Fiber optic modulator based on a swept source and a microwave photon

Abstract

The application discloses a F-P demodulation method, system and medium based on a swept light source and a microwave photon, and the method comprises the following steps: 1) a swept light source outputs an optical signal, and a microwave is generated by a vector network analyzer; 2) a circulator transmits the optical signal to an F-P sensor, the F-P sensor generates an interference spectrum, and the circulator outputs the interference spectrum to an electro-optic modulator; 3) the electro-optic modulator receives the interference spectrum and the microwave, and intensity modulates the interference spectrum and the microwave to obtain a modulated optical signal; 4) the modulated optical signal is transmitted to a photoelectric detector, the photoelectric detector converts the optical signal into an electrical signal, and the electrical signal is input into the vector network analyzer; and 5) the vector network analyzer processes the collected signal to calculate an F-P cavity length L. The system comprises a swept light source, an F-P sensor, a circulator, a vector network analyzer, an electro-optic modulator and a photoelectric detector; and the application greatly improves the sensitivity of the F-P demodulation system.

Description

Fabry-Perot demodulation method, system, and medium based on swept frequency light source and microwave photons. Technical Field

[0001] This invention relates to the field of fiber optic sensing, specifically to a Fabry-Perot demodulation method, system, and medium based on a swept-frequency light source and microwave photons. Background Technology

[0002] Temperature, stress, and pressure are crucial parameters in the testing and application analysis of large machinery. Accurate measurement of these parameters is vital in many fields, including aerospace, defense, and industry. For example, in the development of aero-engines, it is necessary to test the temperature and pressure of airflow in the inlet and interstage components. Temperature and stress testing are also involved in weapon research, including missile exhaust jets, ammunition explosions, and the inner and outer walls of gun barrels. These applications are characterized by high temperatures, large temperature ranges, harsh measurement environments, and difficulty in repeatability, placing extremely high demands on measurement accuracy and presenting significant challenges. Currently used electrical testing methods, such as thermocouples and hot wires for temperature measurement, resistance strain gauges for strain measurement, and piezoelectric methods for pressure measurement, have shortcomings in terms of interference resistance and probe size, making them insufficient for the high-precision measurement requirements under harsh conditions. Fiber optic sensing technology, on the other hand, offers advantages such as interference resistance, small size, high precision, and high reliability, making it suitable for temperature measurement needs under harsh environmental conditions. Fiber optic Fabry-Perot temperature measurement technology has been widely used in conventional temperature, stress, and pressure measurements. However, in existing applications, the sensitivity of the measurement system itself is generally limited, and targeted improvements are necessary to meet the high-precision testing requirements of the aforementioned special application environments.

[0003] A classic Fabry-Perot temperature measurement system based on a broadband light source and a spectrometer, as shown in Figure 1, involves a broadband light source emitting a time-continuous optical signal that travels through a circulator to the Fabry-Perot sensor. After sensing the measured physical quantity, the Fabry-Perot sensor returns the optical signal carrying the measurement information, which is then collected by the spectrometer. This system can obtain all spectral information of the Fabry-Perot sensor within a certain wavelength band, resulting in high demodulation accuracy. However, the high cost of spectrometers increases the system cost. Furthermore, the slow speed of spectrometers limits the system's sensing and demodulation rate.

[0004] Another commonly used method is the Fabry-Perot demodulation system based on a swept-frequency light source, as shown in Figure 2. The swept-frequency light source emits signals of different optical frequencies in chronological order, which then pass through a circulator and reach the Fabry-Perot sensor. After sensing the measured physical quantity, the Fabry-Perot sensor returns the optical signal carrying the measurement information and is converted into an electrical signal by a photodetector. The electrical signal is then acquired by the data processing module. This system can also obtain the complete spectral information of the Fabry-Perot sensor within a certain wavelength band, achieving high demodulation accuracy. Compared to demodulation systems based on broadband light sources and spectrometers, the swept-frequency light source-based demodulation system significantly improves the demodulation rate while maintaining high demodulation accuracy. The drawback of the above-mentioned general Fabry-Perot demodulation systems is that, limited by the fiber optic sensing principle, the sensing sensitivity has a certain upper limit. Summary of the Invention

[0005] The purpose of this invention is to propose a Fabry-Perot demodulation system based on a swept-frequency light source and microwave photons, which addresses the shortcomings of existing Fabry-Perot demodulation systems with low sensitivity.

