A continuous measurement atom interferometer control method and system

Abstract

This invention belongs to the field of atomic inertial measurement technology and discloses a method and system for controlling a continuous atomic interferometer. The method includes: atoms undergoing N stimulated Raman transitions sequentially, with a time difference of T between each transition, to achieve atomic interference. In the same vacuum cavity, multiple atomic clusters are subjected to atomic interference sequentially. When the Kth atomic cluster undergoes its nth stimulated Raman transition, the (K+1)th atomic cluster shares the Raman laser with it and simultaneously undergoes its first stimulated Raman transition. This ensures that at every moment in the vacuum cavity, an atomic cluster is performing atomic interference. The interferometer output covers the entire operating time of the interferometer, achieving continuous measurement by the atomic interferometer, where n is less than or equal to N.

Description

Technical Field

[0001] This invention belongs to the field of atomic inertial measurement technology and discloses a control method and system for a continuous measurement atomic interferometer. Background Technology

[0002] As a novel quantum sensor, the atomic interferometer can be transformed into an atomic absolute gravimeter, atomic interferometric gyroscope, atomic interferometric accelerometer, etc., depending on the type of interference and system structure. All of these can be sensitive to inertial physical quantities and possess advantages such as ultra-high precision and long lifespan. However, when applied to inertial navigation scenarios, the dead time introduced by the atoms in the atomic interferometer prevents it from achieving truly continuous measurement. This further impacts the real-time performance of the inertial navigation system and increases navigation errors.

[0003] Several schemes exist for eliminating the dead zone in atomic interferometers. One is a gravimeter based on the interleaved interference effect of two-component atoms. This method eliminates the dead zone by using the interference of two components of atoms. However, its optical and electrical systems need to meet the requirements of both types of atoms, effectively doubling the requirements of the optical and electrical systems, greatly increasing the system complexity and reducing the system reliability. Another is a superimposed, dead-zone-free atomic interferometer gyroscope. This system uses two vacuum cavities to achieve two sets of atomic projectile interference. By controlling the interference timing within the two vacuum cavities, atomic interference is always occurring, thus eliminating the dead zone. However, this design requires two vacuum cavities, 24 trapped beams, two configurations of preparation beams, two sets of probe beams, and one Raman laser, significantly increasing the system complexity, making it difficult to implement, and hindering the miniaturization of the device. Summary of the Invention

[0004] Purpose of the invention: To provide a control method and system for a continuously measuring atomic interferometer, eliminating dead time, realizing continuous measurement, broadening the application scenarios of atomic interferometers, and further applying them to inertial navigation scenarios.

[0005] Technical solution:

[0006] A method for controlling a continuously measuring atomic interferometer includes: atoms undergoing N stimulated Raman transitions sequentially, with a time difference of T between each stimulated Raman transition, to achieve atomic interference; multiple atomic clusters undergoing atomic interference sequentially in the same vacuum cavity; when the Kth atomic cluster undergoes the nth stimulated Raman transition, the (K+1)th atomic cluster shares the Raman laser with it and synchronously undergoes the first stimulated Raman transition of the (K+1)th atomic cluster; this ensures that there is an atomic cluster undergoing atomic interference at every moment in the vacuum cavity, and the interferometer output covers the entire working time of the interferometer, achieving continuous measurement of the atomic interferometer, where n is less than or equal to N.

[0007] Furthermore, for a single atomic group, this control method comprises the following steps:

[0008] Step S1: Atom cooling and confinement: The preparation of cold atomic clusters is completed by controlling the MOT coil, cooling light and repump light 1;

[0009] Step S2: Atom state selection of the prepared atomic group: By controlling the blowing light and the state selection electromagnetic field generator, the internal state |F=1,m is prepared. F =0> atomic groups;

[0010] Step S3: For internal states |F=1,m F Atomic interference is achieved by controlling the parameters and timing of the optical system to complete N stimulated Raman transitions.

[0011] Step S4: Perform final state detection on the atomic clusters that have completed atomic interference: By controlling the probe light and repump light 2, obtain the number of atoms in the F=1 and F=2 states, and obtain the population P of atoms in the F=2 state. F＝2 =N2 / (N1+N2), F = population of 2-state atoms, the interference phase satisfies: Where N1 is the number of atoms in the F=1 state, N2 is the number of atoms in the F=2 state, and the interference phase is...

