the polarization stability of the two optical signals and avoid polarization drift from interfering with the interaction of subsequent optical signals and measurement accuracy. The structure and operation of the probe light branch A1 are as follows: The first electro-optic modulator EOM1 in the branch is driven by a high-frequency sinusoidal electrical signal provided by a microwave signal generator MSS. Through carrier-suppressed double-sideband modulation technology, the incident continuous laser is decomposed into two sideband lights with symmetrical frequency distribution (frequency f0+fm and f0-fm, respectively, where f0 is the center frequency of the narrow-linewidth laser and fm is the frequency of the electrical signal output by the microwave signal generator MSS). Subsequently, these two sideband lights enter the first fiber amplifier EDFA1 for power amplification to ensure that the optical signal has sufficient intensity to support long-distance transmission and backscattering enhancement. The amplified sideband lights are then injected into the first optical filter OF1. Through filtering, only one sideband light (such as f0-fm) is retained as the final continuous probe light, while the other sideband light and stray light generated during modulation are filtered out to ensure the frequency purity and signal stability of the probe light. The pump light branch A2 is structured and operates as follows: another continuous laser beam is incident on the second electro-optic modulator EOM2, which is driven by an electrical pulse sequence with a specific pulse width (e.g., 50 ns) and repetition frequency generated by an arbitrary waveform generator (AWG). This modulator modulates the continuous laser beam into a light pulse sequence that meets the excitation requirements of Brillouin scattering, while maintaining its center frequency at f0. The light pulse sequence then enters the second fiber amplifier EDFA2, where it is amplified to a high power level sufficient to excite the Brillouin effect. The amplified light pulse sequence is then filtered by the second optical filter OF2, primarily filtering out the spontaneous emission noise generated during the operation of the fiber amplifier. This ultimately forms a high-power, low-noise pump light pulse injected into the scattering-enhanced fiber SE-SMF. Crucially, the continuous light is a sideband light, enabling continuous injection into the scattering-enhanced fiber. The intermittent light is a pulse signal, enabling intermittent injection into the scattering-enhanced fiber. This ensures that the injection time of the probe light and the pump light are misaligned, guaranteeing that they accurately meet the frequency difference condition for stimulated Brillouin scattering (SBS). This lays the foundation for the meeting of two beams and signal enhancement. Thus, it is possible to achieve the meeting of the pump light and the probe light generated within the scattering enhancement fiber, producing Brillouin scattered light with gain information.

[0033] In some embodiments, the system can also, through precise timing control, ensure that the moment when the microwave signal generator (MSS) generates an electrical signal to drive the first electro-optic modulator (EOM1) to output sideband light, and the moment when the arbitrary waveform generator (AWG) drives the second electro-optic modulator (EOM2) to output a sequence of optical pulses, have a preset time difference. This time difference must be designed to match the propagation speed of the probe light in the scattering-enhanced fiber (SE-SMF), the return time of the backscattering enhancement signal, and the requirement that the pump pulse and the backscattering enhancement signal meet at a certain position z in the enhanced fiber, ensuring that both accurately meet the frequency difference condition for stimulated Brillouin scattering (SBS). This lays the foundation for the encounter of two lights and signal enhancement.

[0034] Based on the above description, the technical effects achievable in this embodiment are as follows: Ensuring the purity and stability of the optical signal and solidifying the measurement foundation: A stable center frequency light source is provided by a narrow-linewidth laser (Laser), coupled with two-stage optical filtering (first optical filter OF1, second optical filter OF2), respectively eliminating stray sideband light from the probe light branch A1 and spontaneous emission noise from the pump light branch A2. This ensures that both the probe and pump lights possess high frequency purity and low noise characteristics, avoiding interference from stray light on Brillouin scattering interactions, and providing a high-quality optical signal foundation for subsequent signal detection and analysis. Achieving on-demand modulation of the optical signal to adapt to the requirements of SBS: The probe light branch A1 obtains a continuous probe light with precisely controllable frequency through double-sideband modulation and single-path selection, which can flexibly match the Brillouin frequency shift characteristics of the scattering enhancement fiber SE-SMF; the pump light branch A2 generates high-power pump light pulses, i.e., intermittent light, through pulse modulation and power amplification, meeting the energy threshold requirements of stimulated Brillouin scattering. By injecting continuous and intermittent light into the backscattering enhancement fiber, the time difference between the continuous and intermittent light ensures that the pump light pulse and the backscattering enhancement signal meet precisely at a certain position in the fiber and undergo stimulated Brillouin scattering. This avoids the decrease in energy transfer efficiency caused by timing misalignment, maximizes the energy transfer efficiency from the pump light to the probe light, and thus significantly enhances the distinguishability of the intensity and gain changes of the Brillouin scattering signal. Optimized system integration and reliability: Laser emission module A adopts an integrated design of "single light source + dual branches," eliminating the need for multiple additional light sources, simplifying the system structure, and reducing equipment complexity and cost. Simultaneously, the clear functional division of each component, along with design details such as polarization-maintaining design, filtering and noise reduction, and coordinated light injection timing, collectively improves the long-term operational stability of the system, making it suitable for engineering applications involving long-distance, high-precision distributed measurements.

[0035] In some embodiments, such as Figure 1As shown, the system further includes a signal processing module B, which processes the probe light emitted from the probe light branch A1 and the pump light emitted from the pump light branch A2 and injects them into the scattering enhancement fiber SE-SMF, while simultaneously receiving the Brillouin scattered light reflected by the scattering enhancement fiber SE-SMF and injecting it into the analysis module C.

[0036] Specifically, signal processing module B is a functionally integrated signal processing module. As the core signal transmission and adaptation hub between laser emission module A, scattering-enhancing fiber SE-SMF, and analysis module C, this module not only undertakes the function of preprocessing the continuous probe light output from probe light branch A1 and the pump light pulse output from pump light branch A2, and accurately injecting them into scattering-enhancing fiber SE-SMF after converging, but also is responsible for efficiently receiving the Brillouin scattering light carrying temperature / strain information reflected back from scattering-enhancing fiber SE-SMF and directionally transmitting it to analysis module C, realizing closed-loop transmission control of optical signal "injection-feedback", and ensuring the signal transmission efficiency and stability of the entire measurement link.

[0037] In this embodiment, as Figure 1 As shown, the signal processing module B includes: a polarization disruptor PS, an optical coupler OC, and a main optical path circulator OCR; The polarization disruptor PS is used to polarize the probe light and the pump light to achieve polarization equalization and inject them into the optical coupler OC. The optical coupler OC is used to couple the probe light and the pump light and inject them into the main optical path circulator OCR; The main optical path circulator (OCR) is used to inject the probe light and the pump light into the scattering enhancement fiber (SE-SMF) and to receive the Brillouin scattered light reflected by the SE-SMF and inject it into the analysis module C.