[0006] The technical solution adopted to achieve the purpose of this invention is as follows: a Fabry-Perot demodulation method based on a swept-frequency light source and microwave photons, comprising the following steps:

[0007] 1) The sweep frequency light source outputs an optical signal, and the vector network analyzer generates microwaves.

[0008] 2) The circulator transmits the optical signal output from the sweep frequency light source to the Fabry sensor.

[0009] After receiving the optical signal, the Fabry sensor generates an interference spectrum and outputs the interference spectrum to the electro-optic modulator through a circulator.

[0010] 3) The electro-optic modulator receives the interference spectrum output by the circulator and the microwave generated by the vector network analyzer, and modulates the intensity of the interference spectrum and the microwave to obtain the modulated optical signal.

[0011] 4) The electro-optic modulator transmits the modulated optical signal to the photodetector, which converts the received optical signal into an electrical signal and inputs it into the vector network analyzer.

[0012] 5) The vector network analyzer processes the acquired signals and calculates the length L of the Fabry cavity.

[0013] Furthermore, the frequency-sweeping light source outputs optical signals of different frequencies in chronological order. The optical signals output by the frequency-sweeping light source are shown below:

[0014] u[t]=u1+kt,t∈[t1,t2,…,t N (1)

[0015] In the formula, t is time, u[t] is the optical frequency at time t, u1 is the initial optical frequency, and N is the number of output optical signals of the frequency sweep light source in one cycle.

[0016] The optical frequency output slope k of the swept frequency light source is shown below:

[0017]

[0018] In the formula, u tN For t N The optical frequency at a given moment, u t1 Let t1 be the optical frequency at time t1.

[0019] Furthermore, the interference signal I1(u) generated by the Fabry-Perot sensor in the optical frequency domain is shown below:

[0020]

[0021] In the formula, u is the optical frequency, L is the Fabry-Perot cavity length, and c is the speed of light in a vacuum.

[0022] The interference signal I2(t) generated in the time domain by the Fabry-Perot sensor is shown below:

[0023]

[0024] In the formula, t is time, u1 is the initial optical frequency, and k is the optical frequency output slope of the swept light source.

[0025] Furthermore, the time-domain frequency f of the interference signal from the Fabry-Perot sensor FP As shown below:

[0026]

[0027] Furthermore, the transfer function H of the electro-optic modulator EOM (Ω) is shown below:

[0028] H EOM (Ω)=1+Mcos(Ωt)=1+M1e -jΩt +M2e jΩt (6)

[0029] In the formula, t is time, Ω is the microwave frequency at time t, and M, M1, and M2 are all modulation depths.

[0030] Furthermore, the optical signal I3(Ω) received by the photodetector is as follows:

[0031]

[0032] In the formula, t is time, N is the number of output optical signals of the swept frequency light source in one cycle, Ω is the microwave frequency at time t, and I2(t) is the interference signal generated by the Fabry-Perot sensor in the time domain.

[0033] H EOM (Ω) is the transfer function of the electro-optic modulator.

[0034] Furthermore, when the time-domain frequency f of the Fabry sensor interference signal... FP When the frequency Ω is equal to the microwave frequency, the optical signal I3(Ω) received by the photodetector reaches its maximum.

[0035] Further, in step 5), the vector network analyzer processes the acquired signal, and when the time-domain frequency f of the Fabry sensor interference signal... FP When the microwave frequency Ω is equal to the Fabry-Perot cavity length L, the length L can be calculated using formula (8).

[0036] The length L of the Fabry cavity is shown below:

[0037]

[0038] In the formula, c is the speed of light in a vacuum, and k is the output slope of the sweep frequency light source.

