A measurement method for detecting optical pumping effect in a SERF inertial measurement system

Abstract

A measurement method for the pumping effect of detection light in a SERF inertial measurement system is proposed. The SERF inertial measurement system is used as the research object. The residual error after the detection light is stabilized is located on the non-ideal linear polarization of the detection light, and a method for real-time measurement of the pumping effect of the detection light is established. This method is based on the steady-state solution of the Bloch equation. Through the polarization information obtained from the amplitude-frequency response and step modulation experiments under different detection light intensities, combined with the real-time output bias, a product term is obtained to evaluate the comprehensive influence of power, frequency and polarization degree on the pumping effect of the detection light. This solves the problem of not quantitatively evaluating the pumping effect caused by the detection light in the past, and provides a theoretical basis for fundamentally suppressing the adverse effects of the pumping effect of the detection light on the system. At the same time, it can also change the problem of low signal-to-noise ratio caused by low detection power in the past.

Description

Technical Field

[0001] The invention relates to a measurement method for detecting an optical pumping effect in a SERF inertial measurement system, belongs to the field of atomic inertial measurement systems, and can also be used in the field of atomic magnetometers. Background Art

[0002] The use of spin exchange light to pump hyperpolarized noble gases has been widely used in sensing rotation speed, measuring Lorentz and CPT (charge-parity-time reversal symmetry breaking) anomalies, etc. Among these applications, the SERF inertial measurement system based on spin-exchange relaxation-free (SERF) technology has the characteristics of high theoretical accuracy, small size, low cost, and small dynamic range. It can be used as a future platform-type inertial navigation system because it has extremely high sensitivity to rotation. The SERF atomic spin inertial measurement system adopts an external structure in which the pumping light and the detection light are orthogonal. The core is a mixture of alkali metals and inert gases. The high stability of the electron spin and nuclear spin states is the core element of the performance of the SERF inertial measurement system. However, the transverse pumping effect generated by the circularly polarized component of the non-ideal linearly polarized detection beam affects the direction and stability of the electron spin.

[0003] Traditional detection of optical pumping effect is generally calculated as a typical value, lacking the mechanism analysis of the impact of detection optical pumping effect on the system, and no direct relationship has been established. There are individual measurement methods, but they cannot be systematically evaluated. It is impossible to fundamentally suppress the adverse impact of detection optical pumping effect on the system, and it also cannot solve the problem of low signal-to-noise ratio caused by low detection power.

[0004] In summary, with the development and popularization of atomic spin magnetic field\inertial measurement technology, quantitative measurement of the pumping effect of detection light is necessary, but practical research in this area is still relatively lacking. The core of this patent is to study the measurement method of the pumping effect of detection light, which provides evaluation criteria and theoretical basis for fundamentally suppressing the pumping effect of detection light and solving the current problem of low signal-to-noise ratio caused by detection power, which is of great significance to improving system stability. Summary of the invention

[0005] The problem solved by the present invention is to solve the measurement problem of detecting light pumping effect, clarify the mechanism of the influence of the detection light pumping effect on the atomic inertial measurement system, overcome the problem that the existing atomic spin inertial measurement system detects the light pumping effect in non-real time and causes the detection light power to be reduced, and provide a judgment standard and a theoretical basis for fundamentally suppressing the pumping effect of the detection light and solving the current problem of low signal-to-noise ratio caused by the detection power, so as to improve the stability of the SERF inertial measurement system.

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

[0007] A method for measuring optical pumping effect in a SERF inertial measurement system, characterized in that it comprises the following steps:

[0008] Step 1: Heat the alkali metal gas chamber of the SERF inertial measurement system to the operating temperature. When the laser polarizes the atoms to a steady state, the magnetic field is compensated using the magnetic field cross-modulation compensation technology. At this time, the inertial measurement system works at the "inertial measurement system compensation point". Test and record the steady-state bias signal V of the inertial measurement system. out , the rotation inertial measurement system obtains the scale factor K of the spin inertial measurement device;