[0038] Specifically, the signal processing module B consists of a polarization scrambler (PS), an optical coupler (OC), and a main optical path circulator (OCR) connected in series according to their functional logic. These components work together to optimize the optical signal in all aspects. The polarization scrambler (PS), acting as a preprocessing unit, receives continuous probe light from probe branch A1 and pump light pulses from pump branch A2. By dynamically adjusting the polarization states of the two optical signals, it breaks the polarization dependence caused by polarization drift during signal transmission, achieving polarization equalization. Its core function is to eliminate the impact of polarization instability on the efficiency of stimulated Brillouin scattering (SBS) interaction—since Brillouin scattering gain is sensitive to the polarization state of the optical signal, polarization equalization ensures that the pump light and the backscattering enhancement signal maintain stable coupling efficiency at all points in the optical fiber, avoiding signal strength fluctuations or gain attenuation due to polarization mismatch. The optical coupler (OC) receives the two optical signals output from the polarization scrambler (PS) and efficiently merges the continuous probe light and pump light pulses into a single composite optical signal according to a preset coupling ratio (matching the power requirements and transmission characteristics of the probe and pump lights). The design of this component must balance signal transmission loss and convergence accuracy, minimizing optical power loss while ensuring complete coupling and no mutual interference between the two optical signals. This provides a structural foundation for subsequent single-port injection of the scattering-enhanced fiber SE-SMF, simplifying the complexity of optical path connections. The main optical path circulator OCR, as the core component for directional signal transmission, employs a multi-port (e.g., three-port) directional transmission design: its first port receives the composite optical signal output from the optical coupler OC, which is then guided through an internal optical path to the second port, precisely injecting the probe and pump light pulses into the scattering-enhanced fiber SE-SMF. When the backscattering enhancement signal in the SE-SMF interacts with the pump light via SBS, the resulting Brillouin scattered light is transmitted back along the fiber to the second port of the circulator. The circulator then guides this reflected signal to the third port through a directional transmission mechanism, achieving physical isolation between the "injected light" and the "reflected light." This prevents the reflected signal from flowing back to the laser emission module A or the optical coupler OC, causing signal interference. Finally, the Brillouin scattered light is directionally injected into the analysis module C, ensuring the unidirectionality and purity of signal transmission.

[0039] The technical effects of this embodiment are as follows: Improved stability of SBS operation and guaranteed signal enhancement: Through polarization equalization processing by the polarization disruptor PS, the adverse effects of polarization state drift on Brillouin scattering gain are effectively avoided. This ensures stable encounter efficiency between the pump light and the backscattering enhancement signal throughout the entire fiber link, guaranteeing the consistency and repeatability of the Brillouin scattering signal intensity and avoiding measurement errors caused by polarization mismatch. Optimized optical path structure and reduced system complexity: The optical coupler OC achieves efficient convergence of the two optical signals. Combined with the single-port injection / feedback design of the main optical path circulator OCR, the probe light and pump light can be connected to the scattering enhancement fiber SE-SMF through the same port. This eliminates the need for separate incident and receiving devices at both ends of the fiber, further enhancing the advantages of single-end measurement. Simultaneously, it simplifies the optical path connection and deployment process, reducing installation and maintenance costs in engineering applications. Achieving directional signal isolation and improving signal purity: The directional transmission function of the main optical path circulator OCR successfully isolates the injected and reflected light, preventing Brillouin scattered light from flowing back to the laser emission module A and causing light source interference. It also avoids the generation of stray light by superimposing with the incident light, ensuring that the Brillouin scattered light transmitted to the analysis module C has high purity and low interference characteristics. This provides a clear signal source for subsequent photoelectric conversion and spectrum analysis, indirectly improving the system's signal-to-noise ratio and measurement accuracy. Enhancing system adaptability and reliability: The modular design of the signal processing module B allows each component to flexibly adjust parameters (such as polarization disturbance frequency, coupling ratio, circulator port loss) according to actual application scenarios (such as transmission distance, fiber type, and environmental conditions) to adapt to different measurement needs. At the same time, the collaborative work between components reduces loss and interference during optical signal transmission, improving the system's reliability in long-distance and complex environments, and meeting the application requirements of demanding scenarios such as large-scale infrastructure monitoring and geological disaster early warning.

[0040] In some embodiments, such as Figure 1 As shown, the analysis module C includes a third optical filter OF3, a photodetector PD, a data acquisition card DAQ, and a controller connected in sequence. The third optical filter OF3 is used to filter out the interference light from the Brillouin scattering light and inject it into the photodetector PD. The photodetector is used to convert the Brillouin scattered light into an electrical signal and inject it into the data acquisition card DAQ. The data acquisition card DAQ is used to convert the electrical signal into a digital signal for recording. The controller is used to plot and analyze the Brillouin spectrum of the recorded digital signal to obtain gain information; and to determine the temperature and strain information of the scattering enhancement fiber based on the gain information.

[0041] Specifically, the analysis module C, as the core of the entire measurement system's signal analysis, adopts a full-link processing architecture of "filtering-conversion-acquisition-analysis." It consists of a third optical filter OF3 (OF-3), a photodetector PD (PD), a data acquisition card DAQ (DAQ), and a controller (such as a computer) connected precisely in sequence according to the signal transmission flow, forming a closed-loop analysis link from optical signal to physical quantity data. This module receives the Brillouin scattered light transmitted from the signal processing module B and, through hierarchical signal optimization and data processing, ultimately transforms the optical signal carrying temperature / strain information into intuitive and accurate measurement results, providing core data support for distributed monitoring. The third optical filter OF3 acts as the first "purification checkpoint" for the signal entering the analysis module C, specifically filtering out interfering light components mixed in with the Brillouin scattered light—including residual pump light that did not participate in stimulated Brillouin scattering (SBS), inherent Rayleigh scattering stray light from the fiber, and environmental stray light introduced during transmission. Its filtering bandwidth and center frequency are strictly matched to the signal characteristics of Brillouin scattered light, maximizing the preservation of effective Brillouin scattered light energy while significantly reducing the impact of interference light on subsequent detection, providing a high-purity optical signal source for subsequent signal conversion. The photodetector PD uses a photosensitive element with high responsivity and low dark current. After receiving the pure Brillouin scattered light output from the third optical filter OF3, it converts the optical signal (change in optical power) into a corresponding analog electrical signal (change in current or voltage) based on the photoelectric effect. The response speed and detection bandwidth of this component must be adapted to the time-domain characteristics of Brillouin scattered light to ensure accurate capture of the amplitude and phase change details of the optical signal—these details are directly related to the SBS gain information at various locations in the optical fiber and are the core foundation for subsequent data analysis. Its low dark current design can further reduce the interference of its own noise on the signal. The data acquisition card (DAQ) acts as a hub for converting analog to digital signals. Through a preset sampling rate (matching the signal frequency of the Brillouin scattering light) and sampling precision (e.g., 16 bits or higher), it performs high-speed, high-precision acquisition and quantization of the analog electrical signal output from the photodetector (PD). This converts the continuously changing analog signal into a discrete digital signal and records and buffers the data in a time sequence. This component must possess low sampling noise and high timing consistency to ensure that the digital signal accurately reproduces the gain variation characteristics of the analog electrical signal, avoiding measurement errors caused by sampling distortion.The controller (usually a computer equipped with dedicated data processing software) acts as the "brain" of the module, undertaking the core data analysis task: First, it calls a preset algorithm to preprocess the digital signals recorded by the data acquisition card DAQ (such as noise reduction and signal alignment). Then, based on the time resolution principle, it accurately correlates the signals acquired at different times with the corresponding spatial locations on the optical fiber. Subsequently, it plots the Brillouin gain spectrum (BGS) for each spatial location by fitting the frequency difference scanning data, and obtains the Brillouin frequency shift spectrum (BFS) from the BGS using a peak extraction algorithm, completing the core analysis of the gain information. Finally, it combines preset calibration coefficients (temperature coefficient and strain coefficient of the Brillouin frequency shift) and uses a linear equation solving method to convert the Brillouin frequency shift value into corresponding temperature and strain information. At the same time, it can generate a distributed temperature / strain distribution map along the optical fiber, intuitively presenting the measurement results.

