A system for suppressing transverse optical frequency shift in a spin-exchange relaxation inertial measurement device.

Abstract

A system for suppressing lateral optical frequency shift in a spin-free exchange-relaxation inertial measurement unit (SMU) is disclosed. Taking the SMU as the research object, this invention addresses the problem of lateral optical frequency shift caused by detection laser detuning. It employs a method using two detection lasers, one blue-detuned and one red-detuned, for detection. Simultaneously, it utilizes optical rotation angle information to adjust the frequencies of the two detection lasers, causing the lateral optical frequency shifts caused by the blue-detuned detection laser and the red-detuned laser to cancel each other out, thus establishing a lateral optical frequency shift suppression scheme. Based on a spin-free exchange-relaxation inertial measurement unit, this invention meets the design requirements for signal detection using a far-detuned linearly polarized light detection laser while suppressing lateral optical frequency shift errors and improving the signal-to-noise ratio. It is applicable to products such as spin-free exchange-relaxation inertial / magnetic field measurement units and has a very broad prospect.

Description

Technical Field

[0001] This invention belongs to the technical field of spin-free exchange-relaxation inertial measurement devices, specifically relating to a system for suppressing lateral optical frequency shift in spin-free exchange-relaxation inertial measurement devices. Background Technology

[0002] In recent years, with the development of physics and optical engineering, research related to quantum sensing has also progressed rapidly. Among them, spin-free exchange-relaxation inertial measurement units (SMUs) have the potential to achieve both high accuracy and small size, making them one of the research frontiers for next-generation inertial navigation. The transverse optical frequency shift in spin-free exchange-relaxation inertial measurement units affects the accuracy of the detection system, and suppressing the transverse optical frequency shift is of great significance for high-precision spin-free exchange-relaxation inertial measurement units.

[0003] Currently, methods for eliminating transverse optical frequency shifts mainly involve adjusting the laser frequency or the temperature of the alkali metal gas chamber to cancel out the transverse optical frequency shifts generated by different alkali metal atoms. However, in practical applications, the laser frequency or the temperature of the alkali metal atom gas chamber also affects the polarizability of the system atoms. This is crucial for spin-free exchange relaxation inertial measurement devices. Furthermore, achieving transverse optical frequency shift cancellation often cannot simultaneously maintain high atomic polarizability.

[0004] In summary, with the advancements in quantum physics, the design of transverse optical frequency shift elimination has broad prospects, but practical research in this area is still relatively lacking. This invention, taking a holistic approach, studies a method for eliminating transverse optical frequency shift in spin-free exchange-relaxation inertial measurement devices, which will provide guidance and reference for the design of transverse optical frequency shift elimination in similar gas-based spin-free exchange-relaxation inertial / magnetic field measurement devices. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the transverse optical frequency shift error caused by the detuning of the detection laser system, and to provide a system for suppressing transverse optical frequency shift in a spin-exchange relaxation inertial measurement device, so as to suppress transverse optical frequency shift.

[0006] The technical solution of the present invention is as follows:

[0007] A system for suppressing lateral optical frequency shift in a spin-exchange relaxation inertial measurement device is characterized by comprising a third stable light intensity system disposed on the pump optical path on the left side of the alkali metal gas cell, a second stable light intensity system disposed on the second detection optical path below the alkali metal gas cell, and a first stable light intensity system disposed on the first detection optical path above the alkali metal gas cell. A first detection light emitted from the first stable light intensity system passes sequentially through a first depolarization beam splitter and the alkali metal gas cell, and is then reflected by the second depolarization beam splitter to a second photoelectric detection differential processing system. The second photoelectric detection differential processing system is connected to the second channel of a signal processor. A second detection light emitted from the second stable light intensity system passes sequentially through the second depolarization beam splitter and the alkali metal gas cell, and is then reflected by the first depolarization beam splitter to the first photoelectric detection differential processing system. The first photoelectric detection differential processing system is connected to the first channel of a signal processor. The pump light emitted from the third stable light intensity system illuminates the alkali metal gas cell through a quarter-wave plate.