[0009] Step 2: Through the amplitude-frequency response experiment: apply a series of sinusoidal signals of different frequencies on the X-axis, record the peak-to-peak value of the system output, and perform fitting; and the step modulation experiment: continuously change the voltage of the Z-axis coil to change the magnetic field received by the system on the Z-axis, obtain the value of the system output, and perform fitting. Through the above experimental fitting, the optical frequency shift L of the inertial measurement system on the Z-axis is obtained. z , electron relaxation rate and the X-axis optical frequency shift L x ;

[0010] Step 3: Change the Z-axis magnetic field bias B z , continue the amplitude-frequency response experiment and obtain the electronic resonance peak ω under different magnetic field biases e , fit the magnetic field bias with the electron resonance peak to obtain the slowdown factor Q, and then obtain the electronic polarizability through the slowdown factor Thus, R is obtained under the detection light power m s m The measured value of R m s m is a product term, where R m is the pumping rate of the detection light, s m To detect the circular polarization of light;

[0011] Step 4: Repeat steps 1 to 3 at different detection optical powers to obtain R m s m ;

[0012] Step 5: Use the linear least squares fitting method to obtain R m s m and the detection optical power I 0 The linear relationship between: R m s m =K I I 0 +b, b is a constant, K I is the slope, according to K IThe size of can be used to determine the size of the detection light pumping effect in the current SERF inertial measurement system.

[0013] The detection light pumping effect is a component of the residual error after the detection light is stabilized, which is generated by the depolarization of the spherical gas chamber and the circular dichroic absorption of the gas, and affects the steady-state output of the inertial measurement system.

[0014] After the detection light is emitted from the detection laser, it passes through the first polarizer, the detection liquid crystal module, the first analyzer, the first reflector, the first half-wave plate, the Glan Taylor prism, the first quarter-wave plate, the air chamber, and the second half-wave plate in sequence before reaching the first polarization beam splitter prism. The first polarization beam splitter prism is respectively connected to the second photodetector and the third photodetector, the second photodetector and the third photodetector are both connected to the output end of the SERF inertial measurement system, the Glan Taylor prism is connected to the detection liquid crystal module through the first photodetector and the second electric control module in sequence, and an oven, a three-dimensional magnetic field coil and a magnetic shielding structure are arranged around the air chamber.

[0015] The spin inertial measurement device includes a pumping laser. The pumping light emitted by the pumping laser passes through a first lens, a second lens, a second reflector, a second polarizer, a pumping light path liquid crystal module, a second analyzer, a third half-wave plate and a combined prism in sequence, and then passes through an air chamber. The combined prism is connected to the pumping light path liquid crystal module through a fourth photodetector and a first electric control module in sequence.

[0016] By recording different detection optical powers I 0 The steady-state bias signal V of the inertial measurement system under out , the scale factor K of the inertial measurement system is obtained by rotation, and the Z-axis optical frequency shift L of the inertial measurement system is obtained by amplitude-frequency response experiment and step modulation experiment z , electron relaxation rate The electron polarizability is obtained by measuring the slowing factor Q Thus, R under this detection light power is obtained m s m , change the detection light power for fitting, and finally get R m s m and the detection optical power I 0 linear relationship.

[0017] K I The smaller it is, the smaller the pumping effect of the detection light is.