[0042] The technical effects of this embodiment are as follows: Improved signal purity and reduced measurement errors: The precise filtering design of the third optical filter (OF3) effectively eliminates interference light, and the low-noise characteristics of the photodetector (PD) reduce noise introduction during signal conversion. Together, they improve the signal-to-noise ratio of the effective signal. The high sampling accuracy of the data acquisition card (DAQ) and the precise algorithm of the controller ensure distortion-free signal conversion and analysis from light to electricity and from analog to digital, significantly reducing system errors at each stage and guaranteeing high accuracy for temperature / strain measurements. Accurate correlation and efficient analysis of distributed data: The controller's spatial location matching function based on time-resolved technology can accurately locate the signal source of each measurement point on the optical fiber, achieving distributed data acquisition along the entire length of the fiber. Combined with automated spectrum plotting, peak extraction, and physical quantity conversion algorithms, rapid analysis of massive amounts of data can be completed without manual intervention, significantly improving measurement efficiency and avoiding the tediousness and errors of traditional manual analysis. Ensuring the reliability and intuitiveness of measurement results: Standardized processing across the entire chain, from optical signal purification to data analysis, ensures the repeatability and stability of measurement results, adapting to long-term, continuous monitoring scenarios. The distributed temperature / strain spectrum output by the controller transforms abstract gain information into intuitive physical quantity data, facilitating quick understanding of environmental changes or structural stress states along the fiber optic cable and lowering the barrier to data interpretation. Enhancing system flexibility and adaptability: The parameters of each component (such as the filtering bandwidth of the third optical filter OF3, the sampling rate of the data acquisition card DAQ, and the analytical algorithm parameters of the controller) can be flexibly adjusted according to actual measurement needs (such as fiber length, measurement accuracy requirements, and monitoring environment). This adapts to both short-distance, high-precision measurement scenarios and long-distance distributed monitoring needs, expanding the system's application scope.

[0043] The specific measurement process of the Brillouin measurement system in this application includes: a narrow-line laser (Laser) as the sensing light source generates a beam with a center frequency of... The continuous laser light is split into two paths by a 50:50 polarization-maintaining coupler (2). The first path (probe light branch A1): After the optical signal passes through the first electro-optic modulator EOM1, the microwave signal generator MSS generates a high-frequency sinusoidal electrical signal with a frequency of fm to drive the first electro-optic modulator EOM1. The first electro-optic modulator EOM1 performs carrier-suppressed double-sideband modulation and outputs two sideband lights with frequencies of f0+fm and f0-fm respectively. After the two sideband lights enter the first optical filter OF1, only one sideband is retained. Finally, a single-sideband continuous preliminary probe light is output from this branch. The second path (pump light branch A2): After continuous light enters the second optical filter EOM2, the arbitrary waveform generator (AWG) generates an electrical pulse sequence with a specific pulse width and repetition frequency to drive the second optical filter EOM2. The second optical filter EOM2 modulates the continuous light into an optical pulse sequence with a center frequency of f0. The optical pulse then enters the second fiber amplifier (EDFA), and its peak power is amplified to a level sufficient to excite the Brillouin effect. After passing through the second optical filter OF2, the spontaneous emission noise generated by the second fiber amplifier EDFA2 is filtered out. Finally, a high-power, low-noise pump light pulse with a frequency of fPump=f0 is output from this branch.

[0044] The continuous probe light from the probe branch and the pump pulse from the pump branch are coupled through the polarization disruptor (PS) and then injected into the optical coupler (OC). The injected light is then output from port 2 of the main optical path circulator (OCR), achieving injection into the backscattering enhancement fiber (SE-SMF) from the same port. After injection, the initial probe light propagates forward. When it encounters a WFBG array matching its wavelength, it is reflected, forming a backscattering continuous beam. This reflected light superimposes with the inherent Rayleigh backscattering of the fiber, forming a backscattering enhancement signal. Simultaneously, the pump pulse also propagates forward along the fiber. At a certain position z in the fiber, the pump pulse will encounter the backscattering enhancement signal. At this point, if the frequency difference between the two beams is fPumb - fProbe = f0 - (f0 - fm) = fm, and fm is exactly equal to the Brillouin frequency shift of the fiber at that position... This results in strong stimulated Brillouin scattering. The energy of the pump light is transferred to the backscattering enhancement signal, causing changes in both its amplitude and phase. These changes are related to the temperature / strain at position z, thus carrying distributed temperature / strain information. The backscattering signal carrying the stimulated Brillouin scattering information is transmitted back through port 2 of the main optical path circulator OCR and output through port 3. It then passes through the third optical filter OF3 and enters the photodetector PD for detection. Data is then acquired by the data acquisition card DAQ, and spectral reconstruction and peak extraction are performed in the data processing unit of the computer to obtain the BGS (Brillouin gain spectrum) and the corresponding BFS (Brillouin frequency shift spectrum) values ​​at each position along the sensing fiber. .

[0045] For the aforementioned system, in ordinary single-mode fiber, the generation of the Brillouin scattering signal essentially depends on the stimulated Brillouin scattering interaction between the pump light and the backscattered light at local locations within the fiber. Since the intensity E2 of the pump light is fixed, the fundamental factor affecting the intensity of the Brillouin signal is the intensity of the backscattered Rayleigh signal.

[0046] Based on the same inventive concept, such as Figure 4 As shown, this application provides a Brillouin measurement method based on scattering enhancement, applicable to any of the Brillouin measurement systems described above, comprising the following steps: Step 101: Output probe light and pump light through the laser emission module. The probe light is continuous light and the pump light is intermittent light.

