A MOMES and FBG fusion sensing system based on tunable laser array

Abstract

The present invention relates to the field of optical fiber sensing technology, and more specifically to a MOMES and FBG fusion sensing system based on an adjustable laser array. A multi-wavelength tunable laser array light source is used to generate fast broadband frequency-sweeping laser light, which is split into M outputs via a multi-path planar optical waveguide splitter coupler. Each output end is connected to N FBG sensor arrays and one MOMES sensor, and the reflected light of the sensing signal is received by the corresponding photodetector. After data processing by a photoelectric converter, a logarithmic amplifier, an analog-to-digital converter, and an FPGA-compatible algorithm platform, the peaks and troughs of the reflected spectrum data at each wavelength point are simultaneously found. The peak data is used to demodulate the FBG sensor array, and the trough data is used to demodulate the MOMES sensor. The optical path structure and algorithm design of the system achieve synchronous demodulation of the FBG and MOMES sensors, significantly improving the system's compatibility and computational efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber sensing, and in particular to a MOMES and FBG fusion sensing system based on an adjustable laser array. Background Art

[0002] The rapid development of new-generation information technology has made sensing technology increasingly critical in the future field of information technology. Among them, fiber optic sensing, as an important branch, plays a vital role in major scientific and engineering research.

[0003] However, the fiber optic sensing market accounts for a relatively small proportion, resulting in most of its lasers being used after adjusting the drive circuit based on communication lasers. The standard wavelength bands of these lasers are narrow and cannot be customized, which limits the demodulation capabilities of fiber grating (FBG) and MOMES sensors. FBG sensors are based on reflection spectrum peak detection to sense changes. Their advantage lies in wavelength division multiplexing technology, but they are prone to breakage when measuring structural mechanical parameters. MOMES sensors are based on interference, measuring changes in the spacing between the troughs of the interference spectrum. They have a large variation space and are suitable for large-scale, high-precision measurements, but are difficult to connect in series. Both require lasers to continuously emit swept light for detection. The principle is based on spectral perception, but due to the single demodulation nature of existing systems, they cannot simultaneously connect to two sensors and complete demodulation. The two systems need to be demodulated separately and then integrated, resulting in problems such as inability to absolutely synchronize data, high costs, and complex systems, which limit application scenarios. Summary of the Invention

[0004] In view of the above-mentioned technical deficiencies, the purpose of the present invention is to provide a MOMES and FBG fusion sensing system based on an adjustable laser array to solve the problem in the prior art that FBG sensors and MOMES sensors cannot be demodulated simultaneously in the same channel.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] In the first aspect, a MOMES and FBG fusion sensing system based on an adjustable laser array includes: a multi-wavelength tunable laser array light source, a multi-channel planar optical waveguide branch coupler, a MOMES sensor, an FBG sensor array, a photodetector, a logarithmic amplifier, an analog-to-digital converter, an FPGA-compatible algorithm platform, and a host computer display platform; the laser output interface of the multi-wavelength tunable laser array light source is connected to the input end of the multi-channel planar optical waveguide branch coupler; the output end of the multi-channel planar optical waveguide branch coupler is connected to the FBG sensor array, and the end of the FBG sensor array is connected to the MOMES sensor; the return end of the multi-channel planar optical waveguide branch coupler is sequentially connected to the photodetector, the logarithmic amplifier, and the analog-to-digital converter; the digital signal output by the analog-to-digital converter is transmitted to the FPGA-compatible algorithm platform.