[0008] The first detection light (blue) is detuned to the alkali metal atomic resonance line, and the second detection light (red) is detuned to the alkali metal atomic resonance line. The first detection light and the second detection light cancel each other out due to the transverse optical frequency shifts of opposite signs, thereby achieving suppression of the transverse optical frequency shift.

[0009] The signal processor obtains the linear polarization plane rotation angle information of the first and second detection lights after passing through the gas cell. By adjusting the frequencies of the two detection lasers, the signal magnitudes of the two channels of the signal processor are made equal, thereby achieving the effect of suppressing transverse light frequency shift.

[0010] The first photoelectric detection differential processing system includes a first differential node. The output of the first differential node is connected to the first channel of the signal processor. The first input of the first differential node is connected to the reflection side of the sixth polarization beam splitter through a third photodetector. The second input of the first differential node is connected to the transmission side of the sixth polarization beam splitter through a fourth photodetector. The input side of the sixth polarization beam splitter is connected to the reflection side of the first depolarization beam splitter through a third half-wave plate.

[0011] The second photoelectric detection differential processing system includes a second differential node. The output of the second differential node is connected to the second channel of the signal processor. The first input of the second differential node is connected to the reflection side of the third polarization beam splitter through a sixth photodetector. The second input of the second differential node is connected to the transmission side of the third polarization beam splitter through a fifth photodetector. The input side of the third polarization beam splitter is connected to the reflection side of the second depolarization beam splitter through a fourth half-wave plate.

[0012] The first stable light intensity system includes a fourth polarizing beam splitter, a second liquid crystal phase retarder, a second half-wave plate, and a fifth polarizing beam splitter connected in series. The transmission side of the fifth polarizing beam splitter is connected to a first depolarizing beam splitter, and the reflection side of the fifth polarizing beam splitter is connected to the second liquid crystal phase retarder via a second photodetector. The fourth polarizing beam splitter is connected to a first detection laser via a first optical isolator. The second stable light intensity system includes an eighth polarizing beam splitter, a fifth half-wave plate, a third liquid crystal phase retarder, and a seventh polarizing beam splitter connected in series. The transmission side of the seventh polarizing beam splitter is connected to the second depolarizing beam splitter, and the reflection side of the seventh polarizing beam splitter is connected to the third liquid crystal phase retarder via a seventh photodetector. The eighth polarizing beam splitter is connected to a second detection laser via a second optical isolator.

[0013] The fourth polarizing beam splitter is perpendicular to the optical axis of the fifth polarizing beam splitter. After achieving extinction by adjusting the second half-wave plate, the intensity of the first detection light is stably controlled by controlling the voltage of the second liquid crystal phase retarder. The eighth polarizing beam splitter is perpendicular to the optical axis of the seventh polarizing beam splitter. After achieving extinction by adjusting the fifth half-wave plate, the intensity of the second detection light is stably controlled by controlling the voltage of the third liquid crystal phase retarder. In the alkali metal gas cell, the intensity of the first detection light is equal to the intensity of the second detection light.

[0014] The alkali metal chamber contains potassium, rubidium, or cesium atoms, and is filled with nitrogen and helium.

[0015] The third stable light intensity system includes a first polarizing beam splitter, a first liquid crystal phase retarder, a first half-wave plate, and a second polarizing beam splitter connected in series. The transmission side of the second polarizing beam splitter is connected to the half-wave plate, and the reflection side of the second polarizing beam splitter is connected to the first liquid crystal phase retarder through a first photodetector. The first polarizing beam splitter is connected to a pump laser.

[0016] The technical effects of this invention are as follows: This invention provides a system for suppressing lateral optical frequency shift in a spin-free exchange-relaxation inertial measurement unit (SMU). Taking a spin-free exchange-relaxation SMU as the research object, it addresses the problem of lateral optical frequency shift caused by detection laser detuning. It employs a method of detection using two lasers, one blue-detuned and one red-detuned, and simultaneously utilizes optical rotation angle information to adjust the frequencies of the two detection lasers, causing the lateral optical frequency shifts caused by the blue-detuned detection laser and the red-detuned laser to cancel each other out, thus establishing a lateral optical frequency shift suppression scheme. Based on a spin-free exchange-relaxation SMU, this invention, while meeting the design requirements of using far-detuned linearly polarized light detection lasers for signal detection, suppresses lateral optical frequency shift errors and improves the signal-to-noise ratio. It is suitable for products such as spin-free exchange-relaxation inertial / magnetic field measurement units and has a very broad prospect.