[0047] In this step, the laser emission module is activated, generating a continuous laser beam with a stable center frequency (e.g., f0) and extremely narrow linewidth, using a narrow-linewidth laser as the core light source. This laser beam is precisely split into two paths by a polarization-maintaining coupler (PMC) according to a preset splitting ratio (e.g., 50:50), which are respectively input into the probe light branch and the pump light branch. The probe light and pump light are output in a time-division manner by independently controlling the branches, and the two beams are different beams, thus creating a time difference in the output time. This ensures that the two beams meet precisely within the scattering-enhancing fiber and satisfy stimulated Brillouin scattering. (SBS) conditions, for example, include the following specific control logic and execution: First, start the probe light branch control: send a drive command to the microwave signal generator MSS to generate a high-frequency sinusoidal electrical signal with a frequency of fm. This electrical signal drives the first electro-optic modulator EOM1 to perform carrier-suppressed double-sideband modulation on the input continuous laser, outputting two sideband lights with frequencies of f0+fm and f0-fm, respectively. Then, control the first fiber amplifier EDFA1 to start, amplify the power of the two sideband lights, and ensure that the optical signal has long-distance transmission capability. The amplified sideband lights are filtered by the first optical filter OF1, retaining only one target sideband light (such as f0-fm) as the continuous probe light, which is output from the branch to the signal processing module. Simultaneously, control commands are sent to the arbitrary waveform generator (AWG) to generate an electrical pulse sequence with a specific pulse width (e.g., 50 ns) and repetition frequency. This electrical pulse sequence drives the second electro-optic modulator (EOM2) to modulate the input continuous laser into an optical pulse sequence (maintaining the center frequency f0). The second fiber amplifier (EDFA-2) is then activated, amplifying the optical pulse sequence to a high power level that excites the Brillouin effect. After the spontaneous emission noise is filtered out by the second optical filter (OF-2), a high-power, low-noise pump light pulse is formed and output to the signal processing module via a branch. Since the microwave signal generator emits continuous light while the arbitrary waveform generator emits intermittent light, the continuous and intermittent light create a time difference in the output light. This ensures that the probe light has sufficient time to form a backscattering enhancement signal in the scattering enhancement fiber, and also allows the pump light pulse to precisely meet this enhancement signal at a certain position in the fiber, satisfying the SBS frequency difference condition. This lays the foundation for efficient energy transfer, among which, For pump light frequency, To detect the frequency of light.

[0048] Another example, the specific control logic and execution include: first, starting the probe light branch control: sending a drive command to the microwave signal generator MSS to generate a high-frequency sinusoidal electrical signal with a frequency of fm. This electrical signal drives the first electro-optic modulator EOM1 to perform carrier-suppressed double-sideband modulation on the input continuous laser, outputting two sideband lights with frequencies of f0+fm and f0-fm, respectively; then controlling the first fiber amplifier EDFA1 to start, amplifying the power of the two sideband lights to ensure that the optical signal has long-distance transmission capability; the amplified sideband lights are filtered by the first optical filter OF1, retaining only one target sideband light (such as f0-fm) as the continuous probe light, which is output from the branch to the signal processing module. After a preset delay, the pump light branch control is activated: Based on the propagation speed of the probe light in the backscattering enhancement fiber, the fiber length, and the return time of the backscattering enhancement signal, a delay time is set (ensuring that the pump light and the backscattering enhancement signal meet at a preset position in the fiber). A control command is sent to the arbitrary waveform generator (AWG) to generate an electrical pulse sequence with a specific pulse width (e.g., 50 ns) and repetition frequency. This electrical pulse sequence drives the second electro-optic modulator (EOM2) to modulate the input continuous laser into an optical pulse sequence (with the center frequency maintained at f0). The second fiber amplifier (EDFA-2) is activated to amplify the optical pulse sequence to a high power level that excites the Brillouin effect. After the spontaneous emission noise is filtered out by the second optical filter (OF-2), a high-power, low-noise pump light pulse is formed and output from the branch to the signal processing module. Timing synchronization control: The controller coordinates the startup timing of the microwave signal generator and the arbitrary waveform generator in real time to ensure that the probe light outputs before the pump light, and that the output time difference between the two lights precisely matches the system design requirements—ensuring that the probe light has sufficient time to form a backscattering enhancement signal in the scattering enhancement fiber, and that the pump light pulse and the enhancement signal precisely meet at various positions in the fiber, satisfying the SBS frequency difference condition. This lays the foundation for efficient energy transfer, among which, For pump light frequency, To detect the frequency of light.

[0049] Step 102: Receive the probe light and the pump light through a scattering enhancement fiber, so that the backscattering enhancement light generated by the probe light meets the pump light, generating Brillouin scattering light with gain information.

[0050] In this step, generating Brillouin scattered light with gain information includes: injecting the probe light into the scattering enhancement fiber to obtain a backscattering enhancement light signal and a backscattering Rayleigh scattering component light signal; adding the backscattering enhancement light signal and the backscattering Rayleigh scattering component light signal to obtain a backscattering enhancement signal; and injecting the pump light into the scattering enhancement fiber so that the pump light meets the backscattering enhancement signal to generate the Brillouin scattered light.

[0051] In this step, the process of generating Brillouin scattered light with gain information is based on the structural characteristics of scattering-enhancing fiber and the physical mechanism of stimulated Brillouin scattering (SBS). It is achieved through a three-stage progressive process of "optical signal injection - scattering enhancement - energy transfer". The specific details are as follows: Probe light injection and double scattering signal generation: After polarization equalization by the signal processing module and meeting, the continuous probe light is injected into the scattering-enhancing fiber (such as WFBG fiber with an inscribed identical weak grating array) through the main optical path circulator. As the probe light propagates along the optical fiber towards the far end, it encounters periodically distributed weak grating units within the fiber. Because the reflection wavelength of the weak gratings matches the wavelength of the probe light, each weak grating unit produces a directional backscattering, forming a discretely distributed backscattering-enhanced optical signal. The strength of this signal is determined by the reflectivity (0.005%-0.01%) and distribution density of the weak gratings, and it exhibits stable and controllable characteristics. On the other hand, during transmission through the fiber, the probe light interacts with the non-uniform distribution of impurities in the fiber core, generating the fiber's inherent backscattering Rayleigh scattering component. Although this signal is weaker, it exhibits a full-link distribution. Both types of signals propagate synchronously towards the near end along the fiber, laying the foundation for subsequent enhancement and superposition. The superposition of these two scattering signals forms the backscattering-enhanced signal: As the probe light returns towards the near end, the discrete backscattering-enhanced optical signals generated by each weak grating unit and the full-link distributed backscattering Rayleigh scattering component converge along the same optical path, forming the backscattering-enhanced signal. For example, when the probe light propagates along the scattering-enhancing fiber to the i-th weak grating unit, the unit generates a back reflection component at the grating from the far end to the near end. The back reflection components generated by each weak grating unit along the line are superimposed and converged in the near-end direction to form a stable and controllable back reflection signal. (t). The probe light also produces an inherent backscattering Rayleigh component within the optical fiber. (t). Therefore, at the receiving end, the discrete weakly reflected backscattered light from the WFBG weak grating array combines with the inherent Rayleigh backscattered enhanced light from the scattering-enhanced fiber to form a backscattered enhanced signal: The Pprobe(t) mentioned above, as the final probe light in the Brillouin measurement link of the present invention, directly uses the enhanced backward signal as the probe light input for SBS interaction, thereby improving the probe light substrate of Brillouin measurement.