[0018] The technical effects of the present invention are as follows: The present invention provides a measurement method for the pumping effect of detection light in a SERF inertial measurement system. The SERF inertial measurement system is used as a research object, and the residual error after the detection light is stabilized is located on the non-ideal linear polarization of the detection light, thereby establishing a method for real-time measurement of the pumping effect of the detection light. The method is based on the steady-state solution of the Bloch equation, and obtains the product term for evaluating the comprehensive influence of power, frequency and polarization degree on the pumping effect of the detection light by combining the polarization information obtained from the amplitude-frequency response and step modulation experiments under different detection light intensities with the real-time output bias. The problem of not quantitatively evaluating the pumping effect caused by the detection light in the past is solved, and a theoretical basis is provided for fundamentally suppressing the adverse influence of the pumping effect of the detection light on the system. At the same time, the problem of low signal-to-noise ratio caused by low detection power in the past can also be changed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention is a flow chart of a measurement method for detecting optical pumping effect in a SERF inertial measurement system. Figure 1 The method comprises the steps of: 1, starting the SERF atomic spin inertial measurement device, when the gyro works at the "gyro compensation point" (i.e., the inertial measurement system works at the "inertial measurement system compensation point"), testing and recording the gyro steady-state bias signal Vout (i.e., the inertial measurement system steady-state bias signal Vout), and obtaining the scale factor K of the spin inertial measurement device by rotation; and 2, obtaining the Z-axis optical frequency shift L of the gyro by an amplitude-frequency response experiment and a step modulation experiment. z , X-axis optical frequency shift L x , electron relaxation rate Step 3: Change the magnetic field bias B in the Z direction z , continue to measure the amplitude-frequency response, and obtain the electronic polarizability by measuring the slowing factor Get the R under the detection light power m s m (R m is the pumping rate of the detection light, s m Step 4: Change the detection light power I 0 Repeat the above operation (i.e. repeat steps 1 to 3) and bring the obtained parameters into R m s m In the measurement equation, we can get R under different detection light powers. m s m ; Step 5, use the linear least squares fitting method to get R m s m and the detection optical power I 0 The linear relationship between: R m s m =K I I0 +b, using K I The value of determines the magnitude of the detection light pumping effect.

[0020] Figure 2 Schematic diagram of an experimental system for a measurement method for detecting optical pumping effect in a SERF inertial measurement system of the present invention.

[0021] The reference numerals are listed as follows: 1-detection laser; 2-first polarizer (detection liquid crystal module polarizer); 3-detection liquid crystal module; 4-first analyzer (detection liquid crystal module analyzer); 5-first reflector (detection light path reflector); 6-first half-wave plate (detection light path before the half-wave plate in the air chamber); 7-Glan Taylor prism; 8-first quarter-wave plate; 10-first photodetector (detection light path photodetector); 11-magnetic shielding structure / three-dimensional magnetic field coil (the three-dimensional magnetic field coil is arranged in the magnetic shielding structure); 12-oven; 13-air chamber; 14-second half-wave plate (detection light path after the half-wave plate in the air chamber); 15-first polarization beam splitter prism (detection light path polarization beam splitter prism); 16-second photodetector (photodetector 1 of the differential detection module) or third photodetector ( The invention relates to a photodetector 2 of the differential detection module); 17-SERF inertial measurement system output end; 18-pumping laser; 19-first lens (lens 1 of the beam expander lens group); 20-second lens (lens 2 of the beam expander lens group); 21-second reflector (reflector of the pumping light path); 22-second polarizer (polarizer of the pumping light path liquid crystal module); 23-pumping light path liquid crystal module; 24-second analyzer (analyzer of the pumping light path liquid crystal module); 25-third half-wave plate (half-wave plate of the pumping light path); 26-combined prism (a polarization beam splitter prism and a quarter-wave plate are glued together, and the quarter-wave plate faces the air chamber); 27-fourth photodetector (photodetector of the pumping light path); 28-first electric control module (electric control module of the pumping light path); 29-second electric control module (electric control module of the detection light path). DETAILED DESCRIPTION

[0022] Below is the attached figure ( Figure 1-Figure 2 ) and Examples illustrate the present invention.