[0012] Furthermore, for any atomic group involved in the interference, a total of N stimulated Raman transitions occur within the vacuum cavity, with a time interval of T between two adjacent stimulated Raman transitions. Therefore, when the atomic group falls freely within the vacuum cavity, the position of each interference is h(N) = g[(N-1)T + T0]. 2 / 2, where T0 is the time taken from the start of the atomic group's fall to the first stimulated Raman transition.

[0013] Let the Kth interfering atomic group have N stimulated Raman transitions at time points {t1, t2, ..., t...} N}, then the time points of the N stimulated Raman transitions of the (K+1)th interfering atomic group are {t1+nT, t2+nT, ..., t N +nT}, and so on, the time points for the N stimulated Raman transitions of the K+m interfering atomic group are {t1+nmT,t2+nmT,…,t}. N In space, when the Kth interfering atomic group is located at h = gt 2 At position / 2, the position of the (K+m)th interfering atomic group is h = g(t - nmT). 2 / 2.

[0014] Further, step S1 specifically includes:

[0015] First, the MOT coil generates a gradient magnetic field. Three sets of cooling light reflectors are located in the six directions of a three-dimensional Cartesian coordinate system, with the center of the light field coinciding with the zero point of the gradient magnetic field. The cooling light in each direction generates a damping force on the oncoming atoms. At the same time, the gradient magnetic field and the polarization of the laser combine to generate a restoring force on the atoms, ultimately trapping the atoms at the center of the light field. Meanwhile, the pump light 1 acts to suppress the light pumping effect, allowing the cooling process to continue.

[0016] Furthermore, step S2 specifically includes:

[0017] After shutting down the MOT coil, cooling light, and repump light used in step S1, atoms in the F=1 state in the atomic cluster are first removed by blowing light. Then, an electromagnetic field that inverts the population is applied at the location of the atomic cluster, making |F=2,m F Atoms with =0> are transferred to F=1,m F =0> energy level, then apply a blown light again to remove the atoms in the F=2 state, and you can obtain pure |F=1,m F =0> state atomic groups, complete step S2.

[0018] Furthermore, step S3 specifically includes:

[0019] By controlling the on-time of the Raman laser, N stimulated Raman transitions are achieved, with the action time sequence being {t1, t2, ..., t...}. N Each time the Raman laser is activated, the activation time τ and the Raman laser intensity I are controlled to achieve a 50% or 100% flip of the atomic internal state. This is achieved by configuring the action time sequence {t1,t2,…,t…}. N}, τ, and I are used to achieve different types of atomic interference and measure different physical quantities.

[0020] Furthermore, step S4 specifically includes:

[0021] Atoms in the F=2 state are detected using a probe light, and the fluorescence generated by the probe is collected by a photodetector, outputting a corresponding fluorescence signal. The intensity of this fluorescence signal is linearly related to the number of atoms in the F=2 state. Atoms in the F=1 state are then detected using a repump light 2 and a probe light, and their fluorescence signals are recorded by a photodetector. The intensity of this fluorescence signal is linearly related to the number of atoms in the F=2 state, thus realizing the detection of the number of atoms in the dual-state.

[0022] A continuous measurement atomic interferometer control system is disclosed. The system is a vacuum cavity comprising an atomic preparation region, an atomic interferometry region, and an atomic detection region. The atomic preparation region includes a MOT coil, a repump beam 1, a cooling beam, three sets of cooling beam mirrors, a diffuser beam, and a selective electromagnetic field generator. The MOT coil, cooling beam, and three sets of cooling beam mirrors constitute a magneto-optical trap. The three sets of cooling beam mirrors are located in the six directions of a three-dimensional Cartesian coordinate system. The zero point of the magnetic field strength of the MOT coil coincides with the geometric center of the three sets of mirrors. The repump beam 1 points towards the center of the cooling beam's optical field. The selective electromagnetic field generator and the diffuser beam are located at the bottom of the atomic preparation region.

[0023] The atomic interference region includes a Raman laser, a Raman laser mirror, and a quarter-wave plate. The Raman laser mirror and quarter-wave plate are used to generate a pair of Raman lasers for inverse Raman transitions. The Raman laser is located at the top of the entire vacuum cavity, with its direction aligned with gravity. The Raman laser mirror is located at the bottom of the entire vacuum cavity, with its surface perpendicular to the Raman light direction. The quarter-wave plate is located directly above the Raman laser mirror.