[0017] The advantages of this invention compared to existing technologies are as follows: This invention uses two detection lasers with opposite detuning directions to detect atomic signals, which satisfies the requirement of suppressing transverse optical frequency shift without affecting the optimal operating point of other system parameters. At the same time, it utilizes the information of optical rotation angle to adjust the frequency of the two detection lasers more precisely, further improving the suppression efficiency. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a system for suppressing lateral optical frequency shift in a spin-free exchange relaxation inertial measurement device according to the present invention.

[0019] The reference numerals in the attached figures are listed below: 1-Pump laser; 2-First polarizing beam splitter; 3-First liquid crystal phase retarder; 4-First half-wave plate; 5-Second polarizing beam splitter; 6-First photodetector; 7-Half-wave plate; 8-Alkali metal gas cell; 9-First detection laser; 10-First optical isolator; 11-Fourth polarizing beam splitter; 12-Second liquid crystal phase retarder; 13-Second half-wave plate; 14-Second photodetector; 15-Fifth polarizing beam splitter; 16-First depolarizing beam splitter; 17-Third... 18-Third waveplate; 19-Sixth polarizing beam splitter; 20-Fourth photodetector; 21-Signal processor; 22-Second depolarizing beam splitter; 23-Fourth half-waveplate; 24-Third polarizing beam splitter; 25-Sixth photodetector; 26-Fifth photodetector; 28-Seventh polarizing beam splitter; 29-Seventh photodetector; 30-Third liquid crystal phase retarder; 31-Fifth half-waveplate; 32-Eighth polarizing beam splitter; 33-Second optical isolator; 34-Second detection laser. Detailed Implementation

[0020] The following is in conjunction with the attached diagram ( Figure 1 The invention will be described in the following sections and examples.

[0021] Figure 1 This is a schematic diagram of the system structure for suppressing lateral optical frequency shift in a spin-free exchange-relaxation inertial measurement device according to the present invention. (Reference) Figure 1 As shown, a system for suppressing lateral optical frequency shift in a spin-exchange relaxation inertial measurement device includes a third stable light intensity system disposed on the pump optical path on the left side of the alkali metal gas cell 8, a second stable light intensity system disposed on the second detection optical path below the alkali metal gas cell 8, and a first stable light intensity system disposed on the first detection optical path above the alkali metal gas cell 8. The first detection light emitted from the first stable light intensity system passes sequentially through the first depolarization beam splitter 16 and the alkali metal gas cell 8 and is then reflected by the second depolarization beam splitter 22 to the second photoelectric detection differential processing system. The second photoelectric detection differential processing system is connected to the second channel of the signal processor 21. The second detection light emitted from the second stable light intensity system passes sequentially through the second depolarization beam splitter 22 and the alkali metal gas cell 8 and is then reflected by the first depolarization beam splitter 16 to the first photoelectric detection differential processing system. The first photoelectric detection differential processing system is connected to the first channel of the signal processor 21. The pump light emitted from the third stable light intensity system illuminates the alkali metal gas cell 8 through a quarter-wave plate 7. The first detection light (blue) is detuned to the alkali metal atomic resonance line, and the second detection light (red) is detuned to the alkali metal atomic resonance line. The first and second detection lights cancel each other out due to opposite transverse optical frequency shifts, thereby suppressing the transverse optical frequency shift. The signal processor 21 obtains the linear polarization plane rotation angle information of the first and second detection lights after passing through the gas cell. By adjusting the frequencies of the two detection lasers, the signal magnitudes of the two channels of the signal processor 21 are made equal, thereby achieving the effect of suppressing the transverse optical frequency shift.