[0023] Figure 1 The present invention is a flow chart of a measurement method for detecting optical pumping effect in a SERF inertial measurement system. Figure 2 Schematic diagram of the experimental system for the measurement method of detecting the optical pumping effect in the SERF inertial measurement system of the present invention. Figure 1 to Figure 2A measurement method for detecting optical pumping effect in a SERF inertial measurement system comprises the following steps: Step 1, heating the alkali metal gas chamber of the SERF inertial measurement system to the working temperature, and when the laser polarizes the atoms to a steady state, using the magnetic field cross-modulation compensation technology to compensate the magnetic field, at which time the inertial measurement system works at the "inertial measurement system compensation point", and testing and recording the steady-state bias signal V of the inertial measurement system out , the rotation inertial measurement system obtains the scale factor K of the spin inertial measurement device; step 2, through the amplitude-frequency response experiment: apply a series of sinusoidal signals of different frequencies on the X-axis, record the peak-to-peak value of the system output, and perform fitting; and the step modulation experiment: continuously change the voltage of the Z-axis coil to change the magnetic field received by the system on the Z-axis, obtain the value of the system output, and perform fitting. Through the above experimental fitting, the Z-axis optical frequency shift L of the inertial measurement system is obtained. z , electron relaxation rate and the X-axis optical frequency shift L x ; Step 3, change the Z-axis magnetic field bias B z , continue the amplitude-frequency response experiment and obtain the electronic resonance peak ω under different magnetic field biases e , fit the magnetic field bias with the electron resonance peak to obtain the slowdown factor Q, and then obtain the electronic polarizability through the slowdown factor Substitute the obtained items into R m s m The measurement equation of the detection light power R is obtained. m s m The measured value of R m s m is a product term, where R m is the pumping rate of the detection light, s m is the circular polarization degree of the detection light; step 4, repeat steps 1 to 3 at different detection light powers to obtain R m s m ; Step 5, use the linear least squares fitting method to get R m s m and the detection optical power I 0 The linear relationship between: R m s m =K I I 0 +b, b is a constant, K I is the slope, according to K I The size of can determine the size of the detection light pumping effect in the current SERF inertial measurement system. The detection light pumping effect is a component of the residual error after the detection light stabilizes the light intensity, which is produced by the depolarization of the spherical gas chamber and the circular dichroic absorption of the gas, and affects the steady-state output of the inertial measurement system.

[0024] After the detection light is emitted from the detection laser 1, it passes through the first polarizer 2, the detection liquid crystal module 3, the first analyzer 4, the first reflector 5, the first half-wave plate 6, the Glan Taylor prism 7, the first quarter-wave plate 8, the air chamber 13, and the second half-wave plate 14 in sequence before reaching the first polarization beam splitter prism 15. The first polarization beam splitter prism 15 is respectively connected to the second photodetector and the third photodetector 16. The second photodetector and the third photodetector 16 are both connected to the output end 17 of the SERF inertial measurement system. The Glan Taylor prism 7 is connected to the detection liquid crystal module 3 through the first photodetector 10 and the second electric control module 29 in turn. The periphery of the air chamber 13 is provided with an oven 12, a three-dimensional magnetic field coil and a magnetic shielding structure 11. The spin inertial measurement device includes a pumping laser 18. The pumping light emitted by the pumping laser 18 passes through the first lens 19, the second lens 20, the second reflector 21, the second polarizer 22, the pumping light path liquid crystal module 23, the second analyzer 24, the third half-wave plate 25 and the combined prism 26 in sequence, and then passes through the air chamber 13. The combined prism 26 is connected to the pumping light path liquid crystal module 23 through the fourth photodetector 27 and the first electronic control module 28 in sequence.

[0025] By recording different detection optical powers I 0 The steady-state bias signal V of the inertial measurement system under out , the scale factor K of the inertial measurement system is obtained by rotation, and the Z-axis optical frequency shift L of the inertial measurement system is obtained by amplitude-frequency response experiment and step modulation experiment z , electron relaxation rate The electron polarizability is obtained by measuring the slowing factor Q Substitute into the formula to obtain R under this detection light power m s m , change the detection light power for fitting, and finally get R m s m and the detection optical power I 0 The linear relationship between K I The smaller it is, the smaller the pumping effect of the detection light is.

[0026] A measurement method for detecting optical pumping effect in a SERF inertial measurement system, the implementation method and steps are as follows:

[0027] (1) The alkali metal gas chamber of the atomic inertial measurement system is heated to the operating temperature. When the laser polarizes the atoms to a steady state, the magnetic field is compensated using magnetic field cross-modulation compensation technology. At this time, the inertial measurement system works at the "inertial measurement system compensation point" to test and record the steady-state bias signal V of the inertial measurement system. out , the rotation inertial measurement system obtains the scale factor K of the spin inertial measurement device;