[0024] The atomic detection region includes a probe light, a probe light reflector, a repump light 2, and a photodetector. The probe light is located at the top of the atomic detection region and is split into two beams, with the direction of the light perpendicular to the direction of gravity. The repump light 2 is located in the middle of the two probe light beams and is parallel to the probe light. The probe light reflector and the photodetector are located on the opposite side of the probe light.

[0025] The atom preparation region is located at the top of the vacuum cavity. After completing steps S1 and S2, the atom cluster is released and begins to fall freely into the atom interference region. The Raman laser used in the interference region coincides with the trajectory of the free fall of the atom cluster. After completing step S3, when the atom cluster reaches the atom detection region, step S4 is completed.

[0026] Beneficial effects:

[0027] 1. This invention controls the timing of the atomic interferometer, allowing the atomic clusters interfering before and after to share the Raman laser, thereby eliminating the dead zone of the atomic interferometer and enabling continuous measurement. This allows the atomic interferometer to be better used as an inertial sensor in the field of inertial navigation.

[0028] 2. The system complexity of this invention is not significantly increased compared to the traditional atomic interferometer gravimeter scheme. Only the timing of each sub-module of the system needs to be reconfigured to achieve continuous absolute gravity measurement. Compared with other existing dead zone elimination schemes, it has a simpler system and control scheme. Attached Figure Description

[0029] Figure 1 A flowchart of the continuous measurement atomic interferometer provided by the present invention;

[0030] Figure 2 A schematic diagram of the control timing for each controlled object in a continuous measurement atomic interferometer control method provided by the present invention;

[0031] Figure 3 A schematic diagram showing the relationship between the position of atomic clusters and time during the operation of the dual-pulse continuous measurement atomic interferometer provided by the present invention;

[0032] Figure 4 This is a schematic diagram showing the relationship between the position of atomic clusters and time during the operation of the three-pulse continuous measurement atomic interferometer provided by the present invention. Detailed Implementation

[0033] Compared to traditional atomic interferometers, this invention improves the timing efficiency of the atomic interferometer by synchronizing the atomic cooling and trapping and state preparation steps with the atomic interferometry steps. When the Kth atomic group undergoes the nth stimulated Raman transition, the (K+1)th atomic group shares the Raman laser with it, and the (K+1)th atomic group undergoes its first stimulated Raman transition simultaneously.

[0034] This invention provides a control system for a continuous measurement atomic interferometer gravimeter. The system is a vacuum chamber, which includes an atomic preparation region, an atomic interferometry region, and an atomic detection region.

[0035] The vacuum chamber is filled with alkali metal vapor, and the atomic clusters remain inside the vacuum chamber throughout the entire gravity measurement process.

[0036] The atom preparation region includes a MOT coil, repump light 1, cooling light, three sets of cooling light mirrors, a blow-off light, and a state-selective electromagnetic field generator. The MOT coil, cooling light, and three sets of cooling light mirrors constitute a magneto-optical trap. The three sets of cooling light mirrors are located in the six directions of a three-dimensional Cartesian coordinate system. The zero point of the magnetic field strength of the MOT coil coincides with the geometric center of the three sets of mirrors. The damping force generated by the cooling light on the oncoming atoms, and the restoring force generated by the combination of the gradient magnetic field and the polarization of the laser, ultimately trap the atoms at the center of the magneto-optical trap. Simultaneously activating repump light 1 during cooling increases the number of atoms trapped. After atom trapping, the cooling light, repump light 1, and MOT coil are turned off, and the atoms fall freely. After passing through the blow-off light and the state-selective electromagnetic field generator, the internal state is obtained where all atoms are in the state |F=1,m. F=0> state atomic clusters. The MOT coil is a pair of anti-Helmholtz coils that generate a gradient magnetic field, with the magnetic field strength increasing the further away from the center. The cooling light is a negatively detuned circularly polarized light that transitions atoms to excited states. The combined effect of these two technologies achieves the cooling and confinement of atoms. The state-selective electromagnetic field generator can produce an electromagnetic field with a frequency difference between F=1 and F=2, which can achieve periodic changes in the atomic population. By controlling the duration of this change, the internal state changes of atoms can be achieved. Repump lights 1 and 2 are lasers that excite F=1 state atoms to higher energy levels. During their operation, atoms that fall back to the F=1 state from the excited state will be re-excited, ultimately resulting in all ground state atoms being in the F=2 state. The scattering light is a laser that transitions F=1 and F=2 atoms to excited states. According to the law of conservation of momentum, it can change the trajectory of F=1 or F=2 atoms, causing them to deviate from their original trajectories.