[0022] The first photoelectric detection differential processing system includes a first differential node. The output of the first differential node is connected to the first channel of the signal processor 21. The first input of the first differential node is connected to the reflection side of the sixth polarizing beam splitter 19 via a third photodetector 18. The second input of the first differential node is connected to the transmission side of the sixth polarizing beam splitter 19 via a fourth photodetector 20. The input side of the sixth polarizing beam splitter 19 is connected to the reflection side of the first depolarizing beam splitter 16 via a third half-wave plate 17. The second photoelectric detection differential processing system includes a second differential node. The output of the second differential node is connected to the second channel of the signal processor 21. The first input of the second differential node is connected to the reflection side of the third polarizing beam splitter 24 via a sixth photodetector 25. The second input of the second differential node is connected to the transmission side of the third polarizing beam splitter 24 via a fifth photodetector 26. The input side of the third polarizing beam splitter 24 is connected to the reflection side of the second depolarizing beam splitter 22 via a fourth half-wave plate 23.

[0023] The first light intensity stabilization system includes a fourth polarizing beam splitter 11, a second liquid crystal phase retarder 12, a second half-wave plate 13, and a fifth polarizing beam splitter 15 connected in series. The transmission side of the fifth polarizing beam splitter 15 is connected to a first depolarizing beam splitter 16, and the reflection side of the fifth polarizing beam splitter 15 is connected to the second liquid crystal phase retarder 12 through a second photodetector 14. The fourth polarizing beam splitter 11 is connected to a first detection laser 9 through a first optical isolator 10. The second light intensity stabilization system includes an eighth polarizing beam splitter 32, a fifth half-wave plate 31, a third liquid crystal phase retarder 30, and a seventh polarizing beam splitter 28 connected in series. The transmission side of the seventh polarizing beam splitter 28 is connected to a second depolarizing beam splitter 22, and the reflection side of the seventh polarizing beam splitter 28 is connected to the third liquid crystal phase retarder 30 through a seventh photodetector 29. The eighth polarizing beam splitter 32 is connected to a second detection laser 34 through a second optical isolator 33.

[0024] The fourth polarizing beam splitter 11 and the fifth polarizing beam splitter 15 are perpendicular to each other on their optical axes. After achieving extinction by adjusting the second half-wave plate 13, the intensity of the first detection light is stabilized by controlling the voltage of the second liquid crystal phase retarder 12. The eighth polarizing beam splitter 32 and the seventh polarizing beam splitter 28 are perpendicular to each other on their optical axes. After achieving extinction by adjusting the fifth half-wave plate 31, the intensity of the second detection light is stabilized by controlling the voltage of the third liquid crystal phase retarder 30. In the alkali metal gas chamber 8, the intensity of the first detection light is equal to the intensity of the second detection light. The alkali metal gas chamber 8 contains potassium, rubidium, or cesium atoms and is filled with nitrogen and helium gas. The third stable light intensity system includes a first polarizing beam splitter 2, a first liquid crystal phase retarder 3, a first half-wave plate 4, and a second polarizing beam splitter 5 connected in series. The transmission side of the second polarizing beam splitter 5 is connected to the half-wave plate 7, and the reflection side of the second polarizing beam splitter 5 is connected to the first liquid crystal phase retarder 3 through a first photodetector 6. The first polarizing beam splitter 2 is connected to the pump laser 1.