[0007] Preferably, in a possible implementation of the first aspect, the laser array light source is composed of a 4×6 series-parallel matrix distributed monolithically integrated multiple multi-wavelength distributed feedback unit laser array, which is then merged into an optical waveguide output through a two-stage cascaded 2-in-1 Y-branch active combining waveguide structure, and a semiconductor optical amplifier is integrated at the front end of the chip light output to balance the final output swept frequency optical power. Each unit laser's wavelength is designed to emit a lasing grating at 2nm intervals. The accompanying laser hardware control circuit controls the corresponding unit laser according to wavelength, completing a wavelength sweep across the 2nm interval and then switching to the next unit laser with the adjacent wavelength. Twenty-four unit lasers can sequentially cover a 48nm wavelength range, generating a continuously variable wavelength swept optical signal. The conditioned tunable laser signal continuously sweeps, outputting trigger signals at a fixed frequency interval of 5 GHz (approximately 8 pm). The sweeping light passes through the input of a multi-channel planar optical waveguide splitter coupler, which contains M groups of 1×2 splitters. The incident light is first split into M paths, which are then simultaneously output by the M 1×2 splitters. One of the output paths is first connected to an FBG sensor array, followed by a MOMES sensor at the end of the FBG sensor array. Light that meets the FBG reflection conditions is first continuously reflected by the array grating, forming a continuous interference spectrum at the MOMES sensor at the end. The data collected at the acquisition end is triggered at 5 GHz frequency intervals, forming a continuous tunable laser reflection spectrum.

[0008] Preferably, in a possible implementation of the first aspect, the photodetector receives a continuous FBG reflection spectrum and a MOMES sensor interference spectrum, and the received optical signal is first converted into a current signal by a photoelectric converter, and then amplified by a logarithmic amplifier to enhance the dynamic range, and then converted from an analog signal to a digital signal and input into an FPGA-compatible algorithm platform for processing.

[0009] Preferably, in a possible implementation of the first aspect, the FPGA-compatible algorithm platform drives the analog-to-digital conversion chip, and one sweep cycle can obtain spectral data with a 5 GHz spacing, 1216 points, and a total bandwidth of 48.4 nm. These data completely include the FBG sensor array reflection spectrum and the MOMES sensor interference spectrum. After each acquisition is completed, the data is transmitted in real time to two FPGA_FIFO resources. The two FIFO resources containing spectral data are released in parallel. One of the FIFO resources searches for a maximum point for data above the threshold according to a set threshold, and shifts 4 sampling points to the left and right of the maximum point. The other resource searches for a minimum point for data below the threshold according to the set threshold, and shifts 4 sampling points to the left and right of the minimum point. Finally, binomial fitting is performed on the two data channels containing multiple peak and trough sampling points to obtain continuous peak data and continuous trough data. The frequency shift of the peak data represents a change in the corresponding FBG sensor array sensor, and the data of the distance between consecutive adjacent troughs represents a change in the interference cavity length.

[0010] The beneficial effects of the present invention are as follows: a fiber Bragg grating (FBG) sensor array and a micro-opto-electromechanical (MOMES) sensor are combined in one channel by using a band-matched 48.4nm bandwidth laser array, thereby improving the compatibility of sensors based on various principles; an array laser chip is used to achieve the output of a single-mode fast wavelength sweep signal with good characteristics and a 48nm bandwidth through high-density integration of 24 multi-wavelength DFB unit lasers on a single chip and in combination with a corresponding hardware control circuit; the output power is balanced through a front-end integrated SOA to achieve the output of a wavelength synchronization signal; and two fiber Bragg grating (FBG) sensor array spectra with different characteristics and the micro-opto-electromechanical (MOMES) sensor spectrum are synchronously subjected to feature extraction and data processing without interfering with each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0012] Figure 1 The present application provides a structural schematic diagram of a MOMES and FBG fusion sensing system based on an adjustable laser array.

[0013] Figure 2 This application provides a structural schematic diagram of an i×j matrix structured tunable multi-wavelength distributed feedback laser array chip and a 4×6 laser array chip diagram for generating broadband fast continuous frequency sweeping laser signals.

[0014] Figure 3 Fiber Bragg grating (FBG) and micro-opto-electromechanical (MOMES) spectra in the same channel are provided for this application.

