A fiber optic seismic gyroscope based on autocorrelation quantum weak measurement

Abstract

This invention provides a fiber optic seismic gyroscope based on autocorrelation quantum weak measurement, comprising a gyroscope carrier and an optical module. The optical module includes: a pre-selection polarization module for adjusting the quantum state of photons; a beam splitter for splitting the adjusted photons into two beams to achieve time-autocorrelation quantum weak measurement; a weak coupling module for achieving weak coupling in quantum weak measurement; a post-selection polarization module for a second polarizer for post-selection in quantum measurement and a third polarizer for post-selection in standard quantum weak measurement; and a data receiving and processing module, including a programmable gate array for analyzing and processing measurement data to obtain gyroscope parameters. This invention couples the rotational angular velocity information to the phase difference of polarized light through an angular velocity sensing fiber loop to obtain the autocorrelation coefficient of the autocorrelation quantum weak measurement, and then obtains the relationship between the autocorrelation coefficient and the rotational angular velocity, exhibiting higher measurement accuracy and robustness under strong environmental noise.

Description

Technical Field

[0001] This invention relates to the field of seismic wave measurement technology in high-noise environments, and specifically to a fiber optic seismic gyroscope based on autocorrelation quantum weak measurement. Background Technology

[0002] Extracting useful observable signals from environmental noise has always been a key focus and challenge in geophysical observation. Accurate measurement of the planar and rotational motions of the Earth's surface is of great significance for seismic tectonics, earthquake monitoring, the development of seismic instruments, and research in earthquake engineering.

[0003] In recent years, in the study of rotational seismology, the measurement of angular velocity has a lower signal-to-noise ratio than the traditional measurement of translational velocity, and requires higher measurement accuracy and is more difficult to measure.

[0004] Traditional fiber optic gyroscopes have been widely used in fields such as earthquake monitoring, aviation and navigation, and self-aligning strategic missiles. Although fiber optic gyroscopes have the advantages of high measurement sensitivity, strong anti-electromagnetic interference capability, and wide dynamic range, their measurement sensitivity and stability (zero drift) are still difficult to achieve the measurement accuracy required for rotating geosciences research.

[0005] In low-frequency seismic wave detection, large ring lasers (e.g., UG-2 lasers) and cold atom interferometers are used due to their higher sensitivity and measurement frequency. However, the maintenance of large ring lasers and cold atom interferometers requires a large amount of financial investment; and the measurement accuracy of cold atom interferometers is ultimately limited by the fluctuations in atomic trajectory.

[0006] Fiber optic gyroscopes use photons as their working medium, and photons have low energy. In rotational seismology research, a sufficiently large equivalent optical path area is required to ensure adequate measurement sensitivity. Compared to traditional quantum weak measurement techniques, autocorrelation quantum weak measurement techniques exhibit better robustness in low signal-to-noise ratio environments and can maintain the ability to amplify weak values ​​in quantum weak measurements.

[0007] Therefore, improving traditional fiber optic gyroscopes based on the autocorrelation quantum weak measurement principle to achieve low signal-to-noise ratio and high sensitivity measurement of rotational angular velocity is an important research topic in earthquake engineering. Summary of the Invention

[0008] This invention provides a fiber optic seismic gyroscope based on autocorrelation quantum weak measurement to solve the technical problems of low robustness and low sensitivity of current fiber optic gyroscopes in strong noise environments.

[0009] To address the aforementioned problems, this invention provides a fiber optic seismic gyroscope based on autocorrelation quantum weak measurement, comprising a gyroscope carrier for emitting photon signals, and an optical module for measuring the rotational angular velocity of the gyroscope carrier. The optical module includes:

[0010] A pre-selective polarization module is used to adjust the photon to its quantum state;

[0011] A beam splitter is used to split the photons after adjustment by the pre-selective polarization module into two beams to achieve time-autocorrelated quantum weak measurement.

[0012] The weak coupling module is used to achieve weak coupling of incoming polarized light for quantum weak measurement;

[0013] The post-selection polarization module includes a second polarizer and a third polarizer, wherein the second polarizer is used for post-selection in quantum measurement and the third polarizer is used for post-selection in standard quantum weak measurement.