[0025] Figure 1This is a schematic diagram of the transverse optical frequency shift suppression system of a spin-exchange relaxation inertial measurement device according to the present invention. As shown in the figure, the transverse optical frequency shift suppression system of a spin-exchange relaxation inertial measurement device includes a pump laser (1), a first polarizing beam splitter (2), a first liquid crystal phase retarder (3), a first half-wave plate (4), a second polarizing beam splitter (5), a first photodetector (6), a quarter-wave plate (7), an alkali metal gas cell (8), a first detection laser (9), a first optical isolator (10), a fourth polarizing beam splitter (11), a second liquid crystal phase retarder (12), a second half-wave plate (13), and a second photodetector (14). ), Fifth polarizing beam splitter (15), First depolarizing beam splitter (16), Third half-wave plate (17), Third photodetector (18), Sixth polarizing beam splitter (19), Fourth photodetector (20), Signal processor (21), Second depolarizing beam splitter (22), Fourth half-wave plate (23), Third polarizing beam splitter (24), Sixth photodetector (25), Fifth photodetector (26), Seventh polarizing beam splitter (28), Seventh photodetector (29), Third liquid crystal phase retarder (30), Fifth half-wave plate (31), Eighth polarizing beam splitter (32), Second optical isolator (33), Second A detection laser (34) is used; a pump laser (1) generates a beam of monochromatic light that resonates with the D1 line of the alkali metal, which passes sequentially through a first polarizing beam splitter (2), a first liquid crystal phase retarder (3), a first half-wave plate (4), and a second polarizing beam splitter (5) and is split into two beams of light with orthogonal polarization directions. The reflected light is sent to a first photodetector (6) for detection, and the transmitted light passes through a quarter-wave plate (7) and an alkali metal gas cell (8) to pump alkali metal atoms; a first detection laser (9) generates a beam of monochromatic light that is far detuned to the D1 line of the alkali metal atoms, which passes sequentially through a first optical isolator (10), a fourth polarizing beam splitter (11), and a second liquid crystal phase retarder (12). After the second half-wave plate (13) and the fifth polarization beam splitter (15) split the light into two beams with orthogonal polarization directions, the reflected light is sent to the second photodetector (14), and the transmitted light passes through the first depolarization beam splitter (16), the alkali metal gas cell (8), and the second depolarization beam splitter (22) to split the light into two beams of the same size and polarization direction. The reflected light passes through the fourth half-wave plate (23) and the third polarization beam splitter (24) to split the light into two beams with orthogonal polarization directions. The reflected light enters the sixth photodetector (25), and the transmitted light enters the fifth photodetector (26). The signals from the two photodetectors are differentially divided and sent to the signal processor (21) for the instructor to observe.A monochromatic beam of light, far detuned to the D1 line of alkali metal atoms, is generated by a second detection laser (34). This beam passes sequentially through a second optical isolator (33), an eighth polarizing beam splitter (32), a fifth half-wave plate (31), a third liquid crystal phase retarder (30), and a seventh polarizing beam splitter (28), splitting into two beams with orthogonal polarization directions. The reflected light is sent to a second photodetector (14), while the transmitted light passes sequentially through a second depolarizing beam splitter (22), an alkali metal gas cell (8), and a first depolarizing beam splitter (16), splitting into two beams of equal size and polarization direction. The reflected light passes sequentially through a third half-wave plate (17) and a sixth polarizing beam splitter (19), splitting into two beams with orthogonal polarization directions. The reflected light enters a third photodetector (18), and the transmitted light enters a fourth photodetector (20). The signals from the two photodetectors are differentially divided and sent to a signal processor (21) for observation by the instructor.

[0026] The first optical isolator (10) and the second optical isolator (33) in the optical path can be either polarization-independent optical isolators or polarization-dependent optical isolators.

[0027] The sixth polarizing beam splitter (19) is placed orthogonally to the optical axis of the seventh polarizing beam splitter (28). At the same time, the third half-wave plate (17) is adjusted so that the system consisting of the sixth polarizing beam splitter (19), the third half-wave plate (17) and the seventh polarizing beam splitter (28) achieves the extinction effect when the alkali metal gas chamber (8) is not heated. The third polarizing beam splitter (24) is placed orthogonally to the optical axis of the fifth polarizing beam splitter (15). At the same time, the fourth half-wave plate (23) is adjusted so that the system consisting of the third polarizing beam splitter (24), the fourth half-wave plate (23) and the fifth polarizing beam splitter (15) achieves the extinction effect when the alkali metal gas chamber (8) is not heated.

[0028] The fourth polarizing beam splitter (11), the second liquid crystal phase retarder (12), the second half-wave plate (13), the second photodetector (14), and the fifth polarizing beam splitter (15) together constitute the first light intensity stabilization system. The seventh polarizing beam splitter (28), the seventh photodetector (29), the third liquid crystal phase retarder (30), the fifth half-wave plate (31), and the eighth polarizing beam splitter (32) together constitute the second light intensity stabilization system. In the two light intensity stabilization systems, after the optical axes of the two polarizing beam splitters are vertically placed and the half-wave plate is adjusted to achieve the extinction effect, the light intensity after passing through the light intensity stabilization system is stabilized by controlling the voltage of the liquid crystal phase retarder.