[0028] (2) Through the amplitude-frequency response experiment: a series of sinusoidal signals of different frequencies are applied on the x-axis, the peak-to-peak value of the system output is recorded, and fitting is performed; and the step modulation experiment: the voltage of the Z-axis coil is continuously changed to change the magnetic field received by the system on the Z-axis, the value of the system output is obtained, and fitting is performed. Through the above experimental fitting, the optical frequency shift L of the inertial measurement system on the Z-axis is obtained. z , electron relaxation rate The transverse optical frequency shift L along the X-axis x ;

[0029] (3) Change the magnetic field bias B in the Z direction z , continue to measure the amplitude-frequency response experiment and obtain the electronic resonance peak ω under different magnetic field biases e , fit the magnetic field bias with the electron resonance peak to obtain the slowdown factor Q, and then obtain the electronic polarizability P through the slowdown factor z e , bring the obtained term into R m s m The measurement equation of the detection light power R is obtained. m s m The measured value of R m s m is a product term, where R m is the pumping rate of the detection light, s m To detect the circular polarization of light;

[0030] (4) Repeat steps (1) to (3) at different detection light powers to obtain R at different detection light powers. m s m ;

[0031] (5) Using the linear least squares fitting method, we get R m s m and the detection optical power I 0 The linear relationship between: R m s m =K I I 0 +b, according to K I The size of can be used to determine the size of the detection light pumping effect in the current SERF inertial measurement system.

[0032] The principle of the present invention is that when the atomic spin inertial measurement device operates in a high temperature weak magnetic state, the atoms are in a SERF state. The dynamics of its spin ensemble can be described by a set of Bloch equations, and the electron spin polarization rate P e and nuclear spin polarization P n It can be expressed as

[0033]

[0034]

[0035] Where t is time, Ω is the rotation rate, γ e and γ n are the gyromagnetic ratios of electrons and nuclei, respectively, Q is the slowing factor, B is the ambient remanence, and B e and B n is the magnetic field generated by the electron spin and nuclear spin, L is the total optical frequency shift, and is the spin exchange rate between the electron spin and the nuclear spin, is the electron relaxation rate, is the nuclear spin destruction rate, R p and R m represents the pumping rate of the pumping light and the detection light, s p and m are the photon spin vectors of the pump light and the detection light, respectively.

[0036] When the pump beam is along the z direction and the detection beam is along the x direction, the steady-state solution of the electron spin polarization along the x-axis with the input angular velocity is It can be expressed as:

[0037]

[0038] Among them, δB z is the Z-axis magnetic field B z The change in L x is the optical frequency shift along the X-axis, L z is the optical frequency shift along the Z axis.

[0039] The atomic precession signal is detected using linearly polarized light. The wavelength is 0.5nm detuned from the D2 line of Rb. According to the principle of circular birefringence, the signal will appear as a rotation of the polarization plane, and the rotation angle θ can be expressed as

[0040]

[0041] Where l is the length of the detection light passing through the gas chamber, n is the number density of alkali metal atoms, and r e is the classical electron radius, c is the speed of light, f is the oscillation intensity, and L(v) is the Lorentz line shape associated with the frequency v.

[0042] The polarization beam splitter and two photodetectors can obtain the change of polarization plane as an electrical signal output, which is the final output signal of the atomic spin inertial measurement device. The measurement of the detection optical pump rate is carried out under the condition of zero input angular velocity, and the output signal can be simplified to

[0043]

[0044] Among them, K PD is the light-to-voltage conversion coefficient of the photodiode, I 0 To detect light intensity, K is the measurement scale factor obtained by high-precision turntable calibration and can be expressed as

[0045]

[0046] Combining the above formulas, we can get R m s m Function related to the frequency of the detected optical power

[0047]

[0048] Combined with the measured detection optical power and output signal, combined with the step modulation experiment and amplitude-frequency response, the total optical frequency shift L and electronic polarizability are obtained. Electron relaxation rate By using parameters such as the pumping rate of the current detection light, we can get the pumping effect of the detection light.