[0014] The data receiving and processing module includes a programmable gate array for generating control signals. The programmable gate array analyzes and processes the measurement data to obtain the autocorrelation coefficient Θ(t), thereby obtaining the rotational angular velocity Ω of the gyroscope.

[0015] The functional relationship between the autocorrelation coefficient Θ(t) and the rotational angular velocity Ω of the gyroscope is expressed as follows:

[0016]

[0017] Where: β represents the angle between the polarization direction of the synthesized polarized beam after passing through the second polarizer (141) and the horizontal direction, c represents the speed of light in vacuum, N represents the number of turns of the fiber ring, S represents the area of ​​the fiber ring, and ω represents the width of the time-domain Gaussian pointer.

[0018] Furthermore, the pre-selective polarization module includes a laser, an electro-optic modulator, and a first polarizer. The laser beam emitted by the laser is converted into a Gaussian waveform in time after passing through the electro-optic modulator, and then adjusted into the quantum state of photons by the first polarizer.

[0019] Furthermore, the weakly coupled module includes a polarization beam splitter, a first self-collimating lens, an angular velocity sensing fiber ring, and a second self-collimating lens. The polarization beam splitter splits linearly polarized light into vertically polarized light and horizontally polarized light. The first and second self-collimating lenses are used to connect the free light path to the angular velocity sensing fiber ring.

[0020] The vertically polarized light propagates clockwise through the first autocollimating lens, the angular velocity sensing fiber optic loop, and the second autocollimating lens in sequence.

[0021] The horizontally polarized light propagates counterclockwise through the second autocollimating lens, the angular velocity sensing fiber optic loop, and the first autocollimating lens in sequence.

[0022] The vertically polarized light propagating clockwise and the horizontally polarized light propagating counterclockwise are finally combined into a single beam by the polarization beam splitter.

[0023] Furthermore, the data receiving and processing module also includes a first avalanche photodiode, a first AD data acquisition chip, a second avalanche photodiode, a second AD data conversion chip, and a programmable gate array.

[0024] The first avalanche photodiode and the second avalanche photodiode are used to convert optical signals into electrical signals;

[0025] The first AD data acquisition chip and the second AD data conversion chip are used to convert analog electrical signals into digital signals.

[0026] Furthermore, the data receiving and processing module also includes a computer and / or an LCD display, which are used to display and store the measurement results.

[0027] Furthermore, the angle between the polarization direction of the first polarizer and the vertical direction is α = π / 4, and the polarized light becomes after pre-selection as follows:

[0028] |φ i >= sin(a)|H>+cos(a)|V>

[0029] Where: |φ i The quantum state that was previously selected corresponds to the quantum state with the polarization direction along the horizontal direction, and the quantum state with the polarization direction along the vertical direction.

[0030] Furthermore, the first, second, and third polarizers are adjusted to the same polarization angle, and the quantum attitude of the photon after passing through and being selected becomes:

[0031]

[0032] Where: |φ f The quantum state selected after the corresponding polarization is β, which is the angle between the polarization direction of the synthesized polarized beam after passing through the second polarizer and the horizontal direction.

[0033] Furthermore, the autocorrelation coefficient under environmental noise equal:

[0034]

[0035]

[0036] Where: I1(t) represents the signal detected by the first avalanche photodiode, I2(t) represents the signal detected by the second avalanche photodiode, and N(t) is the noise in the environment.

[0037] Furthermore, the sampling frequency range of the first AD data acquisition chip and the second AD data conversion chip is 1-1000MHz.

[0038] Compared with the prior art, the present invention has significant advantages and beneficial effects, specifically reflected in the following aspects:

[0039] The programmable gate array (FPGA) in this invention is the core control unit of the entire device. It can generate control signals for the electro-optic modulator, achieving time synchronization in measurement and real-time data processing and display. Two autocorrelation quantum measurements can measure the time-autocorrelated measurement signal, and further calculate the autocorrelation coefficient of the signal. The autocorrelation coefficient obtained under environmental noise can be approximately equal to the theoretical value, thus demonstrating the ability of the fiber optic gyroscope based on autocorrelation quantum weak measurement to resist environmental noise. The sampling frequency of the AD data acquisition chip and the operating frequency of the FPGA directly affect the gyroscope's noise resistance. Theoretically, using a higher frequency AD data acquisition chip and FPGA can further improve the measurement accuracy and robustness. The fiber optic gyroscope based on autocorrelation quantum weak measurement can realize the measurement of the gyroscope's rotational angular velocity under strong environmental noise. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structure of a fiber optic gyroscope based on autocorrelation quantum weak measurement in an embodiment of the present invention.