[0052] The enhanced signal strength is significantly better than the scattered signal from traditional single-mode fiber—wherein, the reflectance coefficient of the weak grating (e.g., 10) is significantly lower. -4 ) is much larger than the Rayleigh scattering coefficient (10 -7The backscattering component becomes the core contributor to signal enhancement, while the Rayleigh scattering component fills the signal gaps between weak gratings, ensuring a continuous distribution of the enhanced signal across the entire fiber length. The resulting backscattered enhanced signal possesses both high intensity and full-link coverage, providing a high-quality probe light substrate for SBS interaction. Pump light injection encounters the SBS to generate Brillouin scattering: the pump light pulse, time-division multiplexed with the probe light, propagates towards the far end after being injected into the scattering-enhanced fiber via the same optical path, its propagation direction opposite to the backscattered enhanced signal. When the pump light pulse (the pump light frequency is...)... ) and the backscattering enhancement signal (the frequency of the backscattering enhancement signal is When the optical fibers meet at a certain position z in the fiber, if the frequency difference between the two is ( This is exactly equal to the Brillouin frequency shift of the fiber at that location. (If the relationship is linear with the temperature T and strain ε at that location), then a strong stimulated Brillouin scattering interaction will be triggered, that is, the following condition will be met. Under these conditions, the energy of the pump light is efficiently transferred to the backscattering enhancement signal through the phonon energy transfer effect, resulting in a significant Brillouin gain (or loss) for the probe light at that location. The amplitude and phase changes of this gain are directly related to the temperature and strain at that location. After the backscattering enhancement signal encounters the SBS at various points along the entire link, it is converted into Brillouin scattered light carrying the overall link gain information. This light continues to propagate along the near end of the fiber and is eventually output to the analysis module via the main optical path circulator.

[0053] The effects of this process: Firstly, it enhances the intensity of the probe light from the source, overcoming the bottleneck of weak signals. Through the design of superimposed dual-scattered signals, discrete strong reflection signals are organically combined with continuous weak scattering signals. This not only utilizes a weak grating to achieve a significant increase in signal intensity but also supplements the continuity of signal distribution through Rayleigh scattering. This solves the problem of weak signals caused by traditional systems relying solely on Rayleigh scattering, providing a high-intensity, full-coverage probe light foundation for SBS energy transfer. Secondly, it enhances SBS energy transfer efficiency and improves signal gain discernibility. The high-intensity characteristics of backscattering enhance the signal, allowing for more complete energy transfer between the pump and probe lights. The variation in Brillouin gain (or loss) is significantly increased, making it easier to distinguish from noise compared to the gain variation of traditional weak signals. This advantage reduces reliance on auxiliary methods such as signal averaging and gain amplification, directly improving the detectability of Brillouin scattered light. Achieving precise correlation between gain information and physical quantities: The occurrence of SBS energy transfer strictly depends on the matching of frequency difference and Brillouin frequency shift, which is strongly correlated with temperature and strain. Therefore, the gain change of Brillouin scattered light accurately reflects the physical quantity information at each location in the optical fiber. Simultaneously, the backscattering enhances the end-to-end continuity of the signal, ensuring effective SBS energy transfer at every location on the fiber, achieving full coverage of distributed temperature / strain measurements and avoiding signal dead zones. Balancing long-distance transmission and signal quality: Precise control of the weak grating reflectivity (≤0.01%) enhances the signal while avoiding additional link losses caused by excessive reflection, ensuring the long-distance transmission capability of pump and probe light. The superposition design of the two types of scattered signals maintains signal stability during long-distance transmission, enabling the system to maintain high signal quality and measurement accuracy in long-distance distributed monitoring scenarios.

[0054] Step 103: Receive the Brillouin scattered light through the analysis module and analyze the Brillouin scattered light to obtain gain information; determine the temperature and strain information of the scattering enhancement fiber based on the gain information.

[0055] In this process, the analysis module is the core data parsing component of the entire measurement system. Through a full-chain processing of "signal purification, conversion, positioning, spectrum construction, and physical quantity conversion," the analysis module transforms the Brillouin scattered light carrying distributed information into precise temperature and strain data.

[0056] Furthermore, the gain information includes a Brillouin gain spectrum; analyzing the Brillouin scattered light with gain information to obtain the gain information includes: performing photoelectric conversion on the Brillouin scattered light to obtain a time-domain electrical signal; determining the position of the Brillouin scattered light based on the time-domain electrical signal; and determining the Brillouin gain spectrum based on the position of the Brillouin scattered light and the preset frequency difference corresponding to that position.

[0057] Specifically, the Brillouin scattered light first enters the third optical filter OF3. The center frequency of this filter precisely matches the frequency of the Brillouin scattered light signal, efficiently filtering out residual pump light that did not participate in stimulated Brillouin scattering (SBS), ambient stray light, and other interference light introduced during transmission, ensuring that only pure, effective signals enter subsequent stages. The filtered and purified Brillouin scattered light is injected into a high-responsivity, low-dark-current photodetector PD. Based on the photoelectric effect, the detector converts the power change of the optical signal into a corresponding analog electrical signal (current or voltage signal), and the amplitude and phase changes of the signal completely preserve the SBS gain characteristics at each location in the optical fiber. The analog electrical signal is then transmitted to the data acquisition card DAQ. The acquisition card performs high-speed quantization of the analog electrical signal at a preset high sampling rate (adapting to the signal's time-domain characteristics) and high sampling accuracy (e.g., 16 bits or higher), converting it into a discrete digital signal and buffering it according to a time sequence to avoid signal distortion. In this embodiment, the calculation formula for the enhanced scattering signal is: ; In the formula, Backscattered signal intensity, where A is the incident light power and n is the effective refractive index of the optical fiber. , It is related to the pulse width and satisfies Where W is the probe pulse width and c is the speed of light in a vacuum. Let m and k be the reflectance of the scattering enhancement points. Time-resolved signal location: The controller calls a time-resolved algorithm, combining the propagation speed of light in the scattering enhancement fiber (v=c / n, where c is the speed of light in vacuum and n is the effective refractive index of the fiber), to perform position correlation on the time-domain digital signal recorded by the data acquisition card. Since the return time of Brillouin scattered light from different positions z in the fiber differs (the return time of the signal at the far end is longer than that at the near end), the controller calculates the relationship between the signal arrival time t at the detector and the propagation speed v (z=vt / 2, divided by 2 because the optical signal travels back and forth). This allows for precise determination of the fiber spatial position corresponding to each segment of the time-domain electrical signal, achieving a one-to-one mapping between "signal and position," and obtaining the Brillouin gain response G(z,Δf), laying the foundation for distributed measurement. Frequency difference scanning constructs the Brillouin gain spectrum: For each located fiber position z, the controller initiates frequency difference scanning (… Scanning process – by adjusting the output frequency of the microwave signal generator in the laser emission module Changing the frequency difference between the probe light and the pump light At the same time, record the location in different The gain value of the electrical signal is calculated from the amplitude of the digital signal. Since the SBS gain only reaches its peak when Δf equals the Brillouin frequency shift ν_B(T,ε) at that position, the controller fits different Δf values ​​at the same position with the corresponding gain values ​​to plot the Brillouin gain spectrum (BGS) at that position. The spectrum is plotted with the frequency difference on the horizontal axis and the gain value on the vertical axis. The frequency difference corresponding to the peak value is the Brillouin frequency shift (BFS) at that position, thus completing the core extraction of gain information.

