Raman light parallelism adjusting system and method for atom interferometer

Abstract

The invention belongs to the technical field of photoelectric servo control, and particularly relates to a Raman light parallelism adjusting system and method for an atom interferometer. Comprising an atom preparation unit, a first Raman light unit, a second Raman light unit, a fluorescence detection unit and an upper computer, and the atom preparation unit is used for preparation and directional projection of cold atomic groups; the first Raman light unit is used for generating beam-expanded Raman laser, the beam-expanded Raman laser and the cold atomic group are subjected to multiple internal state interference effects in the same laser light path, the internal state population of the cold atomic group is changed, and the first Raman light unit has a two-degree-of-freedom light path adjusting function; the second Raman light unit is located below the first Raman light unit and is used for generating another beam-expanded Raman laser, the beam-expanded Raman laser and the cold atomic group are subjected to multiple internal state interference effects in the same laser light path, the internal state population of the cold atomic group is changed, and the second Raman light unit has a four-degree-of-freedom light path adjusting function; the fluorescence detection unit is used for measuring the number of atoms with different internal states; and the upper computer is used for atomic contrast calculation and optical path adjustment control.

Description

Technical Field

[0001] The present invention belongs to the technical field of photoelectric servo control, and in particular relates to a Raman light parallelism adjustment system and an adjustment method for an atom interferometer. Background Art

[0002] Atom interferometers require the combined action of multiple sets of bidirectional (or reverse) Raman beams to achieve high-precision measurements. The angular consistency between the Raman beams directly affects the interference fringe contrast of the atom interferometer, which further affects the output phase accuracy and limits the system's measurement accuracy. Current methods for calibrating the Raman light incident angle for atom interferometers are sometimes only applicable to single-beam Raman light calibration and cannot effectively adjust the relative parallelism of multiple Raman beam combinations, resulting in errors during high-precision alignment. Other methods rely on the size and precision of 90° Raman light reflection prisms, which cannot meet the requirements for Raman light parallelism alignment in atom interferometers with large interference loops spaced far apart. Summary of the Invention

[0003] Purpose of the invention: To provide a Raman light parallelism adjustment system and adjustment method for an atom interferometer, thereby improving the parallelism of Raman light and return light, improving the contrast of the atom interferometer, and thus improving the measurement accuracy.

[0004] Technical solution:

[0005] A Raman light parallelism adjustment system for an atom interferometer includes: an atom preparation unit 1, a first Raman light unit 2, a second Raman light unit 3, a fluorescence detection unit 4, and a host computer 5, wherein:

[0006] Atom preparation unit 1 is used for the preparation and directional ejection of cold atomic clusters;

[0007] The first Raman optical unit 2 is used to generate a beam-expanded Raman laser, which generates multiple internal-state interference interactions with the cold atomic clusters in the same laser optical path, thereby changing the internal-state population of the cold atomic clusters and having a two-degree-of-freedom optical path adjustment function;

[0008] The second Raman optical unit 3 is located below the first Raman optical unit 2 and is used to generate another beam-expanded Raman laser. It generates multiple internal state interference interactions with the cold atomic clusters in the same laser optical path, changes the internal state population of the cold atomic clusters, and has a 4-degree-of-freedom optical path adjustment function.

[0009] The fluorescence detection unit 4 is used to measure the number of atoms in different internal states;

[0010] The host computer 5 is used for atomic contrast calculation and optical path adjustment control.

[0011] Furthermore, the atom preparation unit 1 includes a vacuum chamber 11 and a magneto-optical trap 12 , wherein the magneto-optical trap 12 is located at the bottom of the vacuum chamber 11 , and the magneto-optical trap 12 realizes cooling, trapping and directional ejection of metal atom clusters.