[0039] A Fabry-Perot demodulation system for the above-mentioned Fabry-Perot demodulation method based on a swept frequency light source and microwave photons includes: a swept frequency light source, a Fabry-Perot sensor, a circulator, a vector network analyzer, an electro-optic modulator, and a photodetector.

[0040] The frequency-sweeping light source is used to output optical signals.

[0041] The Fabry-Perot sensor is used to generate interference spectra.

[0042] The circulator is used for unidirectional signal transmission.

[0043] The vector network analyzer is used to generate microwaves and analyze the acquired signals.

[0044] The electro-optic modulator modulates the intensity of the interference spectrum and microwaves.

[0045] The photodetector converts the received optical signal into an electrical signal.

[0046] A computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of the above-described method.

[0047] The technical effectiveness of this invention is undeniable. This invention proposes a Fabry-Perot demodulation system based on a swept-frequency light source and microwave photons. This invention demodulates Fabry-Perot sensing information by loading microwave signals of different frequencies onto the time-domain swept-frequency interference spectrum of a Fabry-Perot sensor and constructing a correlation function between the microwave frequency and the Fabry-Perot interference frequency.

[0048] This invention is the first to combine a swept-frequency light source with a microwave photonics system. The swept-frequency light source has the function of one-to-one mapping between the time domain and the frequency domain, and can map the FP interferometric optical frequency in the optical frequency domain to the time domain, and then modulate and demodulate it with a microwave signal in the time domain.

[0049] The time-domain Fabry-Perot interference frequency of this invention is k times that of the traditional frequency-domain interference frequency. When the cavity length L changes, the resulting change in interference frequency is also k times. Therefore, the sensitivity of the system proposed in this invention is k times higher than that of existing technologies. k is the sweep output slope of the sweep light source, which is related to the optical frequency range and sweep period of the sweep light source. Increasing the rate of the sweep light source is beneficial to improving the system's sensitivity. Attached Figure Description

[0050] Figure 1 shows an existing Fabry-Perot demodulation system based on a broadband light source and spectrometer;

[0051] Figure 2 shows an existing Fabry-Perot demodulation system based on a swept-frequency light source;

[0052] Figure 3 shows the FP demodulation system based on a swept frequency light source and microwave photons according to the present invention;

[0053] Figure 4 shows the signals acquired by the vector network analyzer of this invention. Detailed Implementation

[0054] The present invention will be further described below with reference to embodiments, but it should not be construed that the scope of the present invention is limited to the following embodiments. Various substitutions and modifications made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention should be included within the scope of protection of the present invention.

[0055] Example 1:

[0056] Referring to Figures 3 and 4, the Fabry-Perot demodulation method based on a swept-frequency light source and microwave photons includes the following steps:

[0057] 1) The sweep frequency light source outputs an optical signal, and the vector network analyzer generates microwaves.

[0058] 2) The circulator transmits the optical signal output from the sweep frequency light source to the Fabry sensor.

[0059] After receiving the optical signal, the Fabry sensor generates an interference spectrum and outputs the interference spectrum to the electro-optic modulator through a circulator.

[0060] 3) The electro-optic modulator receives the interference spectrum output by the circulator and the microwave generated by the vector network analyzer, and modulates the intensity of the interference spectrum and the microwave to obtain the modulated optical signal.

[0061] 4) The electro-optic modulator transmits the modulated optical signal to the photodetector, which converts the received optical signal into an electrical signal and inputs it into the vector network analyzer.

[0062] 5) The vector network analyzer processes the acquired signals and calculates the length L of the Fabry cavity.

[0063] The frequency-sweeping light source outputs optical signals of different frequencies in chronological order. The frequency-sweeping light source outputs optical signals with equal time intervals and equal optical frequency intervals, using time as the independent variable. The optical signals output by the frequency-sweeping light source are shown below:

[0064] u[t]=u1+kt,t∈[t1,t2,…,t N (1)

[0065] In the formula, t is time, u[t] is the optical frequency at time t, u1 is the initial optical frequency, and N is the number of output optical signals of the frequency sweep light source in one cycle.