[0058] Furthermore, the gain information includes a Brillouin gain spectrum; determining the temperature and strain information of the scattering-enhancing fiber based on the gain information includes: obtaining a linear equation solution method based on the Brillouin gain spectrum, and obtaining the temperature and strain information of the scattering-enhancing fiber based on preset calibration information and the linear equation.

[0059] Specifically, after acquiring the Brillouin gain spectrum (BGS) at each location along the entire fiber optic cable, the controller performs the conversion between temperature and strain information according to the following logic, relying entirely on calibration information and linear relationships to achieve accurate solutions: The core role of the preset calibration information: The preset calibration information consists of key system parameters obtained through prior experiments, including the reference Brillouin frequency shift ν_B(T0,ε0) at reference temperature T0 and reference strain ε0, as well as the temperature coefficient α (unit: MHz / ℃) and strain coefficient β (unit: MHz / με) of the Brillouin frequency shift. These parameters are obtained through multiple measurements and calibrations under known temperature and strain conditions, and are the core basis for realizing the "frequency shift-physical quantity" conversion, ensuring the accuracy of the measurement results. Linear equation solution logic: The controller first extracts the Brillouin frequency shift value corresponding to the peak value from the Brillouin gain spectrum (BGS) at each location. Then, substituting the equations into the linear relationship between Brillouin frequency shift and temperature and strain:

[0060] Since only temperature T and strain ε are unknowns in the equation, the controller can accurately calculate the actual temperature T and strain ε at that location by using a preset linear equation solving method (such as the least squares method or the direct substitution method) combined with calibration coefficients α and β. After performing the above calculations sequentially for each location along the entire fiber, distributed temperature / strain distribution data along the fiber length is finally generated, which can be further used to generate intuitive distribution maps.

[0061] The technical advantages of this embodiment are as follows: Ensuring the accuracy and reliability of data analysis: Through secondary filtering of the third optical filter, low-noise photoelectric conversion, and high-precision data acquisition, the impact of noise and interference on the signal is minimized, providing a high signal-to-noise ratio data foundation for spectrum construction. The combination of time-resolved algorithms and frequency difference scanning ensures the positional accuracy and peak identification of the Brillouin gain spectrum (BGS), significantly reducing the extraction error of the Brillouin frequency shift (BFS). Achieving full coverage and high resolution of distributed measurements: Relying on the precise mapping of "signal-position," independent gain spectrum analysis and physical quantity conversion can be performed on each spatial point within the entire length of the optical fiber, with no measurement blind spots. Combining the distribution density of weak gratings in the scattering-enhancing fiber (e.g., 5m spacing) with the high sampling rate of the data acquisition card, high spatial resolution distributed measurements can be achieved, meeting the needs of long-distance, refined monitoring (e.g., oil and gas pipeline leak monitoring, bridge strain distribution monitoring). Simplified calculation logic and improved measurement efficiency: Utilizing the linear relationship between Brillouin frequency shift and temperature and strain, the solution is directly obtained through preset calibration coefficients, avoiding complex nonlinear fitting processes and reducing computational complexity. Full-process automated analysis (from signal acquisition to spectrum generation and physical quantity conversion) requires no manual intervention, significantly shortening data processing time and improving the system's real-time monitoring capabilities. Enhanced engineering applicability of measurement results: The final output of distributed temperature / strain data and intuitive spectra can directly provide decision-making basis for engineering applications (such as determining the location of stress concentration in infrastructure and temperature anomaly areas in geological disasters). The stability of the linear equation solution method and the calibrability of the calibration information ensure the repeatability and comparability of the measurement results, adapting to the needs of long-term, multi-scenario engineering monitoring.

[0062] In steps 101-103, through the coordinated process of "time-division output of optical signal → enhancement of Brillouin scattered light → analysis of physical quantities", two major effects are achieved: First, it breaks through the bottleneck of weak backscattered signal in traditional Brillouin measurement. After the backscattered enhanced signal and the pump light signal undergo SBS, a signal carrying Brillouin gain is generated, which improves the signal strength and signal-to-noise ratio. Second, it accurately completes the extraction of distributed temperature and strain information along the optical fiber, realizing high reliability and high precision full-link physical quantity monitoring.

[0063] Figure 5a The backscattering intensity distribution of the scattering-enhanced fiber; Figure 5b This represents the inherent backscattering Rayleigh scattering intensity distribution of a single-mode fiber. Based on the above scheme, simulations were performed using MATLAB with the following parameters: fiber length 1 km, scattering enhancement point (grating) spacing 5 m, and pulse width 50 ns. Figure 5a and Figure 5bAs can be seen, at the scattering enhancement point, the backscattering intensity of the scattering-enhanced fiber is significantly higher than that of the ordinary single-mode fiber, thereby achieving backscattering enhancement and providing a basis for scattered light with a higher signal-to-noise ratio for subsequent Brillouin signal extraction.