[0012] Furthermore, the first Raman light unit includes: a first Raman light 21, a first quarter-wave plate 22, a first reflector 23, a first Raman return light 24 and a first piezoelectric displacement stage 25, wherein the first Raman light 21 is incident from one side of the atomic preparation unit 1, the first quarter-wave plate 22, the first reflector 23, and the first piezoelectric displacement stage 25 are sequentially located on the other side of the atomic preparation unit 1, the first piezoelectric displacement stage 25 is fixedly connected to the first reflector 23, the frequency composition of the first Raman light 21 is f1 and f2, both frequencies f1 and f2 are negatively detuned from the resonant transition frequency, |f2-f1| is the atomic ground state energy level spacing, and the polarization state of the first Raman light 21 is σ+ circular polarization; the first Raman return light 24 is obtained by the first Raman light 21 passing through the first quarter-wave plate 22, the first reflector 23, and the first quarter-wave plate 22 again, and the polarization state is changed to σ- circular polarization.

[0013] Furthermore, the second Raman light unit includes a second Raman light 31, a second quarter-wave plate 32, a second reflector 33, a second piezoelectric displacement stage 34, a second Raman return light 35 and a third piezoelectric displacement stage 36, wherein the second Raman light 31 is incident from one side of the atom preparation unit 1, the second piezoelectric displacement stage 34 is located on one side of the atom preparation unit 1, the second quarter-wave plate 32, the second reflector 33, and the third piezoelectric displacement stage 36 are located on the other side of the atom preparation unit 1 in sequence, the second piezoelectric displacement stage 34 is fixedly connected to the emission device of the second Raman light 31, and the third piezoelectric displacement stage 36 is fixedly connected to the second reflector 33.

[0014] The frequency composition of the second Raman light 31 is f1 and f2. Both frequencies f1 and f2 are negatively detuned from the resonant transition frequency. |f2-f1| is the atomic ground state energy level spacing. The polarization state of the second Raman light 31 is σ+ circular polarization. The second Raman return light 35 is obtained by the second Raman light 31 passing through the second quarter wave plate 32, the second reflector 33, and the second quarter wave plate 32 again. At the same time, the polarization state changes to σ- circular polarization.

[0015] The first piezoelectric displacement stage 25 , the second piezoelectric displacement stage 34 and the third piezoelectric displacement stage 36 respectively adjust the orthogonal degrees of freedom of the first Raman return light 24 , the second Raman return light 31 and the second Raman return light 35 .

[0016] A method for adjusting the parallelism of Raman light for an atom interferometer is implemented with the aid of the above-mentioned Raman light parallelism adjustment system for an atom interferometer. The method achieves parallel adjustment of a first Raman light 21, a first Raman return light 24, a second Raman light 31, and a second Raman return light 35 by completing coarse alignment through two-pulse interference, and includes: a first self-alignment S11, a second self-alignment S12, a vertical mutual alignment S13, and a horizontal mutual alignment S14.

[0017] Furthermore, S11 is the first self-alignment, specifically:

[0018] Perform multiple atom ejection processes: In each ejection process, perform a single reverse Raman pulse interferometry consisting of a single atomic flyby of the first Raman light 21 and the first Raman return light 24, and perform a scanning Raman light phase φ in the multiple atom ejection processes. laser The atomic interference fringe contrast K1 is obtained by adjusting the first piezoelectric displacement stage 25 until the atomic interference fringe contrast reaches the maximum value K1. max The first piezoelectric displacement stage 25 is fixed in position.

[0019] Furthermore, S12 is the second self-alignment, specifically:

[0020] Perform multiple atom ejection processes: perform single reverse Raman pulse interferometry measurement of the second Raman light 31 and the second Raman return light 35 composed of a single atom flying through the second Raman light 31 in one ejection process, and scan the Raman light phase φ in multiple atom ejection processes. laser The atomic interference fringe contrast K2 is obtained by adjusting the third piezoelectric displacement stage 36 until the atomic interference fringe contrast reaches the maximum value K2 max The third piezoelectric displacement stage 36 is fixed at the same time.

[0021] Furthermore, S13 is vertically aligned with each other, specifically:

[0022] In the atomic ejection trajectory, the first Raman interference (rising process) is performed in the second Raman light 31; the second and third Raman interferences are performed in the first Raman light 21, wherein the Raman pulse of the second Raman interference is the rising process, and the Raman pulse of the third Raman interference is the falling process. By scanning the Raman light phase φ during multiple atomic ejections, laser The atomic interference fringe contrast K3 is obtained by this method;

[0023] By adjusting the second piezoelectric displacement stage 34 until the atomic interference fringe contrast reaches a maximum value K3 max When the second piezoelectric displacement stage 34 is fixed;

[0024] The second self-alignment step S12 is performed to achieve the overlap of the second Raman light 31 and the second returning Raman light 35 .