[0049] Compared with the prior art, the advantages of the present invention are: solving the problem of quantitative measurement of the detection light pumping effect, clarifying the mechanism analysis of the influence of the detection light pumping effect on the atomic inertial measurement system, overcoming the problems of the existing atomic spin inertial measurement system in detecting the light pumping effect in non-real time and reducing the detection light power, and providing a judgment standard and theoretical basis for fundamentally suppressing the pumping effect of the detection light, so as to improve the stability and sensitivity of the system.

[0050] like Figure 1 As shown, the specific implementation steps of the present invention are as follows:

[0051] (1) The alkali metal gas chamber of the inertial measurement device is heated to the operating temperature, and a circularly polarized pump light is used to polarize the alkali metal electrons. The alkali metal electrons polarize the inert gas nuclei through spin exchange. When the laser polarizes the atoms to a steady state, the magnetic field is compensated by using the magnetic field cross-modulation compensation technology. At this time, the inertial measurement system works at the "inertial measurement system compensation point" to test and record the steady-state bias signal V of the inertial measurement system. out , the rotation inertial measurement system obtains the scale factor K of the spin inertial measurement device;

[0052] The light output by the pumping laser passes through a power stabilization system consisting of a beam expansion lens group, a linear polarizer, a power stabilization actuator, a 1 / 2 wave plate, a polarization beam splitter, a photodetector, and an electronic control unit to achieve closed-loop power control. After that, it is converted into circularly polarized light with a spot diameter equal to the diameter of the gas chamber through an optical isolation product. The alkali metal gas chamber is installed inside the shielding tube and the three-dimensional magnetic field coil. The three-dimensional magnetic field coil consists of an X-direction magnetic field coil, a Y-direction magnetic field coil, and a Z-direction magnetic field coil. The driving voltage in the coil is controlled by a signal generator.

[0053] The light output by the detection laser passes through a power stabilization system composed of a linear polarizer, a power stabilization actuator, a 1 / 2 wave plate, a polarization beam splitter, a photodetector, and an electronic control unit to achieve power closed-loop control and power setting. After that, it passes through a reflector and a 1 / 2 wave plate plus a Land-Taylor prism and is converted into linearly polarized light that passes through an alkali metal gas chamber. After passing through a 1 / 2 wave plate and a PBS prism, it is divided into two beams of light that pass through a differential detector. The differential detector outputs signals to a data recorder.

[0054] (2) Through the amplitude-frequency response experiment: a series of sinusoidal signals of different frequencies are applied on the x-axis, the peak-to-peak value of the system output is recorded, and fitting is performed; and the step modulation experiment: the voltage of the Z-axis coil is continuously changed to change the magnetic field received by the system on the Z-axis, the value of the system output is obtained, and fitting is performed. Through the above experimental fitting, the optical frequency shift L of the inertial measurement system on the Z-axis is obtained. z , electron relaxation rate The transverse optical frequency shift L along the X-axis x ;

[0055] (3) Change the magnetic field bias B in the Z direction z , continue to measure the amplitude-frequency response experiment and obtain the electronic resonance peak ω under different magnetic field biases e , fit the magnetic field bias with the electron resonance peak to obtain the slowdown factor Q, and then obtain the electronic polarizability through the slowdown factor Substitute the obtained items into R m s m The measurement equation of the detection light power R is obtained. m s m The measured value of R m s m is a product term, where R m is the pumping rate of the detection light, s m To detect the circular polarization of light;

[0056] (4) Repeat steps (1) to (3) at different detection light powers to obtain R at different detection light powers. m s m ;

[0057] (5) Using the linear least squares fitting method, we get R m s m and the detection optical power I 0 The linear relationship between: R m s m =K I I 0 +b, according to K I The size of can be used to determine the size of the detection light pumping effect in the current SERF inertial measurement system.

[0058] The contents not described in detail in the specification of the present invention belong to the prior art known to the professional and technical personnel in the field. It is pointed out here that the above description helps those skilled in the art to understand the invention, but does not limit the protection scope of the invention. Any equivalent replacement, modification and / or simplification of the above description without departing from the essence of the invention falls within the protection scope of the invention.