[0015] Figure 4 A compatibility algorithm software flow chart is provided for this application. DETAILED DESCRIPTION

[0016] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0017] Example 1: Figure 1 As shown, the present invention provides a MOMES and FBG fusion sensing system based on an adjustable laser array, including a multi-wavelength tunable laser array light source, a multi-path planar optical waveguide branch coupler, a MOMES sensor, an FBG sensor array, a photodetector, a logarithmic amplifier, an analog-to-digital converter, an FPGA-compatible algorithm platform, and a host computer display platform.

[0018] Specifically, a multi-wavelength tunable laser array light source consists of multiple independently tunable lasers, each capable of outputting optical signals at different wavelengths. It utilizes a multi-wavelength tunable Q-switched fiber laser, including a semiconductor laser with pigtails, a wavelength division multiplexer, single-mode erbium-doped fiber, a fiber isolator, a fiber coupler, a fiber polarization controller, and a tuning device.

[0019] The multi-path planar waveguide split coupler splits the optical signals output by a multi-wavelength tunable laser array and couples them to different sensor channels. Using a planar waveguide structure with multiple input and output ports, the coupler evenly distributes the input optical signal to each output port. This coupler offers low loss and high stability, ensuring the quality and stability of optical signals during transmission.

[0020] The MOMES sensor utilizes micro-opto-electromechanical (MOMES) technology to detect and convert optical signals. This MOMES structure converts received optical signals into electrical output signals. It offers high sensitivity and fast response, enabling precise detection and conversion of optical signals.

[0021] An FBG sensor array, composed of multiple FBG sensors, enables distributed measurement of various physical quantities. Using a fiber Bragg grating (FBG) structure, each FBG sensor measures optical signals of a specific wavelength and converts them into electrical output signals. This array offers high measurement accuracy and strong anti-interference capabilities, enabling simultaneous measurement of multiple physical quantities.

[0022] Photodetectors detect and convert light signals into electrical output signals. Utilizing the photoelectric effect, they convert received light signals into electrical output signals. These detectors offer high sensitivity and fast response, enabling precise detection and conversion of light signals.

[0023] A logarithmic amplifier performs logarithmic amplification on the input signal, improving signal detection accuracy. It comprises a cascade amplifier, a summing circuit, and a gain amplifier circuit. The gain amplifier circuit amplifies the input signal to generate a first signal; the first amplifier amplifies the input signal to generate a second signal; the second amplifier amplifies the second signal to generate a third signal; and the summing circuit sums the first, second, and third signals. This amplifier offers advantages such as low system error and high signal detection accuracy.

[0024] The analog-to-digital converter digitizes analog signals, converting them into digital output signals. It includes a capacitor array, a comparator, and a logic control circuit. The capacitor array includes a first capacitor array and a second capacitor array. The logic control circuit is configured to apply a preset reference control signal to each capacitor in the first capacitor array and adjust the control signal applied to the second capacitor array during the current comparison based on the results of the previous comparison by the comparator. This converter offers advantages such as high conversion accuracy and good stability.

[0025] The FPGA-compatible algorithm platform processes and analyzes collected digital signals, extracting useful information. Using an FPGA chip as the processing core enables rapid processing and analysis of digital signals. Its fast processing speed and flexible algorithms enable adaptation and optimization for diverse application scenarios.

[0026] The host computer display platform visualizes processed data, facilitating user monitoring and analysis. Using a graphical interface, it displays sensor data and processed results in real time. This platform is easy to use and intuitive, providing a positive user experience.

[0027] The laser output interface of the multi-wavelength tunable laser array light source is connected to the input end of the multi-channel planar optical waveguide branch coupler; the output end of the multi-channel planar optical waveguide branch coupler is first connected to the FBG sensor array, and the MOMES sensor is connected at the end of the FBG sensor array; the return end of the multi-channel planar optical waveguide branch coupler is sequentially connected to a photodetector, a logarithmic amplifier, and an analog-to-digital converter; the digital signal output by the analog-to-digital converter is transmitted to the FPGA-compatible algorithm platform.