[0025] Furthermore, S14 is aligned in the horizontal direction, specifically:

[0026] During the ascending process of the atomic ejection trajectory, the first and second Raman interferences are performed in the second Raman light 31, and the third and fourth Raman interferences are performed in the first Raman light 21. By scanning the Raman light phase φ during multiple atomic ejections, laser The atomic interference fringe contrast K4 is obtained by this method;

[0027] By adjusting the second piezoelectric displacement stage 34, the atomic interference fringe contrast reaches a maximum value K4 max When the second piezoelectric displacement stage 34 is fixed;

[0028] The second self-alignment step S12 is performed to achieve the overlap of the second Raman light 31 and the second returning Raman light 35 .

[0029] Furthermore, in the first self-alignment process S11 , the type of Raman laser pulse applied is a π pulse.

[0030] Beneficial effects:

[0031] The Raman light parallelism adjustment system for an atom interferometer of the present invention comprises an atom preparation unit, a first Raman light unit, a second Raman light unit, a fluorescence detection unit, and a host computer. The system of the present invention supports a multi-pulse interference process, and through three angle adjustments, the parallelism of the Raman light and the return light is made better than 0.01 mrad. The present invention uses a successive approximation method and the Raman frequency spectrum characteristics of the atomic interference itself to achieve stable and reliable adjustment and high-precision alignment. The adjustment device used does not introduce additional electromagnetic actuators, which helps to maintain the stability of the magnetic field in the atomic interference area. The system has a simple structure, which is conducive to the design of a miniaturized atom interferometer in a compact space. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic diagram of a Raman light parallelism adjustment system for an atom interferometer according to an embodiment of the present invention;

[0033] Among them, there are vacuum cavity 11, magneto-optical trap 12, first Raman light 21, first quarter-wave plate 22, first reflector 23, first Raman return light 24, first piezoelectric displacement stage 25, second Raman light 31, second quarter-wave plate 32, second reflector 33, second piezoelectric displacement stage 34, second Raman return light 35, third piezoelectric displacement stage 36, detection light 41, detector 42, and host computer 5. DETAILED DESCRIPTION

[0034] like Figure 1According to an embodiment of the present invention, a Raman light parallelism adjustment system for an atom interferometer includes: an atom preparation unit 1, a first Raman light unit 2, a second Raman light unit 3, a fluorescence detection unit 4, and a host computer 5, wherein the atom preparation unit 1 is used for the preparation and directional ejection of cold atomic clusters; the first Raman light unit 2 is used to generate a beam-expanded Raman laser, which undergoes multiple internal-state interference effects with the cold atomic clusters in the same laser optical path, changes the internal-state population of the cold atomic clusters, and has a 2-degree-of-freedom optical path adjustment function; the second Raman light unit 3 is located below the first Raman light unit 2, and is used to generate another beam-expanded Raman laser, which undergoes multiple internal-state interference effects with the cold atomic clusters in the same laser optical path, changes the internal-state population of the cold atomic clusters, and has a 4-degree-of-freedom optical path adjustment function; the fluorescence detection unit 4 is used to measure the number of atoms in different internal states; and the host computer 5 is used for atomic contrast calculation and optical path adjustment control.

[0035] By allowing the internal state interference of Raman laser pulses with atomic clusters, the internal state population inversion rate of the atomic clusters can be 100%. Such Raman laser pulses are called π pulses. By allowing the internal state interference of Raman laser pulses with atomic clusters, the internal state population inversion rate of the atomic clusters can be 50%. Such Raman laser pulses are called π / 2 pulses.

[0036] The atom preparation unit 1 includes a vacuum chamber 11 and a magneto-optical trap 12 , wherein the magneto-optical trap 12 is located at the bottom of the vacuum chamber 11 , and the magneto-optical trap 12 realizes cooling, trapping and directional ejection of metal atom clusters.