[0037] The atomic interference region includes a Raman laser, a Raman laser mirror, and a quarter-wave plate. The Raman laser mirror and quarter-wave plate are used to generate a pair of Raman lasers for inverse Raman transitions. Inverse Raman transitions refer to the two Raman laser wave vectors sensed by the atom having opposite directions. Under this condition, the total Raman laser wave vector is larger, and the phase obtained from the interference is more sensitive to gravitational acceleration. By controlling the on-time of the Raman laser, π / 2 and π-length pulsed Raman lasers can be achieved, ultimately realizing the "beam splitting-reflection-recombining" of the atomic cluster. Raman lasers can achieve periodic changes in the atomic population and simultaneously change atomic momentum. By controlling its on-time, π / 2 pulsed Raman lasers and π pulsed Raman lasers can be achieved. Both π / 2 pulsed Raman lasers and π pulsed Raman lasers can achieve changes in the internal state and momentum of atoms. The difference between π pulsed Raman lasers and π / 2 pulsed Raman lasers lies in their intensity or duration.

[0038] Under ideal conditions, a π / 2 pulsed Raman laser can convert atoms in the F=1 state (or F=2 state) into 50% F=1 state and 50% F=2 state. The momentum of the atoms whose internal states have changed also changes, and their trajectories will be deflected. The effect is similar to a beam splitter in optics, which can achieve "beam splitting" or "beam combining".

[0039] Under ideal conditions, a π-pulse Raman laser can completely convert atoms in the F=1 (or F=2) state into atoms in the F=2 (or F=1) state. At the same time, the momentum also changes, and the trajectory of the entire atomic group is deflected. The effect is analogous to a mirror in optics, which can achieve "reflection".

[0040] The atom detection region includes a probe light, a probe light reflector, a repump light, and a photodetector. The probe light first detects atoms in the F=2 state. The probe light reflector generates a reverse probe light to prevent the atomic trajectories from being deflected by the probe light. The fluorescence generated by the probe is collected by the photodetector, outputting the corresponding fluorescence signal. Then, atoms in the F=1 state are detected by the repump light and probe light, and their fluorescence signals are recorded by the photodetector, yielding the atomic interference result. The probe light can excite F=2 state atoms to higher energy levels. The absorption of the probe light by the atoms causes a change in the intensity of the probe light; this change can be used to determine the number of F=2 state atoms.

[0041] The repump beams 1 and 2 are lasers that excite F=1 state atoms to a higher energy level. During their operation, atoms that fall back to the F=1 state from the excited state will be excited again, and finally all ground state atoms will be in the F=2 state.

[0042] like Figure 1 and 2 As shown, the present invention provides a method for controlling a continuous atomic interferometer, comprising: atoms undergoing N stimulated Raman transitions sequentially, with a time difference of T between each stimulated Raman transition, thereby achieving atomic interference; multiple atomic clusters undergoing atomic interference sequentially in the same vacuum cavity; when the Kth atomic cluster undergoes the nth stimulated Raman transition, the (K+1)th atomic cluster shares the Raman laser with it and simultaneously undergoes the first stimulated Raman transition of the (K+1)th atomic cluster; this ensures that there is an atomic cluster undergoing atomic interference at every moment in the vacuum cavity, and the interferometer output covers the entire working time of the interferometer, thereby achieving continuous measurement of the atomic interferometer, wherein n is less than or equal to N.

[0043] For any atomic group involved in the interference, a total of N stimulated Raman transitions occur in the vacuum cavity, with a time interval of T between two adjacent stimulated Raman transitions. Then, when the atomic group falls freely in the vacuum cavity, the position of each interference is h(N) = g[(N-1)T + T0]. 2 / 2, where T0 is the time taken from the start of the atomic group's fall to the first stimulated Raman transition.