[0028] The multi-wavelength tunable laser array light source consists of a matrix multi-wavelength tunable laser array and its hardware control circuit, which is used to generate a broadband swept frequency optical signal with a continuously and rapidly changing wavelength. The signal is output sequentially according to the wavelength from small to large at a fixed frequency step interval and input into the input end of the multi-path planar optical waveguide branch coupler.

[0029] The multi-path planar optical waveguide branch coupler contains M groups of 1×2 splitters. The incident light is first divided into M paths and then output simultaneously by the M 1×2 splitters. One path is first connected to the FBG sensor array, and then connected to the MOMES sensor at the end of the FBG sensor array. Light that meets the FBG reflection conditions is first continuously reflected by the FBG sensor array, forming a continuous FBG reflection spectrum. It enters the MOMES sensor at the end to form a continuous interference spectrum. The other path is output to the photodetector, which receives the continuous FBG string reflection spectrum and the MOMES sensor interference spectrum. The received optical signal is first converted into a current signal, then amplified by a logarithmic amplifier, and then converted from analog to digital signal, and finally processed by an FPGA-compatible algorithm platform.

[0030] The FPGA-compatible algorithm platform searches for peaks and troughs in parallel using a set of data containing reflection and interference spectra. The frequency shift of the peaks is the effect of temperature and strain changes on the FBG sensor array. The Fabry-Perot interference spectrum reflection signal is a set of continuous trough spectra. The center wavelength spacing of the troughs is the free spectrum range, which can be converted into a Fabry-Perot resonant cavity through calculation. The change in the resonant cavity length is further converted into changes in strain and temperature, and finally displayed and processed in real time by the host computer display platform.

[0031] like Figure 2 As shown, the present invention provides a schematic structural diagram of an i×j matrix structured tunable multi-wavelength distributed feedback laser array chip and a 4×6 laser array chip diagram for generating broadband rapid continuous frequency sweeping laser signals.

[0032] The purpose of the i×j matrix multi-wavelength laser array light source is to generate broadband swept-frequency optical signals with continuously and rapidly changing wavelengths, and to output signals in order from small to large wavelengths at a certain fixed frequency step interval. Taking a 4×6 chip as an example, the laser array structure is composed of a 4×6 series-parallel matrix distributed high-density monolithic integrated 24 multi-wavelength DFB unit laser array, which is then merged into an optical waveguide output through a two-stage cascaded 2-in-1 Y-branch active combined waveguide structure, and an SOA is integrated at the front end of the chip to balance the final output swept-frequency optical power. The wavelength of each unit laser is designed with a laser grating wavelength at a wavelength interval of 2nm. ( =1520 nm, =1522 nm, =1524 nm, =1526 nm, =1528 nm, =1530 nm, =1532 nm, =1534 nm, =1536 nm, =1538 nm, =1540 nm, =1542 nm, =1544 nm, =1546 nm, =1548 nm, =1550 nm, =1552 nm, =1554 nm, =1556 nm, =1558 nm, =1560 nm, =1562 nm, =1564 nm, =1566 nm), and then the corresponding unit laser is controlled by the matching laser hardware control circuit according to the wavelength to complete the wavelength scanning ( :1520 nm~1522 nm, :1522~1524 nm, :1524~1526 nm, :1526~1528 nm, :1528~1530 nm, :1530~1532 nm, : 1532~1534 nm, :1534~1536 nm, :1536~1538 nm, :1538~1540 nm, : 1540~1542 nm, :1542~1544 nm, :1544~1546 nm, :1546~1548 nm, :1548~1550nm, :1550~1552 nm, :1552~1554 nm, :1554~ 1556 nm, :1556~1558 nm, :1558~1560 nm, :1560~1562 nm, :1562~1564 nm, :1564~1566 nm, : 1566~1568 nm), covering a 2nm wavelength interval and then switching to the next adjacent wavelength unit laser to continue scanning. By analogy, the output of fast and continuous frequency-sweep optical signals covering a 48nm wavelength range from 1520 to 1568nm can be completed in sequence. Subsequently, in order to facilitate the real-time synchronous acquisition of the swept optical signal by the subsequent detection and acquisition system, the tunable laser signal after linear wavelength output conditioning is continuously scanned, but it outputs a trigger signal at a fixed frequency interval of 5 GHz (approximately equal to 8 pm) to the acquisition system for matching synchronous acquisition.