[0037] The magneto-optical trap 12 generates atomic ejection trajectories with a divergence angle less than 1 mrad.

[0038] The atom is an alkali metal atom.

[0039] The first Raman light unit 2 includes: a first Raman light 21, a first quarter-wave plate 22, a first reflector 23, a first Raman return light 24 and a first piezoelectric displacement stage 25, wherein the first Raman light 21 is incident from one side of the atom preparation unit 1, the first quarter-wave plate 22, the first reflector 23 and the first piezoelectric displacement stage 25 are sequentially located on the other side of the atom preparation unit 1, the first piezoelectric displacement stage 25 is fixedly connected to the first reflector 23, the frequency composition of the first Raman light 21 is f1 and f2, both frequencies f1 and f2 are negatively detuned from the resonant transition frequency, |f2-f1| is the atomic ground state energy level spacing, and the polarization state of the first Raman light 21 is σ+ circular polarization; the first Raman return light 24 is obtained by the first Raman light 21 passing through the first quarter-wave plate 22, the first reflector 23, and the first quarter-wave plate 22 again, and the polarization state is changed to σ- circular polarization.

[0040] The negative detuning of the resonant transition frequency of the first Raman light 21 is preferably 0.5-2 GHz.

[0041] The second Raman light unit 3 includes a second Raman light 31, a second quarter-wave plate 32, a second reflector 33, a second piezoelectric displacement stage 34, a second Raman return light 35 and a third piezoelectric displacement stage 36, wherein the second Raman light 31 is incident from one side of the atom preparation unit 1, the second piezoelectric displacement stage 34 is located on one side of the atom preparation unit 1, the second quarter-wave plate 32, the second reflector 33 and the third piezoelectric displacement stage 36 are located in sequence on the other side of the atom preparation unit 1, the second piezoelectric displacement stage 34 is fixedly connected to the emission device of the second Raman light 31, and the third piezoelectric displacement stage 36 is fixedly connected to the second reflector 33;

[0042] The second Raman light 31 has a frequency composition of f3 and f4, and both frequencies f3 and f4 are negatively detuned from the resonant transition frequency. |f4-f3| is the atomic ground state energy level spacing, and the polarization state of the second Raman light 31 is σ+ circular polarization. The second Raman return light 35 is obtained by the second Raman light 31 passing through the second quarter-wave plate 32, the second reflector 33, and the second quarter-wave plate 32 again. At the same time, the polarization state changes to σ- circular polarization.

[0043] The first piezoelectric displacement stage 25 , the second piezoelectric displacement stage 34 and the third piezoelectric displacement stage 36 respectively adjust the orthogonal degrees of freedom of the first Raman return light 24 , the second Raman return light 31 and the second Raman return light 35 .

[0044] Preferably, the adjustment step is better than 1 μrad, more preferably 0.4 μrad.

[0045] The fluorescence detection unit 4 includes a detection light 41 and a detector 42, wherein the detection light 41 is a parallel laser beam, and the laser frequency is equal to the resonant excitation transition frequency of the outer electrons of the atom. The detector 42 detects the fluorescence signal intensity I of the different internal state atoms flying through the detection light 41 area. a (t) and I b (t), calculate the probability P that the atom is in state a a =∫I a (t) / (∫I a (t)+∫I b (t)). Further, by scanning the corresponding Raman light phase φ during multiple atomic ejections laser The interference fringes P are obtained by a (φ laser ), the difference between the maximum and minimum values of the interference fringes is the fringe contrast.

[0046] A method for adjusting the parallelism of Raman light for an atom interferometer, the method being performed by means of the above-mentioned system for adjusting the parallelism of Raman light for an atom interferometer, the method comprising:

[0047] Through the first self-alignment S11 , the second self-alignment S12 , the vertical mutual alignment S13 and the horizontal mutual alignment S14 , the parallel adjustment of the first Raman light 21 , the first Raman return light 24 , the second Raman light 31 and the second Raman return light 35 is achieved.