[0044] Let the Kth interfering atomic group have N stimulated Raman transitions at time points {t1, t2, ..., t...} N}, then the time points of the N stimulated Raman transitions of the (K+1)th interfering atomic group are {t1+nT, t2+nT, ..., t N +nT}, and so on, the time points for the N stimulated Raman transitions of the K+m interfering atomic group are {t1+nmT,t2+nmT,…,t}. N In space, when the Kth interfering atomic group is located at h = gt 2At position / 2, the position of the (K+m)th interfering atomic group is h = g(t - nmT). 2 / 2.

[0045] For a single atomic group, the control method consists of the following steps:

[0046] Step S1: Atom Cooling and Confinement: The preparation of cold atomic clusters is completed by controlling the MOT coil, cooling light, and repump light 1; Step S1 specifically includes:

[0047] First, the MOT coil generates a gradient magnetic field. Three sets of cooling light reflectors are located in the six directions of a three-dimensional Cartesian coordinate system, with the center of the light field coinciding with the zero point of the gradient magnetic field. The cooling light in each direction generates a damping force on the oncoming atoms. At the same time, the gradient magnetic field and the polarization of the laser combine to generate a restoring force on the atoms, ultimately trapping the atoms at the center of the light field. Meanwhile, the pump light 1 acts to suppress the light pumping effect, allowing the cooling process to continue.

[0048] Step S2: Atom state selection of the prepared atomic group: By controlling the blowing light and the state selection electromagnetic field generator, the internal state |F=1,m is prepared. F =0> atomic groups; step S2 specifically is:

[0049] After shutting down the MOT coil, cooling light, and repump light used in step S1, atoms in the F=1 state in the atomic cluster are first removed by blowing light. Then, an electromagnetic field that inverts the population is applied at the location of the atomic cluster, making |F=2,m F Atoms with =0> are transferred to F=1,m F =0> energy level, then apply a blown light again to remove the atoms in the F=2 state, and you can obtain pure |F=1,m F =0> state atomic groups, complete step S2.

[0050] Step S3: For internal states |F=1,m F Atomic interference is achieved by controlling the optical system parameters and timing to complete N stimulated Raman transitions; step S3 specifically involves:

[0051] By controlling the on-time of the Raman laser, N stimulated Raman transitions are achieved, with the action time sequence being {t1, t2, ..., t...}. N Each time the Raman laser is activated, the activation time τ and the Raman laser intensity I are controlled to achieve a 50% or 100% flip of the atomic internal state. This is achieved by configuring the action time sequence {t1,t2,…,t…}. N}, τ, and I are used to achieve different types of atomic interference and measure different physical quantities.

[0052] Step S4: Perform final state detection on the atomic clusters that have completed atomic interference: By controlling the probe light and repump light 2, obtain the number of atoms in the F=1 and F=2 states, and obtain the population P of atoms in the F=2 state. F＝2 =N2 / (N1+N2), F = population of 2-state atoms, the interference phase satisfies: The interference phase of the atomic group can be obtained using this formula, where N1 is the number of atoms in the F=1 state, N2 is the number of atoms in the F=2 state, and the interference phase is... Step S4 is as follows:

[0053] Atoms in the F=2 state are detected using a probe light, and the fluorescence generated by the probe is collected by a photodetector, outputting a corresponding fluorescence signal. The intensity of this fluorescence signal is linearly related to the number of atoms in the F=2 state. Atoms in the F=1 state are then detected using a repump light 2 and a probe light, and their fluorescence signals are recorded by a photodetector. The intensity of this fluorescence signal is linearly related to the number of atoms in the F=2 state, thus realizing the detection of the number of atoms in the dual-state.

[0054] Example 1

[0055] The atomic interferometer is configured with a total of 3 interference cycles, and the interference sequence is π / 2-π-π / 2. When the Kth atomic group undergoes its 3rd stimulated Raman transition, the (K+1)th atomic group shares the Raman laser with it and simultaneously undergoes its 1st stimulated Raman transition, thus realizing a three-pulse atomic interferometer gravimeter. The schematic diagram of the time-position relationship of the atomic groups is shown below. Figure 4 As shown. The following are the implementation steps.