[0041] Explanation of reference numerals in the attached figures:

[0042] 11-Pre-selective polarization module; 111-Laser; 112-Electro-optic modulator; 113-First polarizer;

[0043] 12- Beam splitter;

[0044] 13-Weakly coupled module; 131-Polarization beam splitter; 132-First autocollimating lens; 133-Angular velocity sensing fiber optic loop; 134-Second autocollimating lens;

[0045] 14- Then select the polarization module;

[0046] 141 - Second polarizer; 142 - Third polarizer;

[0047] 15-Data receiving and processing module;

[0048] 151-First avalanche photodiode; 152-First AD data acquisition chip; 153-Second avalanche photodiode; 154-Second AD data conversion chip; 155-Programmable gate array; 156-Computer; 157-LCD display. Detailed Implementation

[0049] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] In the description of this invention, it should be noted that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0051] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the directional terms such as front, back, top, and bottom are defined according to the location of the components in the drawings and their relative positions to each other, and are only for the purpose of clarity and convenience in expressing the technical solution. It should be understood that these are relative concepts and can vary accordingly depending on different ways of use and placement, and the use of these directional terms should not limit the scope of protection claimed in this application.

[0052] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0053] Please refer to Figure 1 As shown, this embodiment of the invention provides a fiber optic seismic gyroscope based on autocorrelation quantum weak measurement, including a gyroscope carrier for emitting photon signals and an optical module for measuring the angular velocity of the gyroscope carrier. The optical module includes a pre-selective polarization module 11, a beam splitter 12, a weak coupling module 13, a post-selective polarization module 14, and a data receiving and processing module 15.

[0054] The pre-selection polarization module 11 is used to adjust the photon to its quantum state; the beam splitter 12 is used to split the photon after adjustment by the pre-selection polarization module 11 into two beams to achieve time-autocorrelation quantum weak measurement; the weak coupling module 13 is used to achieve weak coupling of the incoming polarized light to achieve quantum weak measurement; the post-selection polarization module 14 includes a second polarizer 141 and a third polarizer 142, where the second polarizer 141 is used for post-selection in quantum measurement and the third polarizer 142 is used for post-selection in standard quantum weak measurement; the data receiving and processing module 15 includes a programmable gate array 155 for generating control signals, which analyzes and processes the measurement data and calculates the autocorrelation coefficient Θ(t) of the signal in real time to obtain the rotational angular velocity Ω of the gyroscope.

[0055] The functional relationship between the autocorrelation coefficient Θ(t) and the rotational angular velocity Ω of the gyroscope is expressed as follows:

[0056]

[0057] Where: β represents the angle between the polarization direction of the synthesized polarized beam after passing through the second polarizer 141 and the horizontal direction, c represents the speed of light in vacuum, N represents the number of turns of the fiber ring, S represents the area of ​​the fiber ring, and ω represents the width of the time-domain Gaussian pointer.

[0058] Specifically, in the embodiments of the present invention Figure 1 The diagram illustrates the design principle of a fiber optic gyroscope based on autocorrelation quantum weak measurement in a high-noise environment, as described in an embodiment of the present invention.

[0059] In a high-noise environment, taking the angular velocity Ω of the measuring instrument rotating in the plane shown in the figure as an example, by appropriately selecting the pre-selected state and the post-selected state of the photon state, and then according to the Sagnac effect, the angular velocity sensing fiber ring couples the rotational angular velocity information into the phase difference of the polarized light. After the data receiving and processing module 15 calculates the autocorrelation coefficient of the autocorrelation quantum weak measurement, the relationship between the autocorrelation coefficient Θ(t) and the rotational angular velocity Ω is obtained.

[0060] Compared to traditional fiber optic seismic gyroscopes, the fiber optic seismic gyroscope in this embodiment of the invention has higher robustness and measurement accuracy in high-noise environments; compared to free-path photonic gyroscopes, the introduction of fiber optic loops can effectively reduce the size of the instrument, thereby meeting the requirements of portable seismic gyroscopes.