[0033] like Figure 3 As shown, the present invention provides optical fiber grating (FBG) and micro-opto-electromechanical (MOMES) spectra in the same channel.

[0034] The FPGA-compatible algorithm platform is mainly used for compatible demodulation of MOMES interferometric and FBG reflective sensors. MOMES interferometric sensors and FBG reflective sensors have different spectral characteristics, and the physical parameters used to calculate the sensors are also different. The FBG reflection spectrum mainly depends on the grating period and the effective refractive index neff of the reverse coupling mode. Any physical process that changes these two parameters will cause the grating Bragg wavelength to drift, which is reflected in the movement of peaks and valleys in the spectrum. In this embodiment, 22 gratings with a wavelength matching the array laser are selected and connected in series in a single channel. The design wavelength is =1524.5 nm, =1527.2 nm, =1529.1 nm, =1531.0 nm, =1532.9 nm, =1535.1 nm, =1537.0 nm, =1539.1 nm, =1541.2 nm, =1543.2 nm, =1545.3 nm, =1547.3 nm, =1549.2 nm, =1551.1 nm, =1553.2 nm, =1555.2 nm, =1557.2 nm, =1559.4 nm, =1561.3 nm, =1563.2 nm, =1565.0 nm, =1567.0 nm. This design primarily considers the sensor's limited measurement range, which corresponds to the wavelength shift range. The MOMES sensor is an interferometric sensor. Sweep-frequency light at a specified frequency interval enters the optical fiber. Some of this light is reflected at the first reflective surface, while another portion propagates into the FP cavity and is partially reflected at the second reflective end face. Some of the reflected light then reaches the fiber end face again, interfering with the light reflected from the first end face. When the packaged sensor senses external strain or temperature changes, the effective cavity length of the FP cavity changes, altering the interference spectrum accordingly. The free spectral range is determined by the cavity length. This patent utilizes a sensor with a cavity length of approximately 280 μm. Within a 48 nm bandwidth, 12 troughs can be observed, or 11 free spectral ranges. Theoretically, the frequency spacing of these 11 free spectral ranges is uniform. To further improve accuracy, the average of these 11 free spectral ranges is used in the calculation.

[0035] like Figure 4 As shown, the present invention provides a compatibility algorithm software flow chart.