[0064] This invention enhances the backscattered signal by introducing scattering-enhancing fiber, thus overcoming the inherent weakness of weak Rayleigh backscattered signal in optical fibers and achieving Brillouin scattering signal enhancement. The process by which scattering-enhancing fiber enhances the Brillouin scattering signal compared to ordinary single-mode fiber is as follows: Figure 3 As shown, Figure 3 (a) Taking the 0 to z1 interval in a single-mode fiber as an example, the Brillouin scattering signal is generated by the SBS of the inherent backscattered Rayleigh light and the pump light; Figure 3 (b) illustrates the process of pump light energy being transferred to backscattered Rayleigh light in a single-mode fiber, and gives the intensity E4 of the Brillouin scattering signal at this time. Figure 3 (c) Taking the section from 0 to z1 of the scattering-enhanced fiber as an example, the function of the weak reflection grating at z1 is analyzed. After the probe light is reflected by the weak reflection grating, it combines with the backscattered Rayleigh light and is transmitted in the form of backscattered enhanced light, which causes SBS with the pump light that is transmitted in the opposite direction. Figure 3 (d) illustrates the process of pump light energy being transferred to backscattering enhancement light in the scattering-enhanced fiber, and gives the intensity E5 of the Brillouin scattering signal at this time. By comparing the two, it can be seen that the Brillouin scattering signal intensity E5 is greater than E4, thus verifying that using scattering-enhanced fiber as the sensing fiber can improve the intensity of the Brillouin scattering signal. Wherein, E1: backscattered Rayleigh light intensity, E2: pump light intensity, E3: composite signal intensity, E4: intensity distribution of the Brillouin signal obtained using single-mode fiber, and E5: intensity distribution of the Brillouin signal obtained using SE-SMF.

[0065] Assuming PB is the Brillouin signal power, its relationship with the Rayleigh scattering coefficient... and weak fiber grating reflectivity The formula for PB is as follows:

[0066] middle To detect optical power, Let be the Brillouin gain coefficient, and formula (4) represent the signal light power corresponding to the backscattering enhanced fiber (WFBG). The WFBG used in this invention has a reflection coefficient of 10⁻⁴, while the Rayleigh scattering coefficient is generally 10⁻⁷. Using the WFBG as the sensing fiber not only improves the intensity of the backscattered enhanced light, but also... It has been greatly improved.

[0067] After stimulated Brillouin scattering of the backscattering enhancement signal and the pump light signal, the sensing pulse carrying temperature / strain information along the optical fiber is the Brillouin signal. Compared with traditional single-mode optical fiber, scattering enhancement fiber has a significant effect on improving the intensity of Brillouin scattering signal when used as a sensing fiber.

[0068] To further evaluate the performance improvement effect of this invention on the Brillouin scattering system, the signal-to-noise ratio (SNR) of the system is analyzed below. The SNR expressions for single-mode fiber and scattering-enhanced fiber are shown in equations (5) and (6), respectively. (5) (6) In the formula, k is Boltzmann's constant, and T is the absolute temperature. For the bandwidth of the photodetector, Where is the load resistance, and q is the electron charge. The average signal photocurrent of the Brillouin sensor system. For the dark current of the photodetector, The laser linewidth is given. Since the reflection coefficient (10⁻⁴) of the backscattering-enhanced fiber is much greater than the Rayleigh scattering coefficient (10⁻⁷), this invention uses the backscattering-enhanced fiber as the sensing fiber in the system, which not only improves the intensity of the backscattered enhanced light but also... It has been greatly improved, and it can be seen from formulas (5) and (6) that The significant enhancement will directly improve the system signal-to-noise ratio.

[0069] The Brillouin distributed measurement system based on scattering-enhanced fiber described in this invention is not limited to the structure and detection method shown in the above embodiments. In addition to the direct detection scheme, this invention can also employ local heterodyne, self-heterodyne, and other methods to acquire and demodulate the Brillouin signal; the corresponding optical path device configurations (such as the introduction method of probe light and pump light, the coupler / circulator connection method, the filtering and amplification structure, etc.) can be equivalently replaced and combined according to actual application requirements. Any technical solution that utilizes "enhanced backscattering light" as the probe light to increase the intensity of the stimulated Brillouin scattering signal and thus improve the distributed measurement performance should fall within the protection scope of this invention. The implementation of the scattering-enhancing fiber described in this invention is not limited to inscribing a WFBG array inside the fiber. Besides WFBG, this invention also includes, but is not limited to, other methods of constructing discrete scattering enhancement points in the fiber, such as: forming weak reflection points or weak scattering structures in the core / cladding, forming discrete reflection points using laser inscription / microstructure modification, using random / quasi-random weak grating structures, or using other backscattering enhancement structures capable of generating a backscattering intensity higher than the inherent Rayleigh scattering intensity at predetermined locations. The spacing, length, reflectivity (or equivalent scattering intensity), and distribution pattern (periodic, aperiodic, segmented variable, etc.) of the aforementioned scattering enhancement points can all be designed and adjusted according to system resolution, range, and signal-to-noise ratio requirements, and do not constitute a limitation of this invention.

[0070] It should be noted that the method in this embodiment can be executed by a single device, such as a computer or server. The method can also be applied in a distributed scenario, where multiple devices cooperate to complete the task. In such a distributed scenario, one of these devices may execute only one or more steps of the method in this embodiment, and the multiple devices will interact with each other to complete the method described.

[0071] It should be noted that the above description describes some embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0072] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement a Brillouin measurement method based on scattering enhancement as described in any of the above embodiments.

[0073] Figure 6 This embodiment illustrates a more specific hardware structure of an electronic device. The device may include a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, memory 1020, input / output interface 1030, and communication interface 1040 are interconnected internally via the bus 1050.

[0074] The processor 1010 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0075] The memory 1020 can be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 1020 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program code is stored in the memory 1020 and is called and executed by the processor 1010.

[0076] The input / output interface 1030 is used to connect input / output modules to realize information input and output. Input / output modules can be configured as components within the device (not shown in the figure) or externally connected to the device to provide corresponding functions. Input devices may include keyboards, mice, touchscreens, microphones, various sensors, etc., while output devices may include displays, speakers, vibrators, indicator lights, etc.

[0077] The communication interface 1040 is used to connect a communication module (not shown in the figure) to enable communication between this device and other devices. The communication module can communicate via wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0078] Bus 1050 includes a pathway for transmitting information between various components of the device, such as processor 1010, memory 1020, input / output interface 1030, and communication interface 1040.

[0079] It should be noted that although the above-described device only shows the processor 1010, memory 1020, input / output interface 1030, communication interface 1040, and bus 1050, in specific implementations, the device may also include other components necessary for normal operation. Furthermore, those skilled in the art will understand that the above-described device may only include the components necessary for implementing the embodiments of this specification, and not necessarily all the components shown in the figures.

[0080] The electronic devices described in the above embodiments are used to implement a Brillouin measurement method based on scattering enhancement in any of the foregoing embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0081] Based on the same inventive concept, corresponding to the methods of any of the above embodiments, this application also provides a non-transitory computer-readable storage medium storing computer instructions for causing the computer to execute a Brillouin measurement method based on scattering enhancement as described in any of the above embodiments.

[0082] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0083] The computer instructions stored in the storage medium of the above embodiments are used to cause the computer to execute a Brillouin measurement method based on scattering enhancement as described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0084] It is understood that before using the technical solutions of the various embodiments in this disclosure, users will be informed of the type, scope of use, and usage scenarios of the personal information involved in an appropriate manner, and user authorization will be obtained.