[0061] Specifically, please refer to Figure 1As shown, in some preferred embodiments of the present invention, the pre-selective polarization module 11 includes a laser 111, an electro-optic modulator 112 and a first polarizer 113. The laser beam emitted by the laser 111 forms a Gaussian waveform in time after passing through the electro-optic modulator 112, and then the quantum state of the photon is adjusted by the first polarizer 113.

[0062] Please see Figure 1 As shown, in a specific embodiment of the present invention, the beam splitter 12 splits the photons after passing through the pre-selective polarization module 11 into two beams, wherein:

[0063] A photon in a beam of light completes a standard quantum weak measurement after undergoing quantum weak coupling and quantum postselection.

[0064] Photons in another beam undergo quantum postselection to perform time-autocorrelated measurements, thus realizing time-autocorrelated quantum weak measurements.

[0065] Specifically, please refer to Figure 1 As shown, in some preferred embodiments of the present invention, the weakly coupled module 13 includes a polarization beam splitter 131, a first autocollimating lens 132, an angular velocity sensing fiber ring 133, and a second autocollimating lens 134. The polarization beam splitter 131 splits linearly polarized light into vertically polarized light polarized in the vertical direction and horizontally polarized light polarized in the horizontal direction. The first autocollimating lens 132 and the second autocollimating lens 134 are used to connect the free light path with the angular velocity sensing fiber ring 133.

[0066] Thus, photons enter the weak coupling module 13, achieving weak coupling for quantum weak measurement. The polarization beam splitter 131 separates the Gaussian pulse beam into vertically polarized light V and horizontally polarized light H, wherein the vertically polarized light V is polarized along the vertical direction, and the horizontally polarized light H is polarized along the horizontal direction.

[0067] Then, the vertically polarized light V propagates clockwise through the first autocollimating lens 132, the angular velocity sensing fiber ring 133, and the second autocollimating lens 134 before returning to the polarization beam splitter 131.

[0068] Meanwhile, the horizontally polarized light H propagates counterclockwise, passing sequentially through the second autocollimating lens 134, the angular velocity sensing fiber ring 133, and the first autocollimating lens 132 before returning to the polarization beam splitter 131.

[0069] A coupled beam is formed by the weak coupling of clockwise propagating vertically polarized light V and counterclockwise propagating horizontally polarized light H. The first autocollimating lens 132 and the second autocollimating lens 134 are used to connect the free optical path to the angular velocity sensing fiber optic loop 133.

[0070] Specifically, please refer to Figure 1As shown, in some preferred embodiments of the present invention, the data receiving and processing module 15 includes a first avalanche photodiode 151, a first AD data acquisition chip 152, a second avalanche photodiode 153, and a second AD data conversion chip 154, wherein:

[0071] The first avalanche photodiode 151 and the second avalanche photodiode 153 are used to receive the converging light beam and convert the intensity of the light signal into an electrical signal.

[0072] The first AD data acquisition chip 152 and the second AD data conversion chip 154 ​​are used to convert analog electrical signals into digital signals.

[0073] Specifically, please refer to Figure 1 As shown, in some preferred embodiments of the present invention, the sampling frequency range of the first AD data acquisition chip 152 and the second AD data conversion chip 154 ​​is 1-1000MHz.

[0074] Therefore, the first AD data acquisition chip 152 and the second AD data conversion chip 154 ​​are used to convert the voltage signal into a digital signal.

[0075] Specifically, please refer to Figure 1 As shown, in some preferred embodiments of the present invention, the data receiving and processing module further includes a computer 156 and / or an LCD display 157, the computer 156 and / or the LCD display 157 being used to display and store the measurement results.

[0076] Specifically, please refer to Figure 1 As shown, in an embodiment of the present invention, the post-selection polarization module 14 includes a second polarizer 141 and a third polarizer 142, wherein:

[0077] The second polarizer 141 is used for post-selection in quantum measurement, and the third polarizer 142 is used for post-selection in standard quantum weak measurement.

[0078] Specifically, in an embodiment of the present invention, the laser 111 is composed of a 780nm diode.