Claims

1. A measurement method for detecting optical pumping effect in a SERF inertial measurement system, characterized in that: The following steps are involved: Step 1: Heat the alkali metal gas chamber of the SERF inertial measurement system to the operating temperature. When the laser polarizes the atoms to a steady state, the magnetic field is compensated using the magnetic field cross-modulation compensation technology. At this time, the inertial measurement system works at the "inertial measurement system compensation point". Test and record the steady-state bias signal V of the inertial measurement system. out , the rotation inertial measurement system obtains the scale factor K of the spin inertial measurement device; Step 2: Through the amplitude-frequency response experiment: apply a series of sinusoidal signals of different frequencies on the X-axis, record the peak-to-peak value of the system output, and perform fitting; and the step modulation experiment: continuously change the voltage of the Z-axis coil to change the magnetic field received by the system on the Z-axis, obtain the value of the system output, and perform fitting. Through the above experimental fitting, the optical frequency shift L of the inertial measurement system on the Z-axis is obtained. z , electron relaxation rate and the X-axis optical frequency shift L x ; Step 3: Change the Z-axis magnetic field bias B z , continue the amplitude-frequency response experiment and obtain the electronic resonance peak ω under different magnetic field biases e , fit the magnetic field bias with the electron resonance peak to obtain the slowdown factor Q, and then obtain the electronic polarizability through the slowdown factor Thus, R is obtained under the detection light power m s m The measured value of R m s m is a product term, where R m is the pumping rate of the detection light, s m To detect the circular polarization of light; Step 4: Repeat steps 1 to 3 at different detection optical powers to obtain R m s m ; Step 5: Use the linear least squares fitting method to obtain R m s m The linear relationship between the detected optical power I0: R m s m =K I I0+b, b is a constant, K I is the slope, according to K I The size of can be used to determine the size of the detection light pumping effect in the current SERF inertial measurement system.

2. The method for measuring optical pumping effect in a SERF inertial measurement system according to claim 1, characterized in that: The detection light pumping effect is a component of the residual error after the detection light is stabilized, which is generated by the depolarization of the spherical gas chamber and the circular dichroic absorption of the gas, and affects the steady-state output of the inertial measurement system.

3. The method for measuring optical pumping effect in a SERF inertial measurement system according to claim 1, characterized in that: After the detection light is emitted from the detection laser, it passes through the first polarizer, the detection liquid crystal module, the first analyzer, the first reflector, the first half-wave plate, the Glan Taylor prism, the first quarter-wave plate, the air chamber, and the second half-wave plate in sequence before reaching the first polarization beam splitter prism. The first polarization beam splitter prism is respectively connected to the second photodetector and the third photodetector, the second photodetector and the third photodetector are both connected to the output end of the SERF inertial measurement system, the Glan Taylor prism is connected to the detection liquid crystal module through the first photodetector and the second electric control module in sequence, and an oven, a three-dimensional magnetic field coil and a magnetic shielding structure are arranged around the air chamber.

4. The method for measuring optical pumping effect in a SERF inertial measurement system according to claim 1, characterized in that: The spin inertial measurement device includes a pumping laser. The pumping light emitted by the pumping laser passes through a first lens, a second lens, a second reflector, a second polarizer, a pumping light path liquid crystal module, a second analyzer, a third half-wave plate and a combined prism in sequence, and then passes through an air chamber. The combined prism is connected to the pumping light path liquid crystal module through a fourth photodetector and a first electric control module in sequence.

5. The method for measuring optical pumping effect in a SERF inertial measurement system according to claim 1, characterized in that: By recording the steady-state bias signal V of the inertial measurement system under different detection light powers I0 out , the scale factor K of the inertial measurement system is obtained by rotation, and the Z-axis optical frequency shift L of the inertial measurement system is obtained by amplitude-frequency response experiment and step modulation experiment z , electron relaxation rate The electron polarizability is obtained by measuring the slowing factor Q Thus, R under this detection light power is obtained m s m , change the detection light power for fitting, and finally get R m s m Linear relationship with the detection optical power I0.

6. The method for measuring optical pumping effect in a SERF inertial measurement system according to claim 1, characterized in that: K I The smaller it is, the smaller the pumping effect of the detection light is.

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