[0085] For example, upon receiving a user's active request, a prompt message is sent to the user to explicitly inform them that the requested operation will require the acquisition and use of the user's personal information. This allows the user to independently choose, based on the prompt message, whether to provide personal information to the software or hardware such as electronic devices, applications, servers, or storage media performing the operations of this disclosed technical solution.

[0086] As an optional but not limited implementation, in response to a user's active request, sending a prompt message to the user can be done via a pop-up window, where the prompt message can be presented in text format. Furthermore, the pop-up window can also include a selection control allowing the user to choose "agree" or "disagree" to provide personal information to the electronic device.

[0087] It is understood that the above notification and user authorization process are merely illustrative and do not constitute a limitation on the implementation of this disclosure. Other methods that comply with relevant laws and regulations may also be applied to the implementation of this disclosure.

[0088] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application is limited to these examples; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0089] Additionally, to simplify the description and discussion, and to avoid obscuring the embodiments of this application, the well-known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided drawings. Furthermore, the apparatus may be shown in block diagram form to avoid obscuring the embodiments of this application, and this also takes into account the fact that the details of the implementation of these block diagram apparatuses are highly dependent on the platform on which the embodiments of this application will be implemented (i.e., these details should be fully understood by those skilled in the art). While specific details (e.g., circuits) have been set forth to describe exemplary embodiments of this application, it will be apparent to those skilled in the art that the embodiments of this application can be implemented without these specific details or with variations thereof. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0090] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may be used with the embodiments discussed.

[0091] Any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application shall be included within the protection scope of this application.

Claims

1. A Brillouin measurement system based on scattering enhancement, characterized in that, include: A laser emitting module is used to output probe light and pump light, wherein the probe light is continuous light and the pump light is intermittent light; A backscattering enhancement fiber is used to receive the probe light and the pump light, so that the backscattering enhancement light generated by the probe light meets the pump light to generate Brillouin scattered light with gain information. An analysis module is used to receive the Brillouin scattered light, analyze the Brillouin scattered light to obtain gain information, and determine the temperature and strain information of the scattering-enhancing fiber based on the gain information.

2. The system according to claim 1, characterized in that, The scattering enhancement fiber is a fiber Bragg grating fiber, which includes a periodically distributed array of identical weak gratings. The reflectivity range for each weak grating is set to 0.00006%-0.01%.

3. The system according to claim 1, characterized in that, The laser emitting module includes a narrow-line laser and a polarization-maintaining coupler, wherein the polarization-maintaining coupler splits the incident light from the narrow-line laser into a probe light branch and a pump light branch. The probe light branch includes: a first electro-optic modulator, a microwave signal generator, a first fiber amplifier, and a first optical filter; the microwave signal generator is used to generate an electrical signal to drive the first electro-optic modulator to output two sideband lights; the first fiber amplifier is used to amplify the two sideband lights and inject them into the first optical filter; the first optical filter is used to select one sideband light as the probe light and inject it into the scattering enhancement fiber. The pump light branch includes: a second electro-optic modulator, an arbitrary waveform generator, a second fiber amplifier, and a second optical filter; the arbitrary waveform generator is used to generate an electrical pulse sequence to drive the second electro-optic modulator to output an optical pulse sequence; the second fiber amplifier is used to amplify the optical pulse sequence and inject it into the second optical filter; the second optical filter is used to filter out the spontaneous emission noise of the optical pulse sequence to form pump light and inject it into the scattering enhancement fiber; The microwave signal generator generates an electrical signal to drive the first electro-optic modulator to output sideband light as continuous light, and the arbitrary waveform generator drives the second electro-optic modulator to output a sequence of light pulses as discontinuous light.

4. The system according to claim 1, characterized in that, The system further includes a signal processing module, which processes the probe light emitted from the probe light branch and the pump light emitted from the pump light branch and injects them into the scattering enhancement fiber, while simultaneously receiving the Brillouin scattered light reflected from the scattering enhancement fiber and injecting it into the analysis module.

5. The system according to claim 1, characterized in that, The signal processing module includes: a polarization scrambler, an optical coupler, and a main optical path circulator; The polarization disruptor is used to polarize the probe light and the pump light to achieve polarization equalization and inject them into the optical coupler; The optical coupler is used to couple the probe light and the pump light and inject them into the main optical path circulator; The main optical path circulator is used to inject the probe light and the pump light into the scattering enhancement fiber and to receive the Brillouin scattered light reflected by the scattering enhancement fiber and inject it into the analysis module.

6. The system according to claim 1, characterized in that, The analysis module includes a third optical filter, a photodetector, a data acquisition card, and a controller connected in sequence. The third optical filter is used to filter out interference light from the Brillouin scattering light and inject it into the photodetector; The photodetector is used to convert the Brillouin scattered light into an electrical signal and inject it into the data acquisition card; The data acquisition card is used to convert the electrical signal into a digital signal for recording; The controller is used to plot and analyze the Brillouin spectrum of the recorded digital signal to obtain gain information; and to determine the temperature and strain information of the scattering enhancement fiber based on the gain information.

7. A Brillouin measurement method based on scattering enhancement, applicable to the Brillouin measurement system based on scattering enhancement as described in any one of claims 1-6, characterized in that, include: The laser emitting module outputs a probe light and a pump light, wherein the probe light is continuous light and the pump light is intermittent light; The probe light and the pump light are received by a scattering enhancement fiber, so that the backscattering enhancement light generated by the probe light meets the pump light to generate Brillouin scattered light with gain information. The Brillouin scattered light is received by the analysis module and analyzed to obtain gain information; based on the gain information, the temperature and strain information of the scattering-enhancing fiber are determined.

8. The method according to claim 7, characterized in that, The probe light and the pump light are received through a scattering-enhancing fiber, so that the backscattering-enhancing light generated by the probe light meets the pump light, producing Brillouin scattered light with gain information, including: The probe light is injected into the scattering-enhancing fiber to obtain a backscattering-enhanced optical signal and a backscattering Rayleigh component optical signal. The backscattering enhanced optical signal and the backscattering Rayleigh component optical signal are added together to obtain the backscattering enhanced signal; The pump light is injected into the scattering-enhancing fiber to allow the pump light to undergo phonon energy transfer with the backscattering-enhancing signal, thereby generating the Brillouin scattered light.

9. The method according to claim 7, characterized in that, The gain information includes the Brillouin gain spectrum; Analysis of the Brillouin scattered light yields gain information, including: The Brillouin scattered light is photoelectrically converted to obtain a time-domain electrical signal; The position of the Brillouin scattered light is determined based on the time-domain electrical signal. The Brillouin gain spectrum is determined based on the position of the Brillouin scattered light and the preset frequency difference corresponding to that position.

10. The method according to claim 7, characterized in that, The gain information includes the Brillouin gain spectrum; Based on the gain information, the temperature and strain information of the scattering-enhancing fiber are determined, including: Based on the Brillouin gain spectrum, determine the linear equation; The temperature information and the strain information are obtained based on the preset calibration information and the linear equation.

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