[0079] The laser beam of a certain intensity emitted by the laser 111 is transformed into a Gaussian beam in the time domain after passing through the electro-optic modulator 112. The change of its intensity over time is a Gaussian function with a fixed period. The waveform of the intensity is controlled by the modulation signal generated by the programmable gate array (FPGA) 155, which enables precise timing control. Subsequently, the beam passes through the first polarizer 113 to complete the pre-selection of quantum weak measurement.

[0080] Specifically, in an embodiment of the present invention, the angle between the polarization direction of the first polarizer 113 and the vertical direction is α = π / 4, and the polarized light becomes after pre-selection as follows:

[0081] |φ i >=sin(a)|H>+cos(a)|V>where: |φ i The quantum state that was previously selected corresponds to the quantum state with the polarization direction along the horizontal direction, and the quantum state with the polarization direction along the vertical direction.

[0082] Beam splitter 12 divides the light beam into two beams, thereby enabling time-autocorrelated quantum weak measurements. Photons in one beam undergo quantum weak coupling and quantum post-selection to complete a standard quantum weak measurement.

[0083] Finally, the signal is measured by the second avalanche photodiode 153 to obtain the signal I2(t,τ) of light intensity changing with time, where τ is the time delay caused by the rotation of the gyroscope.

[0084] After quantum post-selection, the photons in the other beam undergo time autocorrelation measurement, and finally the signal is measured by the second avalanche photodiode 153 to obtain the light intensity change signal I1(t) over time.

[0085] According to the autocorrelation quantum weak measurement principle, in the absence of noise, the final observed signals I1(t) and I2(t,τ) differ by only one time delay τ, which can be measured by autocorrelation detection technology.

[0086] The polarization beam splitter 131 splits linearly polarized light into vertically polarized light V and horizontally polarized light H.

[0087] The first autocollimating lens 132 and the second autocollimating lens 134 can connect the propagation of photons between the free light path and the optical fiber. Vertically polarized light V, polarized in the vertical direction, propagates clockwise through the first autocollimating lens 132, the angular velocity sensing fiber loop 133 and the second autocollimating lens 134.

[0088] The horizontally polarized light H propagates counterclockwise through the second autocollimating lens 134, the angular velocity sensing fiber ring 133, and the first autocollimating lens 132. Finally, the two polarized beams are combined into one beam by the polarization beam splitter 131.

[0089] This process corresponds to weak coupling in quantum weak measurement, where the generalized Sagnac effect creates a phase difference between clockwise and counterclockwise polarized light. This phase difference It will cause a tiny time delay τ in the arrival time of photons, which can be obtained through the principle of quantum weak measurement and the Sagnac effect:

[0090]

[0091] Where: c is the speed of light in vacuum, N is the number of turns of the fiber optic loop, Ω is the magnitude of the rotational angular velocity, and S is the area of the fiber optic loop.

[0092] Specifically, in the embodiments of the present invention, the second polarizer 141 and the third polarizer 142 are adjusted to the same polarization angle, and the quantum state of the photons becomes after passing through the post-selection:

[0093]

[0094] Where: |φ f > corresponds to the post-selected quantum state, and β is the angle between the polarization direction of the synthesized polarized light beam after passing through the second polarizer and the horizontal direction.

[0095] The observable operator corresponding in the present invention is: A = |H><H| - |V><V|, and according to the weak value A in quantum weak measurement W The definition of:

[0096]

[0097] According to the principle of weak value amplification in quantum weak measurement, when mutually orthogonal pre-selected states and post-selected states are selected, the value of A w is infinity, so as to amplify the time delay τ in the fiber optic loop into the movement Δt of the pointer, and the magnitude of Δt is proportional to the real part of the weak value: Δt = τRe[A w = τcot(β). At this time, the time delay τ is amplified by cot(β) times due to the principle of weak mass amplification.

[0098] Traditional quantum weak measurement is to detect the movement Δt of the pointer, but this measurement method will lead to negative (invalid) measurements in a strong noise environment. However, in self-correlated quantum weak measurement, what is finally measured is the autocorrelation coefficient Θ(t) of the signals I1(t) and I2(t,τ) detected by two avalanche diodes. Measuring the autocorrelation coefficient Θ(t) has been proven to be robust against Gaussian white noise theoretically.