[0048] Among them, S11 is the first self-alignment, and multiple atomic ejection processes are performed: in each ejection process, a single reverse Raman pulse interferometry consisting of a single atomic single-flyover first Raman light 21 and a first Raman return light 24 is performed, and the Raman light phase φ is scanned during multiple atomic ejections. laser The atomic interference fringe contrast K1 is obtained by adjusting the first piezoelectric displacement stage 25 to scan the horizontal direction of the first Raman return light 24. i1 and vertical emission angle θ j1 , record the atomic interference fringe contrast K1(θ i1 ,θ j1 ). Fix the first piezoelectric displacement stage 25 when the atomic interference fringe contrast reaches the maximum value K1 max At this time, the first Raman return light 24 and the first Raman light 21 are in an overlapping (parallel) state.

[0049] S12: Second self-alignment, multiple atom ejection process: Through a single reverse Raman pulse interferometry measurement composed of a single atom flying over the second Raman light 31 and the second Raman return light 35 in one ejection process, the Raman laser pulse type applied is π pulse. By scanning the Raman light phase φ during multiple atom ejection laser The atomic interference fringe contrast K2 is obtained in this way.

[0050] The horizontal emission angle θ of the second Raman return light 35 is scanned by adjusting the third piezoelectric displacement stage 36. i2 and vertical emission angle θ j2 , record the atomic interference fringe contrast K2(θ i2 ,θ j2 ). Fix the third piezoelectric displacement stage 36 when the atomic interference fringe contrast reaches the maximum value K2 max At this time, the second Raman return light 35 and the second Raman light 31 are in an overlapping (parallel) state.

[0051] On the premise of achieving self-alignment of the two Raman beams, mutual alignment is further achieved through multiple pulse interferometry measurements. The specific method is:

[0052] S13 is vertically aligned. After completing S11 self-alignment and S12 second self-alignment, in the atomic ejection trajectory, the first Raman interference is performed in the second Raman light 31 (rising process), wherein the Raman pulse is a π / 2 pulse; the second and third Raman interferences are performed in the first Raman light 21, wherein the Raman pulse of the second Raman interference is a π pulse (rising process), and the Raman pulse of the third Raman interference is a π / 2 pulse (falling process). By scanning the Raman light phase φ during multiple atomic ejections laser The atomic interference fringe contrast K3 is obtained by adjusting the second piezoelectric displacement stage 34 to scan the vertical direction emission angle θ of the second Raman light 31. j3 , record the atomic interference fringe contrast K3(θ j3 ). Fix the vertical emission angle θ of the second Raman light 31 j3* The maximum value K3 appears when the atomic interference fringe contrast max At this time, the vertical angle between the second Raman light 35 and the first Raman light 31 is the smallest. At the same time, the second self-alignment step S12 is performed to achieve the overlap of the second Raman light 31 and the second return Raman light 35.

[0053] S14 is horizontally aligned. After completing S13 vertically aligned, in the atomic ejection trajectory (ascending), the first and second Raman interferences are performed in the second Raman light 31, wherein the Raman pulses are π / 2 pulses and π / 2 pulses respectively. The third and fourth Raman interferences are performed in the first Raman light 21, wherein the Raman pulses are π / 2 pulses and π / 2 pulses respectively. By scanning the Raman light phase φ during multiple atomic ejections, laser The atomic interference fringe contrast K4 is obtained by adjusting the second piezoelectric displacement stage 34 to scan the horizontal emission angle θ of the second Raman light 31. i4 , record the atomic interference fringe contrast K4(θ i4 ). Fix the horizontal emission angle θ of the second Raman light 31 i4* The maximum value K4 appears when the atomic interference fringe contrast max When the horizontal angle between the second Raman light 35 and the first Raman light 31 is the smallest, the second self-alignment step S12 is performed to achieve the overlap of the second Raman light 31 and the second return Raman light 35.