[0036] The main purpose of the FPGA-compatible algorithm platform is to use the FPGA parallel computing function to realize the demodulation of the peak and the spacing between adjacent troughs. After the host computer sends the start command, the multi-wavelength array laser enters the scanning state and outputs the trigger signal according to the 5Ghz spacing (that is, approximately equal to 40pm). The FPGA chip drives the analog-to-digital conversion chip and waits for the trigger synchronization data of the laser array at the same time. Each trigger received corresponds to an analog-to-digital conversion, that is, the data of the fixed-spacing optical frequency is collected once. The first wavelength output by the laser array is 197225Ghz (1520.050nm). =197220Ghz, =197215Ghz, =197210Ghz,………, =191145Ghz (1568.403nm), and each 1216 acquisitions constitute a frequency sweep cycle, which constitutes a complete spectrum containing the FBG sensor array reflection data and the MOMES sensor interference data. Secondly, before data acquisition, the FPGA opens a FIFO space larger than the channel × 24Mbit. After each acquisition, the data is transmitted to the two FPGA_FIFO resources in real time, and the two FIFO resources containing the spectrum data are released in parallel. The spectrum data of the array FBG sensor will find the maximum point according to the set peak-finding threshold, and the data above the threshold will be found. , record the data of 4 sampling points offset to the left and right of the maximum point as the data required for peak search ( , , , , , , , , ), the other way is to find the minimum point of the data below the threshold according to the set threshold , record the data of 4 sampling points offset to the left and right of the minimum point as the data required for peak search ( , , , , , , , , ), and finally perform binomial fitting on the two channels of data containing several peaks and several trough sampling points in parallel, and the wavelength data obtained is =1524.495 nm, =1527.167 nm, =1529.108 nm, =1531.011 nm, =1532.921 nm, =1535.081 nm, =1537.032 nm, =1539.105 nm, =1541.197 nm, =1543.208 nm, =1545.302 nm, =1547.350 nm, =1549.180 nm, =1551.113nm, =1553.231 nm, =1555.203 nm, =1557.265 nm, =1559.495 nm, =1561.384 nm, =1563.167 nm, =1565.034 nm, =1567.038 nm. The deviation between the measured peak data and the designed grating parameters is caused by the grating force and temperature changes during the grating writing process. The deviation is about 0.1nm. The frequency shift of a set of peak data represents the change of the corresponding FBG sensor array sensor. The continuous trough data is obtained as =1520.051 nm, =1524.201 nm, =1528.379 nm, =1532.575 nm, =1536.792 nm, =1541.041nm, =1545.299 nm, =1549.592 nm, =1553.892nm, =1558.239 nm, =1562.586 nm, =1566.982 nm, the trough spacing is 4.150nm, 4.178nm, 4.196nm, 4.217nm, 4.249nm, 4.258nm, 4.293nm, 4.300nm, 4.347nm, 4.347nm, 4.396nm, and the average is 4.266nm, which is the free spectral range.

[0037] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A MOMES and FBG fusion sensing system based on an adjustable laser array, characterized in that: It includes multi-wavelength tunable laser array light source, multi-channel planar optical waveguide branch coupler, MOMES sensor, FBG sensor array, photodetector, logarithmic amplifier, analog-to-digital converter, FPGA compatible algorithm platform and host computer display platform; The laser output interface of the multi-wavelength tunable laser array light source is connected to the input end of the multi-path planar optical waveguide branch coupler; The output end of the multi-path planar optical waveguide branch coupler is connected to the FBG sensor array, and the end of the FBG sensor array is connected to the MOMES sensor; The return end of the multi-path planar optical waveguide branch coupler is sequentially connected to a photodetector, a logarithmic amplifier and an analog-to-digital converter; The digital signal output by the analog-to-digital converter is transmitted to the FPGA compatible algorithm platform; The multi-wavelength tunable laser array light source generates a frequency-sweeping optical signal with a continuously and rapidly variable wavelength, and the signal with a fixed step frequency interval is input into the input end of the multi-path planar optical waveguide branch coupler; The multi-path planar optical waveguide splitting coupler has M groups of 1×2 splitters inside. The incident light is first split into M paths and then simultaneously output by the M 1×2 splitters. One of the splitter outputs is connected to the FBG sensor array, and the end of the FBG sensor array is connected to the MOMES sensor. Light that meets the FBG reflection conditions is first continuously reflected by the FBG sensor array, forming a continuous FBG reflection spectrum, and finally enters the MOMES sensor at the end to form a continuous interference spectrum. The other output of the splitter is connected to a photodetector, which receives the continuous FBG reflectance spectrum and the MOMES sensor interference spectrum. The photodetector first converts the received optical signal into an electrical signal, then amplifies the electrical signal through a logarithmic amplifier, and then performs analog-to-digital conversion on the amplified electrical signal through an analog-to-digital converter, and finally outputs it to the FPGA-compatible algorithm platform. The FPGA-compatible algorithm platform processes data containing reflection and interference spectra in parallel to identify peaks and troughs. The frequency shift of the peaks reflects the influence of temperature and strain changes on the FBG sensor array. The reflected signal of the Fabry-Perot interference spectrum appears as a continuous trough spectrum. The spacing between the center wavelengths of the trough spectrum represents the free spectral range. The center wavelength spacing is converted into a change in the cavity length of the Fabry-Perot resonant cavity, and then into changes in strain and temperature. Finally, the host computer display platform displays the changes in strain and temperature in real time.