[0056] S1: Turn on the MOT coil to generate a gradient magnetic field, with the magnetic field strength increasing further away from the center. Turn on the cooling light, aligning the zero point of the magnetic field with the center of the light field. The negatively detuned laser exerts a damping force on the oncoming atoms, and the combination of the gradient magnetic field and the laser polarization generates a restoring force on the atoms, thus creating a potential well at the center, cooling and trapping the atoms there. Simultaneously, turn on repump light 1, re-exciting atoms that have fallen back to the F=1 state during the cooling process, suppressing the optical pumping effect and maintaining the cooling process.

[0057] S2, turn off the cooling light, repump light, and MOT coil. Turn on the blowing light to remove atoms in the F=1 state from the atomic clusters. Control the selected electromagnetic field generator to apply a microwave pulse that reverses the population time length, making |F=2,m F Atoms with =0> are transferred to |F=1,m F =0 energy level, then apply a blown light again to remove the atoms in the F=2 state, and you can obtain pure F=1,m F =0> state atomic groups, completing the state selection of atoms.

[0058] S3 controls the activation and duration of the Raman laser, creating a π / 2-π-π / 2 Raman pulse sequence. The atomic cluster interacts with these three pulses sequentially during its descent. After interacting with the first π / 2 pulse Raman laser, 50% of the prepared F=1 state atomic clusters will transform into F=2 state atoms, and their trajectories will undergo a fixed shift.

[0059] S4, after a free evolution time T, the two-state atomic clusters are simultaneously interacted with the π-pulse Raman laser, causing the internal states of the atoms to flip and their trajectories to deflect at the same angle.

[0060] After a free evolution time T in step S5, the atomic state and trajectory change again after interaction with the second π / 2 pulse Raman laser, thus completing the atomic interference process. Simultaneously, steps S1 and S2 for the next measurement are completed. The position of the atomic cluster at the end of step S2 should be the position where it interacted with the first π / 2 pulse, eliminating the measurement dead zone and enabling continuous measurement.

[0061] S6, after a short time of atomic interference, the atomic cluster reaches the detection region, and the detection light is turned on. First, atoms in the F=2 state are detected, and the fluorescence signal generated by the cluster is collected by the photodetector. Then, through re-pump light 2, atoms in the F=1 state are pumped to the F=2 state, and the detection light is turned on again, completing the detection of atoms in the F=1 state. The resulting fluorescence signal is collected by the photodetector. Finally, the number of atoms in both states is obtained, and the population P of atoms in the F=2 state is calculated. F＝2 =N2 / (N1+N2). Its relationship with gravitational acceleration is P F＝2 =(1-cos((k) eff ·g-α)T 2 )) / 2, k on the right side of the equation eff Let α be the Raman laser wave vector; α be the Raman laser chirp; and T be the free evolution time, which is the time interval between Raman pulses. Since these three are known quantities, the gravitational acceleration value g can be solved.

[0062] Example 2

[0063] The atomic interferometer is configured with a total of 2 interference cycles, and the interference sequence is π / 2-π / 2. When the Kth atomic group undergoes its second stimulated Raman transition, the (K+1)th atomic group shares the Raman laser with it and simultaneously undergoes its first stimulated Raman transition, achieving continuous measurement of the two pulses. The schematic diagram of the time-position relationship of the atomic groups is shown below. Figure 3 As shown. The following are the implementation steps.

[0064] S1: Turn on the MOT coil to generate a gradient magnetic field, with the magnetic field strength increasing further away from the center. Turn on the cooling light, aligning the zero point of the magnetic field with the center of the light field. The negatively detuned laser exerts a damping force on the oncoming atoms, and the combination of the gradient magnetic field and the laser polarization generates a restoring force on the atoms, thus creating a potential well at the center, cooling and trapping the atoms there. Simultaneously, turn on repump light 1, re-exciting atoms that have fallen back to the F=1 state during the cooling process, suppressing the optical pumping effect and maintaining the cooling process.

[0065] S2, turn off the cooling light, repump light, and MOT coil. Turn on the blowing light to remove atoms in the F=1 state from the atomic clusters. Control the selected electromagnetic field generator to apply a microwave pulse that reverses the population time length, making |F=2,m F Atoms with =0> are transferred to |F=1,m F =0 energy level, then apply a blown light again to remove the atoms in the F=2 state, and you can obtain pure F=1,m F =0> state atomic groups, completing the state selection of atoms.