[0054] After the above-mentioned parallelism adjustment is completed, atomic interferometry can be used for angular velocity measurement. The specific interference process is:

[0055] At the atom upward trajectory r1, a Raman laser π / 2 pulse interference is performed in the second Raman light 31, and at the atom upward trajectory r2, a Raman laser π pulse interference is performed in the first Raman light 21; at the atom falling trajectory r3, a Raman laser π pulse interference is performed in the first Raman light 21, and at the atom falling trajectory r4, a Raman laser π / 2 pulse interference is performed in the second Raman light 31. Among them, r1 and r4 are located in the second Raman light 31 area, and r2 and r3 are located in the first Raman light 21 area. Based on the parallelism alignment method provided by S11-S14, the atomic interference angular velocity measurement result can be expressed by the formula Δφ=4Ω·k eff ·g·T 3 Here, Δφ is the atomic interference fringe measurement result, Ω is the carrier angular velocity, and k eff is the Raman laser wave vector, and g is the acceleration due to gravity.

[0056] In summary, the present invention supports a multi-pulse interferometer system, achieving parallelism of Raman and return light better than 0.01 mrad through multiple angle adjustments. This method utilizes the Raman frequency spectrum inherent in atomic interferometry through successive approximation to improve parallelism and enhance the contrast of the atom interferometer. The adjustment is stable and reliable, thereby enhancing measurement accuracy.

[0057] The present application proposes an atomic interferometer Raman light parallelism adjustment system and adjustment method based on atomic interference contrast evaluation, which, based on the physical properties of the atom interferometer itself, has the advantages of high adjustment accuracy and large degree of freedom.

Claims

1. A Raman light parallelism adjustment system for an atom interferometer, characterized in that: The invention comprises: an atom preparation unit (1), a first Raman light unit (2), a second Raman light unit (3), a fluorescence detection unit (4), and a host computer (5), wherein: The atomic preparation unit (1) is used for the preparation and directional ejection of cold atomic clusters; The first Raman light unit (2) is used to generate a beam-expanded Raman laser, and generates multiple internal state interference effects with the cold atomic cluster in the same laser optical path, thereby changing the internal state population of the cold atomic cluster and having a two-degree-of-freedom optical path adjustment function; The second Raman light unit (3) is located below the first Raman light unit (2) and is used to generate another beam-expanded Raman laser, which generates multiple internal state interference effects with the cold atomic cluster in the same laser light path, changes the internal state population of the cold atomic cluster, and has a 4-degree-of-freedom optical path adjustment function; The fluorescence detection unit (4) is used to measure the number of atoms in different internal states; The host computer (5) is used for atomic contrast calculation and optical path adjustment control.

2. The system according to claim 1, wherein: The atom preparation unit (1) comprises a vacuum chamber (11) and a magneto-optical trap (12), wherein the magneto-optical trap (12) is located at the bottom of the vacuum chamber (11), and the magneto-optical trap (12) realizes cooling, trapping and directional ejection of metal atom clusters.

3. The system according to claim 2, characterized in that The first Raman light unit comprises: a first Raman light (21), a first quarter wave plate (22), a first reflector (23), a first Raman return light (24) and a first piezoelectric displacement stage (25), wherein the first Raman light (21) is incident from one side of the atom preparation unit (1), the first quarter wave plate (22), the first reflector (23) and the first piezoelectric displacement stage (25) are sequentially located on the other side of the atom preparation unit (1), and the first piezoelectric displacement stage (25) is fixedly connected to the first reflector. The first Raman light (21) has a frequency composition of f1 and f2, and both frequencies f1 and f2 are negatively detuned from the resonant transition frequency. |f2-f1| is the atomic ground state energy level spacing, and the polarization state of the first Raman light (21) is σ+ circular polarization. The first Raman return light (24) is obtained by the first Raman light (21) passing through the first quarter wave plate (22), the first reflector (23), and the first quarter wave plate (22) again, and the polarization state is changed to σ- circular polarization.