[0066] The optical frequency output slope k of the swept frequency light source is shown below:

[0067]

[0068] In the formula, u tN For t N The optical frequency at a given moment, u t1 Let t1 be the optical frequency at time t1.

[0069] The interference signal I1(u) generated by the Fabry-Perot sensor in the optical frequency domain is shown below:

[0070]

[0071] In the formula, u is the optical frequency, L is the Fabry-Perot cavity length, and c is the speed of light in a vacuum.

[0072] The interference signal I2(t) generated in the time domain by the Fabry-Perot sensor is shown below:

[0073]

[0074] In the formula, t is time, u1 is the initial optical frequency, and k is the optical frequency output slope of the swept light source.

[0075] The time-domain frequency f of the interference signal from the Fapper sensor FPAs shown below:

[0076]

[0077] The transfer function H of the electro-optic modulator EOM (Ω) is shown below:

[0078] H EOM (Ω)=1+Mcos(Ωt)=1+M1e -jΩt +M2e jΩt (6)

[0079] In the formula, t is time, Ω is the microwave frequency at time t, and M, M1, and M2 are all modulation depths.

[0080] The optical signal I3(Ω) received by the photodetector is shown below:

[0081]

[0082] In the formula, t is time, N is the number of output optical signals of the swept frequency light source in one cycle, Ω is the microwave frequency at time t, and I2(t) is the interference signal generated by the Fabry-Perot sensor in the time domain.

[0083] H EOM (Ω) is the transfer function of the electro-optic modulator.

[0084] When the time-domain frequency f of the interference signal from the Fapper sensor FP When the frequency Ω is equal to the microwave frequency, the optical signal I3(Ω0) received by the photodetector reaches its maximum.

[0085] In step 5), the vector network analyzer processes the acquired signal, and when the time-domain frequency f of the Fabry sensor interference signal... FP When the microwave frequency Ω is equal to the Fabry-Perot cavity length L, the length L can be calculated using formula (8).

[0086] The length L of the Fabry cavity is shown below:

[0087]

[0088] In the formula, c is the speed of light in a vacuum, and k is the output slope of the sweep frequency light source.

[0089] A Fabry-Perot demodulation system for the above-mentioned Fabry-Perot demodulation method based on a swept frequency light source and microwave photons includes: a swept frequency light source, a Fabry-Perot sensor, a circulator, a vector network analyzer, an electro-optic modulator, and a photodetector.

[0090] The frequency-sweeping light source is used to output optical signals. It outputs optical signals of different frequencies in chronological order, thus possessing a time-frequency mapping function. The sweep rate can reach tens of kHz.

[0091] The Fabry-Perot sensor is used to generate interference spectra. The Fabry-Perot sensor senses physical quantities and generates interference signals.

[0092] The circulator is used for unidirectional signal transmission.

[0093] The vector network analyzer is used to generate microwaves and analyze the acquired signals.

[0094] The electro-optic modulator modulates the intensity of the interference spectrum and the microwave. The electro-optic modulator loads the microwave electrical signal transmitted from the vector network onto the optical signal.

[0095] The photodetector converts the received optical signal into an electrical signal.

[0096] A computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of the above-described method.

[0097] Example 2:

[0098] Referring to Figures 3 and 4, the Fabry-Perot demodulation method based on a swept-frequency light source and microwave photons includes the following steps:

[0099] 1) The sweep frequency light source outputs an optical signal, and the vector network analyzer generates microwaves.

[0100] 2) The circulator transmits the optical signal output from the sweep frequency light source to the Fabry sensor.

[0101] After receiving the optical signal, the Fabry sensor generates an interference spectrum and outputs the interference spectrum to the electro-optic modulator through a circulator.

[0102] 3) The electro-optic modulator receives the interference spectrum output by the circulator and the microwave generated by the vector network analyzer, and modulates the intensity of the interference spectrum and the microwave to obtain the modulated optical signal.

[0103] 4) The electro-optic modulator transmits the modulated optical signal to the photodetector, which converts the received optical signal into an electrical signal and inputs it into the vector network analyzer.

[0104] 5) The vector network analyzer processes the acquired signals and calculates the length L of the Fabry cavity.