[0029] The gas chamber (8) contains potassium, rubidium or cesium atoms, and is filled with nitrogen and helium.

[0030] The first detection laser (9) and the second detection laser (10) are respectively detuned to the blue and red resonance lines of alkali metal atoms, producing transverse optical frequency shifts with opposite signs.

[0031] The transverse optical frequency shift L caused by the first detection laser (9) x1 for:

[0032]

[0033] Where, r e γ is the classical electron radius; c is the speed of light; f is the oscillator intensity; Φ1 is the luminous flux of the first detection laser (9); γ e Where is the electron gyromagnetic ratio; A is the incident cross-sectional area; D(v1) is a term related to the emitted laser frequency v1 of the second detection laser (34), which is:

[0034]

[0035] In the above formula, υ0 is the resonance frequency of the alkali metal atom, and Δυ / 2 is the full width at half maximum (FWHM) of the alkali metal atom absorption photon curve. The transverse optical frequency shift L caused by the second detection laser (34) x2 for:

[0036]

[0037] Where Φ2 is the luminous flux; and D(v2) is a term related to the laser frequency v2 emitted by the first detection laser (9), which is:

[0038]

[0039] By controlling the first and second light intensity stabilization modules, the light flux of the two detection lasers is made equal. Observing the above equation, it can be found that when the frequencies of the two detection lasers satisfy the following equation:

[0040] v1-v0=v0-v2

[0041] We can obtain:

[0042] L x1 +L x2 =0

[0043] Meanwhile, the signals from the third photodetector (18) and the fourth photodetector (20) are differentially processed in channel one of the signal processor (21) to obtain the linear polarization plane rotation angle φ1 of the second detection laser (34) after passing through the alkali metal gas cell (8).

[0044]

[0045] Where l is the length of the light path within the air chamber; n a It represents the atomic number density; The transverse electronic polarization. The signals from the sixth photodetector (25) and the fifth photodetector (26) are differentially processed in channel two of the signal processor (21) to obtain the linear polarization plane rotation angle φ2 of the first detection laser (9) after passing through the alkali metal gas cell (8):

[0046]

[0047] From the above two formulas, it can be seen that when the rotation angles of the linear polarization planes of two laser beams after passing through the gas cell are the same in magnitude but opposite in direction, the following condition can be satisfied:

[0048] v1-v0=v0-v2

[0049] This achieves the effect of suppressing lateral optical frequency shift, namely:

[0050] L x1 +L x2 =0

[0051] Contents not described in detail in this specification are prior art known to those skilled in the art. It is hereby indicated that the above description is intended to help those skilled in the art understand this invention, but does not limit the scope of protection of this invention. Any equivalent substitutions, modifications, improvements, and / or simplifications of the above descriptions that do not depart from the essential content of this invention fall within the scope of protection of this invention.

Claims

1. A system for suppressing transverse optical frequency shift in a spin-exchange relaxation-free inertial measurement device, characterized in that, The system includes a third stable light intensity system on the pump optical path on the left side of the alkali metal gas chamber, a second stable light intensity system on the second detection optical path below the alkali metal gas chamber, and a first stable light intensity system on the first detection optical path above the alkali metal gas chamber. The first detection light emitted from the first stable light intensity system passes sequentially through the first depolarization beam splitter and the alkali metal gas chamber, and is then reflected by the second depolarization beam splitter to the second photoelectric detection differential processing system. The second photoelectric detection differential processing system is connected to the second channel of the signal processor. The second detection light emitted from the second stable light intensity system passes sequentially through the second depolarization beam splitter and the alkali metal gas chamber, and is then reflected by the first depolarization beam splitter to the first photoelectric detection differential processing system. The first photoelectric detection differential processing system is connected to the first channel of the signal processor. The pump light emitted from the third stable light intensity system illuminates the alkali metal gas chamber through a quarter-wave plate. The first detection light (blue) is detuned to the alkali metal atomic resonance line, and the second detection light (red) is detuned to the alkali metal atomic resonance line. The first detection light and the second detection light cancel each other out due to the transverse optical frequency shifts of opposite signs, thereby achieving suppression of the transverse optical frequency shift.