[0099] When the light beam waveform modulated by the electro-optic modulator 112 is a Gaussian waveform, its light intensity (after normalization) changes with time as:

[0100]

[0101] Where: ω is the width of the Gaussian pointer, and the light intensity signals detected by the first avalanche photodiode 151 and the second avalanche photodiode 153 are:

[0102]

[0103]

[0104] The movement of the probe pointer here is Δt = 4NΩScot(β) / c 2 The expressions for I1(t) and I2(t,τ) can be obtained. Theoretically, the difference between the two signals is only a time delay Δt, which can be obtained by measuring the autocorrelation coefficients of the two signals.

[0105]

[0106] From this, we can obtain the relationship between the autocorrelation coefficient Θ(t) of the autocorrelation quantum weak measurement and the magnitude of the gyroscope rotational angular velocity Ω to be measured.

[0107] In a noisy environment, the noise can be considered to be directly applied to the signals I1(t) and I2(t,τ). In this case, the autocorrelation coefficient under environmental noise... equal:

[0108]

[0109]

[0110] Among them, the autocorrelation coefficients between noises and between noise and signal, when the number of integration points is sufficiently large, can be considered.

[0111] ∫I1(t)×N(t)dt=∫I2(t)×N(t)dt=∫N(t)×N(t)dt≈0

[0112] The reason is that noise is time-independent with each other and with the signal. The measured autocorrelation coefficient Θ(t) remains unchanged in theory, a property derived from the robustness of autocorrelation quantum weak measurement against environmental noise.

[0113] Specifically, in the embodiments of the present invention, the calculation of the autocorrelation is implemented by the data receiving and processing module 15. Wherein:

[0114] The first avalanche photodiode 151 and the first AD data acquisition chip 152 are used to measure and obtain the signal I1(t); the second avalanche photodiode 153 and the second AD data conversion chip 154 ​​are used to measure and obtain the signal I2(t).

[0115] The programmable gate array (FPGA) 155 can perform data multiplication and integration in real time and obtain the autocorrelation coefficient Θ(t).

[0116] The final measurement results can be read, displayed, and stored by a host computer programmed on the computer 156; or they can be displayed on an LCD display 157.

[0117] The above process is based on the principle of weak value amplification of autocorrelation quantum weak measurement under strong environmental noise conditions: by appropriately pre-selecting and post-selecting the quantum state, the angular velocity of the gyroscope rotation is converted into a time delay through the angular velocity sensing fiber loop 133; finally, the relationship between the autocorrelation signal of the two autocorrelation measurement results and the angular velocity to be measured is obtained by calculating the autocorrelation signal of the two autocorrelation measurement results.

[0118] In this embodiment, the robustness of the gyroscope based on autocorrelation quantum weak measurement in strong ambient noise depends on the speed and accuracy of the data receiving and processing module 15.

[0119] Correspondingly, the higher the acquisition rate of the first AD data acquisition chip 152 and the second AD data conversion chip 154, and the higher the operating frequency of the programmable gate array (FPGA) 155, the more scoring points there are within the signal period of the Gaussian pointer, and the higher the value of the autocorrelation coefficient under noise conditions. The closer the gyroscope is to the theoretical value Θ(t), the better its robustness in strong environmental noise.

[0120] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the scope of protection of this invention.

Claims

1. A fiber optic seismic gyroscope based on autocorrelation quantum weak measurement, characterized in that... It includes a gyroscope carrier for emitting photon signals and an optical module for measuring the rotational angular velocity of the gyroscope carrier, the optical module further including: A pre-selective polarization module (11) is used to adjust to the quantum state of a photon; A beam splitter (12) is used to split the photons after adjustment by the pre-selective polarization module (11) into two beams to achieve time-autocorrelated quantum weak measurement; The weak coupling module (13) is used to achieve weak coupling of the incoming polarized light for quantum weak measurement; The post-selection polarization module (14) includes a second polarizer (141) and a third polarizer (142), the second polarizer (141) being used for post-selection in quantum measurement and the third polarizer (142) being used for post-selection in standard weak quantum measurement; The data receiving and processing module (15) includes a programmable gate array (155) for generating control signals. The programmable gate array (155) analyzes and processes the measurement data to obtain the autocorrelation coefficient Θ(t), thereby obtaining the rotational angular velocity Ω of the gyroscope. The functional relationship between the autocorrelation coefficient Θ(t) and the rotational angular velocity Ω of the gyroscope is expressed as follows: Θ(t)= in: The angle between the polarization direction of the synthesized polarized beam after passing through the second polarizer (141) and the horizontal direction is represented by c, which represents the speed of light in vacuum, N represents the number of turns of the fiber ring, S represents the area of ​​the fiber ring, and ω represents the width of the time-domain Gaussian pointer.