[0105] Example 3:

[0106] The Fabry-Perot demodulation method based on a swept-frequency light source and microwave photons, with its main steps described in Example 2, involves the swept-frequency light source outputting optical signals of different frequencies in chronological order. The swept-frequency light source outputs optical signals with equal time intervals and equal optical frequency intervals, using time as the independent variable. The optical signals output by the swept-frequency light source are shown below:

[0107] u[t]=u1+kt,t∈[t1,t2,…,t N (1)

[0108] In the formula, t is time, u[t] is the optical frequency at time t, u1 is the initial optical frequency, and N is the number of output optical signals of the frequency sweep light source in one cycle.

[0109] The optical frequency output slope k of the swept frequency light source is shown below:

[0110]

[0111] In the formula, u tN For t N The optical frequency at a given moment, u t1 Let t1 be the optical frequency at time t1.

[0112] Example 4:

[0113] The Fabry-Perot demodulation method based on a swept-frequency light source and microwave photons mainly follows the steps described in Example 2. The interference signal I1(u) generated by the Fabry-Perot sensor in the optical frequency domain is shown below:

[0114]

[0115] In the formula, u is the optical frequency, L is the Fabry-Perot cavity length, and c is the speed of light in a vacuum.

[0116] The interference signal I2(t) generated in the time domain by the Fabry-Perot sensor is shown below:

[0117]

[0118] In the formula, t is time, u1 is the initial optical frequency, and k is the optical frequency output slope of the swept light source.

[0119] Example 5:

[0120] The Fabry-Perot demodulation method based on a swept-frequency light source and microwave photons, with its main steps described in Example 2, wherein the time-domain frequency f of the Fabry-Perot sensor interference signal is... FP As shown below:

[0121]

[0122] Example 6:

[0123] The Fabry-Perot demodulation method based on a swept-frequency light source and microwave photons, with its main steps described in Example 2, wherein the transfer function H of the electro-optic modulator is... EOM (Ω) is shown below:

[0124] H EOM (Ω)=1+Mcos(Ωt)=1+M1e -jΩt +M2e jΩt (6)

[0125] In the formula, t is time, Ω is the microwave frequency at time t, and M, M1, and M2 are all modulation depths.

[0126] Example 7:

[0127] The Fabry-Perot demodulation method based on a swept-frequency light source and microwave photons mainly follows the steps described in Example 2. The optical signal I3(Ω) received by the photodetector is shown below:

[0128]

[0129] In the formula, t is time, N is the number of output optical signals of the swept frequency light source in one cycle, Ω is the microwave frequency at time t, and I2(t) is the interference signal generated by the Fabry-Perot sensor in the time domain.

[0130] H EOM (Ω) is the transfer function of the electro-optic modulator.

[0131] Example 8:

[0132] The Fabry-Perot demodulation method based on a swept-frequency light source and microwave photons, with its main steps described in Example 7, involves the following steps: when the time-domain frequency f of the Fabry-Perot sensor interference signal... FP When the frequency Ω is equal to the microwave frequency, the optical signal I3(Ω) received by the photodetector reaches its maximum.

[0133] Example 9:

[0134] The Fabry-Perot demodulation method based on a swept-frequency light source and microwave photons, with its main steps described in Example 2, includes step 5), where the vector network analyzer processes the acquired signal. When the time-domain frequency f of the Fabry-Perot sensor interference signal... FP When the microwave frequency Ω is equal to the Fabry-Perot cavity length L, the length L can be calculated using formula (8).

[0135] The length L of the Fabry cavity is shown below:

[0136]

[0137] In the formula, c is the speed of light in a vacuum, and k is the output slope of the sweep frequency light source.

[0138] Example 10:

[0139] A Fabry-Perot demodulation system for use with the Fabry-Perot demodulation method based on swept frequency light source and microwave photons described in Examples 2-9 includes: a swept frequency light source, a Fabry-Perot sensor, a circulator, a vector network analyzer, an electro-optic modulator, and a photodetector.

[0140] The frequency-sweeping light source is used to output optical signals. It outputs optical signals of different frequencies in chronological order, thus possessing a time-frequency mapping function. The sweep rate can reach tens of kHz.