2. The MOMES and FBG fusion sensing system according to claim 1, wherein: The multi-wavelength tunable laser array light source consists of a matrix multi-wavelength tunable laser array and its hardware control circuit, which is used to generate a broadband swept frequency optical signal with a continuously and rapidly changing wavelength, and output the signal in sequence from small to large wavelength according to a fixed frequency step interval.

3. The MOMES and FBG fusion sensing system according to claim 2, wherein: The matrix-type multi-wavelength tunable laser array is composed of i×j series-parallel matrix-distributed monolithically integrated multiple multi-wavelength distributed feedback unit laser arrays, which are combined into an optical waveguide output through a multi-stage cascaded 2-in-1 Y-branch active combiner waveguide structure, and a semiconductor optical amplifier is integrated at the front end of the optical waveguide to balance the power of the output swept frequency optical signal.

4. The MOMES and FBG fusion sensing system according to claim 3, wherein: The wavelength of each unit laser is set according to the preset wavelength interval to set the laser grating wavelength. The laser hardware control circuit controls the corresponding unit laser according to the wavelength size to complete the wavelength scanning to cover the wavelength interval at a fixed frequency step interval, and then switches to the next unit laser with an adjacent wavelength in sequence, and so on to complete the output of fast and continuous frequency-scanning optical signals covering a broadband wavelength range.

5. The MOMES and FBG fusion sensing system according to claim 1, wherein: The FPGA compatible algorithm platform is used to be compatible with MOMES interferometric sensors and FBG reflective sensors; The reflection spectrum of the FBG reflective sensor is determined by the grating characteristics, and grating arrays with different reflection wavelengths are prepared according to different grating periods and refractive indices; The MOMES interference sensor forms a continuous interference spectrum according to the change of the interference cavity length.

6. The MOMES and FBG fusion sensing system according to claim 5, wherein: The FPGA-compatible algorithm platform utilizes the FPGA parallel computing function to realize the demodulation steps of the peak and the distance between adjacent troughs, including: The FPGA-compatible algorithm platform drives the analog-to-digital conversion chip to continuously collect data at preset optical frequencies. One frequency sweep cycle forms a spectrum containing the FBG sensor array reflection data and the MOMES sensor interference data. After each acquisition is completed, the data is transmitted to two FPGA_FIFO resources in real time. The two FIFO resources containing spectral data are released in parallel. One of the FIFO resources searches for the maximum point in the data above the first threshold according to the first threshold. The 9 sampling values ​​offset by 4 sampling points to the left and right of the maximum point are recorded as the data required for peak search. The other one searches for the minimum point in the data below the second threshold according to the second threshold. The 9 sampling values ​​offset by 4 sampling points to the left and right of the minimum point are recorded as the data required for valley search. Binomial fitting is performed on two data sets containing several peak and trough sampling points to obtain continuous peak data and continuous trough data. The frequency shift of the peak data represents the change of the corresponding FBG sensor array, and the data of the distance between consecutive adjacent troughs is the change of the interference cavity length.

7. The MOMES and FBG fusion sensing system according to claim 1, wherein: The MOMES sensor and the FBG sensor array simultaneously utilize the peak and trough data of the spectrum to achieve synchronous demodulation of the FBG sensor array and the MOMES sensor in the same channel.

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