2. The system for suppressing transverse optical frequency shift in the spin-free exchange-relaxation inertial measurement device according to claim 1, characterized in that, The signal processor obtains the linear polarization plane rotation angle information of the first and second detection lights after passing through the gas cell. By adjusting the frequencies of the two detection lasers, the signal magnitudes of the two channels of the signal processor are made equal, thereby achieving the effect of suppressing transverse light frequency shift.

3. The system for suppressing transverse optical frequency shift in the spin-free exchange-relaxation inertial measurement device according to claim 1, characterized in that, The first photoelectric detection differential processing system includes a first differential node. The output of the first differential node is connected to the first channel of the signal processor. The first input of the first differential node is connected to the reflection side of the sixth polarization beam splitter through a third photodetector. The second input of the first differential node is connected to the transmission side of the sixth polarization beam splitter through a fourth photodetector. The input side of the sixth polarization beam splitter is connected to the reflection side of the first depolarization beam splitter through a third half-wave plate.

4. The system for suppressing transverse optical frequency shift in the spin-free exchange-relaxation inertial measurement device according to claim 1, characterized in that, The second photoelectric detection differential processing system includes a second differential node. The output of the second differential node is connected to the second channel of the signal processor. The first input of the second differential node is connected to the reflection side of the third polarization beam splitter through a sixth photodetector. The second input of the second differential node is connected to the transmission side of the third polarization beam splitter through a fifth photodetector. The input side of the third polarization beam splitter is connected to the reflection side of the second depolarization beam splitter through a fourth half-wave plate.

5. The system for suppressing transverse optical frequency shift in the spin-free exchange-relaxation inertial measurement device according to claim 1, characterized in that, The first stable light intensity system includes a fourth polarizing beam splitter, a second liquid crystal phase retarder, a second half-wave plate, and a fifth polarizing beam splitter connected in series. The transmission side of the fifth polarizing beam splitter is connected to a first depolarizing beam splitter, and the reflection side of the fifth polarizing beam splitter is connected to the second liquid crystal phase retarder via a second photodetector. The fourth polarizing beam splitter is connected to a first detection laser via a first optical isolator. The second stable light intensity system includes an eighth polarizing beam splitter, a fifth half-wave plate, a third liquid crystal phase retarder, and a seventh polarizing beam splitter connected in series. The transmission side of the seventh polarizing beam splitter is connected to the second depolarizing beam splitter, and the reflection side of the seventh polarizing beam splitter is connected to the third liquid crystal phase retarder via a seventh photodetector. The eighth polarizing beam splitter is connected to a second detection laser via a second optical isolator.

6. The system for suppressing transverse optical frequency shift in a spin-free exchange-relaxation inertial measurement device according to claim 5, characterized in that, The fourth polarizing beam splitter is perpendicular to the optical axis of the fifth polarizing beam splitter. After achieving extinction by adjusting the second half-wave plate, the intensity of the first detection light is stably controlled by controlling the voltage of the second liquid crystal phase retarder. The eighth polarizing beam splitter is perpendicular to the optical axis of the seventh polarizing beam splitter. After achieving extinction by adjusting the fifth half-wave plate, the intensity of the second detection light is stably controlled by controlling the voltage of the third liquid crystal phase retarder. In the alkali metal gas cell, the intensity of the first detection light is equal to the intensity of the second detection light.

7. The system for suppressing transverse optical frequency shift in the spin-free exchange-relaxation inertial measurement device according to claim 1, characterized in that, The alkali metal chamber contains potassium, rubidium, or cesium atoms, and is filled with nitrogen and helium.

8. The system for suppressing transverse optical frequency shift in the spin-free exchange-relaxation inertial measurement device according to claim 1, characterized in that, The third stable light intensity system includes a first polarizing beam splitter, a first liquid crystal phase retarder, a first half-wave plate, and a second polarizing beam splitter connected in series. The transmission side of the second polarizing beam splitter is connected to the half-wave plate, and the reflection side of the second polarizing beam splitter is connected to the first liquid crystal phase retarder through a first photodetector. The first polarizing beam splitter is connected to a pump laser.

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