4. The system according to claim 3, characterized in that The second Raman light unit comprises a second Raman light (31), a second quarter-wave plate (32), a second reflector (33), a second piezoelectric displacement stage (34), a second Raman return light (35) and a third piezoelectric displacement stage (36), wherein the second Raman light (31) is incident from one side of the atom preparation unit (1), the second piezoelectric displacement stage (34) is located on one side of the atom preparation unit (1), the second quarter-wave plate (32), the second reflector (33) and the third piezoelectric displacement stage (36) are located on the other side of the atom preparation unit (1) in sequence, the second piezoelectric displacement stage (34) is fixedly connected to the emission device of the second Raman light (31), and the third piezoelectric displacement stage (36) is fixedly connected to the second reflector (33). The second Raman light (31) has a frequency composition of f1 and f2, and both frequencies f1 and f2 are negatively detuned from the resonant transition frequency. |f2-f1| is the atomic ground state energy level spacing, and the polarization state of the second Raman light (31) is σ+ circular polarization. The second Raman return light (35) is obtained by the second Raman light (31) passing through the second quarter wave plate (32), the second reflector (33), and the second quarter wave plate (32) again, and the polarization state is changed to σ- circular polarization. The first piezoelectric displacement stage (25), the second piezoelectric displacement stage (34) and the third piezoelectric displacement stage (36) respectively realize orthogonal direction degree of freedom adjustment of the first Raman return light (24), the second Raman light (31) and the third Raman return light (35).

5. A method for adjusting the parallelism of Raman light for an atom interferometer, characterized in that: The method is performed with the aid of a Raman light parallelism adjustment system for an atom interferometer according to any one of claims 1 to 4. The method achieves parallel adjustment of a first Raman light (21), a first Raman return light (24), a second Raman light (31) and a second Raman return light (35) by completing coarse alignment through two-pulse interference, and includes: a first self-alignment S11, a second self-alignment S12, a vertical mutual alignment S13 and a horizontal mutual alignment S14.

6. The method according to claim 5, characterized in that S11 is the first self-alignment, specifically: Perform multiple atom ejection processes: in each ejection process, perform a single reverse Raman pulse interferometry consisting of a single atomic single-fly over the first Raman light (21) and the first Raman return light (24), and perform scanning Raman light phase in the multiple atom ejection processes. The atomic interference fringe contrast K1 is obtained by adjusting the first piezoelectric displacement stage (25) until the atomic interference fringe contrast reaches a maximum value K1. max The first piezoelectric displacement stage (25) is fixed in position.

7. The method according to claim 5, characterized in that S12 second self-alignment, specifically: Perform multiple atom ejection processes: perform single reverse Raman pulse interferometry measurement of the atoms flying over the second Raman light (31) and the second Raman return light (35) in one ejection process, and scan the Raman light phase in multiple atom ejection processes. The atomic interference fringe contrast K2 is obtained by adjusting the third piezoelectric displacement stage (36) until the atomic interference fringe contrast reaches a maximum value K2 max The third piezoelectric displacement stage (36) is fixed at the same time.

8. The method according to claim 5, characterized in that S13 are aligned vertically, specifically: In the atomic ejection trajectory, the first Raman interference is performed in the second Raman light (31); the second and third Raman interferences are performed in the first Raman light (21), wherein the Raman pulse of the second Raman interference is an ascending process, and the Raman pulse of the third Raman interference is a descending process, by scanning the Raman light phase during multiple atomic ejections. The atomic interference fringe contrast K3 is obtained by this method; By adjusting the second piezoelectric displacement stage (34), the atomic interference fringe contrast reaches a maximum value K3 max When the second piezoelectric displacement stage (34) is fixed; The second self-alignment step S12 is performed to achieve the overlap of the second Raman light (31) and the second return Raman light (35).

9. The method according to claim 5, characterized in that S14 horizontal alignment, specifically: During the rising process of the atomic ejection trajectory, the first and second Raman interferences are performed in the second Raman light (31), and the third and fourth Raman interferences are performed in the first Raman light (21). By scanning the Raman light phase during multiple atomic ejections, The atomic interference fringe contrast K4 is obtained by this method; By adjusting the second piezoelectric displacement stage (34), the atomic interference fringe contrast reaches a maximum value K4 max When the second piezoelectric displacement stage (34) is fixed; The second self-alignment step S12 is performed to achieve the overlap of the second Raman light (31) and the second return Raman light (35).

10. The method according to claim 9, characterized in that In the first self-alignment process S11, the type of Raman laser pulse applied is a π pulse.

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