2. The fiber optic seismic gyroscope based on autocorrelation quantum weak measurement according to claim 1, characterized in that, The pre-selective polarization module (11) includes a laser (111), an electro-optic modulator (112), and a first polarizer (113). The laser beam emitted by the laser (111) forms a Gaussian waveform in time after passing through the electro-optic modulator (112), and then the quantum state of the photon is adjusted by the first polarizer (113).

3. The fiber optic seismic gyroscope based on autocorrelation quantum weak measurement according to claim 2, characterized in that, The weakly coupled module (13) includes a polarization beam splitter (131), a first autocollimating lens (132), an angular velocity sensing fiber ring (133), and a second autocollimating lens (134). The polarization beam splitter (131) splits linearly polarized light into vertically polarized light polarized in the vertical direction and horizontally polarized light polarized in the horizontal direction. The first autocollimating lens (132) and the second autocollimating lens (134) are used to realize the connection between the free optical path and the angular velocity sensing fiber ring (133). The vertically polarized light propagates clockwise through the first autocollimating lens (132), the angular velocity sensing fiber ring (133), and the second autocollimating lens (134) in sequence; The horizontally polarized light propagates counterclockwise through the second autocollimating lens (134), the angular velocity sensing fiber ring (133), and the first autocollimating lens (132) in sequence; The vertically polarized light propagating clockwise and the horizontally polarized light propagating counterclockwise are finally combined into a single beam by the polarization beam splitter (131).

4. The fiber optic seismic gyroscope based on autocorrelation quantum weak measurement according to claim 2, characterized in that, The data receiving and processing module (15) further includes a first avalanche photodiode (151), a first AD data acquisition chip (152), a second avalanche photodiode (153), and a second AD data conversion chip (154), wherein: The first avalanche photodiode (151) and the second avalanche photodiode (153) are used to convert optical signals into electrical signals; The first AD data acquisition chip (152) and the second AD data conversion chip (154) are used to convert analog electrical signals into digital signals.

5. The fiber optic seismic gyroscope based on autocorrelation quantum weak measurement according to claim 1, characterized in that, The data receiving and processing module (15) further includes a computer (156) and / or an LCD display (157), which are used to display and store the measurement results.

6. The fiber optic seismic gyroscope based on autocorrelation quantum weak measurement according to claim 4, characterized in that, The polarization direction of the first polarizer (113) makes an angle of α = π / 4 with the vertical direction. After the polarized light passes through the pre-selection, it becomes: in: The quantum state that was previously selected corresponds to the quantum state with the polarization direction along the horizontal direction, and the quantum state with the polarization direction along the vertical direction.

7. The fiber optic seismic gyroscope based on autocorrelation quantum weak measurement according to claim 6, characterized in that, The first polarizer (113), the second polarizer (141), and the third polarizer (142) are adjusted to the same polarization angle. After the photon passes through the polarizer, its quantum state becomes: | >= sin( ) + cos( ) in: The quantum state selected after correspondence The angle between the polarization direction of the synthesized polarized beam and the horizontal direction after passing through the second polarizer.

8. The fiber optic seismic gyroscope based on autocorrelation quantum weak measurement according to claim 7, characterized in that, Autocorrelation coefficient under environmental noise (t) equals: Θ(t) in: The signal detected by the first avalanche photodiode (151) represents the signal detected by the first avalanche photodiode. This represents the signal detected by the second avalanche photodiode (153). This refers to noise in the environment.

9. The fiber optic seismic gyroscope based on autocorrelation quantum weak measurement according to claim 4, characterized in that, The sampling frequency range of the first AD data acquisition chip (152) and the second AD data conversion chip (154) is 1-1000MHz.

10. The fiber optic seismic gyroscope based on autocorrelation quantum weak measurement according to claim 2, characterized in that, The laser (111) is composed of a 780nm diode.

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