[0141] The Fabry-Perot sensor is used to generate interference spectra. The Fabry-Perot sensor senses physical quantities and generates interference signals.

[0142] The circulator is used for unidirectional signal transmission.

[0143] The vector network analyzer is used to generate microwaves and analyze the acquired signals.

[0144] The electro-optic modulator modulates the intensity of the interference spectrum and the microwave. The electro-optic modulator loads the microwave electrical signal transmitted from the vector network onto the optical signal.

[0145] The photodetector converts the received optical signal into an electrical signal.

[0146] Example 11:

[0147] A computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of the methods described in Examples 2-9.

[0148] Example 12:

[0149] Referring to Figures 3 and 4, the Fabry-Perot demodulation system based on a swept-frequency light source and microwave photons is shown in Figure 3. The light output from the swept-frequency light source generates an interference spectrum at the Fabry-Perot sensor. The interference spectrum and the microwave emitted by the vector network analyzer are intensity modulated at an electro-optic modulator. After the interference spectrum and microwave meet and are modulated, they reach the photodetector, which converts the light into an electrical signal, which is then collected and analyzed by the vector network analyzer.

[0150] Frequency-sweeping light source: It outputs optical signals of different frequencies in chronological order, thus possessing time-frequency mapping capabilities. The frequency sweep rate can reach tens of kHz.

[0151] Fabry-Perot sensor: Sensing physical quantities and generating interference signals.

[0152] Electro-optic modulator: Loads the microwave electrical signal transmitted from the vector network onto the optical signal.

[0153] Photodetector: Converts electrical signals into optical signals.

[0154] Vector network analyzer: It outputs microwave signals of different frequencies while simultaneously acquiring and analyzing electrical signals transmitted from photodetectors.

[0155] A swept-frequency light source outputs an optical signal with equal time intervals and equal optical frequency intervals, using time as the independent variable. Therefore, its optical signal can be written as:

[0156] u[t]=u1+kt,t∈[t1,t2,…,t N (1)

[0157]

[0158] Where u is the optical frequency, t is the time, k is the optical frequency output slope of the sweep frequency source, and N is the number of output optical signals of the sweep frequency source in one cycle.

[0159] When the optical signal from the swept frequency source passes through the Fabryer, the interference signal in the optical frequency domain is:

[0160]

[0161] The time-domain interference signal is:

[0162]

[0163] The transfer function of the electro-optic modulator is:

[0164] H EOM (Ω)=1+Mcos(Ωt)=1+M1e -jΩt +M2e jΩt (5)

[0165] Where Ω is the microwave frequency at this moment, M is the modulation depth, and τ is the duration of a microwave signal.

[0166] Combining formulas (4) and (5), the signal detected by the photodetector can be obtained as follows:

[0167]

[0168] From formula (4), the time-domain frequency of the FP interference signal is:

[0169]

[0170] From formula (6), it can be seen that when f FP When I3(Ω) equals Ω, I3(Ω) has a maximum value, as shown in Figure 2. Therefore, when I3(Ω) has a maximum value, it can be considered that:

[0171] f FP =Ω (8)

[0172] From formulas (7) and (8), the length of the Fabry cavity can be expressed as:

[0173]

[0174] This is the first time that a swept-frequency light source and a microwave photonics system have been combined. The swept-frequency light source has the function of one-to-one mapping between the time domain and the frequency domain, and can map the FP interferometric optical frequency in the optical frequency domain to the time domain, and then modulate and demodulate it with a microwave signal in the time domain.

[0175] Secondly, the time-frequency mapping function of the swept frequency light source can improve the system demodulation sensitivity by a factor of k.

[0176] From formula (3), the interference frequency of the Fabry-Perot interference spectrum of the traditional fiber optic Fabry-Perot demodulation system in the frequency domain is:

[0177]

[0178] However, based on the Fabry-Perot demodulation system using a swept-frequency light source and microwave photons, the Fabry-Perot interference spectrum in the time domain, according to formula (4), has the following interference frequency:

[0179]

[0180] Comparing formulas (10) and (11), the time-domain Fabry-Perot interference frequency of this invention is k times that of the traditional frequency-domain interference frequency. When the cavity length L changes, the resulting change in interference frequency is also k times. Therefore, the sensitivity is improved by k times.

[0181] As shown in formula (2), k is the sweep output slope of the sweep light source, which is related to the optical frequency range and sweep period of the sweep light source. Increasing the rate of the sweep light source is beneficial to improving the sensitivity of the system.

Claims

1. A Fabry-Perot demodulation method based on a swept-frequency light source and microwave photons, characterized in that, Includes the following steps: 1) The sweep frequency light source outputs an optical signal, and the vector network analyzer generates microwaves; 2) The circulator transmits the optical signal output from the swept frequency light source to the Fabry-Perot sensor; the Fabry-Perot sensor receives the optical signal, generates an interference spectrum, and outputs the interference spectrum to the electro-optic modulator through the circulator; the interference signal generated by the Fabry-Perot sensor in the optical frequency domain As shown below: (1) In the formula, u is the optical frequency, L is the Fabry-Perot cavity length, and c is the speed of light in a vacuum; the interference signal generated by the Fabry-Perot sensor in the time domain As shown below: (2) In the formula, t is time, u1 is the initial optical frequency, and k is the optical frequency output slope of the swept frequency source; the time domain frequency of the interference signal of the Fabry sensor. As shown below: (3) The electro-optic modulator receives the interference spectrum output by the circulator and the microwave generated by the vector network analyzer, and modulates the intensity of the interference spectrum and the microwave to obtain the modulated optical signal; The transfer function of the electro-optic modulator As shown below: (4) In the formula, t is time. t is the microwave frequency, M, M1, and M2 are all modulation depths; 4) The electro-optic modulator transmits the modulated optical signal to the photodetector, which converts the received optical signal into an electrical signal and inputs it into the vector network analyzer. The photodetector receives the optical signal As shown below: (5) In the formula, t is the time, and N is the number of output optical signals of the swept frequency light source in one cycle. Let be the microwave frequency at time t. It is the interference signal generated in the time domain by the Fabry sensor. It is the transfer function of the electro-optic modulator; when the time-domain frequency of the Fabry sensor interference signal... and microwave frequency When they are equal, the optical signal received by the photodetector 5) The vector network analyzer processes the acquired signal to calculate the Fabry-Perot cavity length L; the vector network analyzer processes the acquired signal, and when the time domain frequency of the Fabry-Perot sensor interference signal reaches its maximum; and microwave frequency When they are equal, the Fabry-Perot cavity length L is calculated using formula (6); the Fabry-Perot cavity length L is shown below: (6) In the formula, c is the speed of light in a vacuum and k is the output slope of the sweep frequency light source.

2. The Fabry-Perot demodulation method based on a swept-frequency light source and microwave photons according to claim 1, characterized in that, The frequency-sweeping light source outputs optical signals of different frequencies in chronological order; the optical signals output by the frequency-sweeping light source are shown below: (7) In the formula, t is time, u U is the optical frequency at time t, u1 is the initial optical frequency, and N is the number of output optical signals of the frequency-sweeping light source in one cycle; the output optical frequency slope k of the frequency-sweeping light source is shown below: In formula (8), for The light frequency at any given moment 。 3. A Fabry-Perot demodulation system applied to the Fabry-Perot demodulation method based on a swept-frequency light source and microwave photons as described in any one of claims 1-2, characterized in that, include: The system comprises a swept frequency light source, a Fabry-Perot sensor, a circulator, a vector network analyzer, an electro-optic modulator, and a photodetector; the swept frequency light source is used to output optical signals; the Fabry-Perot sensor is used to generate interference spectra; the circulator is used to transmit signals unidirectionally; and the vector network analyzer is used to generate microwaves and analyze the acquired signals. The electro-optic modulator modulates the intensity of the interference spectrum and microwaves; The photodetector converts the received optical signal into an electrical signal.

4. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the steps of the method described in any one of claims 1-2.

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