[0066] S3 controls the activation and duration of the Raman laser, creating a π / 2-π / 2 Raman pulse sequence. The atomic cluster interacts with these three pulses sequentially during its descent. After interacting with the first π / 2 pulse Raman laser, 50% of the prepared F=1 state atomic clusters will transform into F=2 state atoms, and their trajectories will undergo a fixed shift.

[0067] After a free evolution time T in step S4, the atomic state and trajectory change again due to interaction with the second π / 2 pulse Raman laser, thus completing the atomic interference process. Simultaneously, steps S1 and S2 for the next measurement are completed. The position of the atomic cluster at the end of step S2 should be the position where it interacted with the first π / 2 pulse, eliminating the measurement dead zone and enabling continuous measurement.

[0068] In step S5, shortly after the atomic interference is complete, the atomic cluster reaches the detection region. The detection light is then activated, initially detecting atoms in the F=2 state. The fluorescence signal generated by the cluster is collected by a photodetector. Next, re-pump light 2 pumps the F=1 state atoms to the F=2 state. The detection light is then activated again, completing the detection of F=1 state atoms. The resulting fluorescence signal is collected by the photodetector. Finally, the number of atoms in both states is obtained, resulting in atomic interference fringes.

Claims

1. A method for controlling a continuously measuring atomic interferometer, characterized in that, include: Atoms undergo N stimulated Raman transitions sequentially, with a time difference of T between each transition, achieving atomic interference. In the same vacuum cavity, multiple atomic clusters are subjected to atomic interference sequentially. When the Kth atomic cluster undergoes its nth stimulated Raman transition, the (K+1)th atomic cluster shares the Raman laser and simultaneously undergoes its first stimulated Raman transition. This ensures that at every moment, an atomic cluster is performing atomic interference in the vacuum cavity. The interferometer output covers the entire operating time of the interferometer, enabling continuous measurement using the atomic interferometer. Here, n is less than or equal to N. For any atomic group involved in the interference, a total of N stimulated Raman transitions occur within the vacuum cavity, with a time interval of T between two adjacent stimulated Raman transitions. Then, when the atomic group falls freely within the vacuum cavity, the position of each interference is... In the formula The time taken for the atomic cluster to begin its descent and undergo its first stimulated Raman transition. Let the Kth interfering atomic group have N stimulated Raman transitions at the following times: Then the time points of the (K+1)th interfering atomic group undergoing N stimulated Raman transitions are respectively And so on, the time points at which the K+m-th interfering atomic group undergoes N stimulated Raman transitions are respectively In space, when the Kth interfering atomic group is located at When the position is determined, the position of the (K+m)th interfering atomic group is: .

2. The method for controlling a continuously measuring atomic interferometer according to claim 1, characterized in that, For a single atomic group, the control method consists of the following steps: Step S1: Atom cooling and confinement: The preparation of cold atomic clusters is completed by controlling the MOT coil, cooling light and repump light 1; Step S2: Atom state selection of the prepared atomic group: By controlling the blowing light and the state selection electromagnetic field generator, the internal state is prepared as follows. atomic groups; Step S3: For internal states of Atomic interference is achieved by controlling the parameters and timing of the optical system to complete N stimulated Raman transitions. Step S4: Perform final state detection on the atomic clusters that have completed atomic interference: By controlling the probe light and repump light 2, obtain the number of atoms in the F=1 and F=2 states, and obtain the population of atoms in the F=2 state. F = 2-state atomic population, the interference phase satisfies: Where N1 is the number of atoms in the F=1 state, N2 is the number of atoms in the F=2 state, and the interference phase is... .

3. The method for controlling a continuously measuring atomic interferometer according to claim 2, characterized in that, Step S1 is as follows: First, the MOT coil generates a gradient magnetic field. Three sets of cooling light reflectors are located in the six directions of a three-dimensional Cartesian coordinate system, with the center of the light field coinciding with the zero point of the gradient magnetic field. The cooling light in each direction generates a damping force on the oncoming atoms. At the same time, the gradient magnetic field and the polarization of the laser combine to generate a restoring force on the atoms, ultimately trapping the atoms at the center of the light field. Meanwhile, the pump light 1 acts to suppress the light pumping effect, allowing the cooling process to continue.

4. The method for controlling a continuously measuring atomic interferometer according to claim 2, characterized in that, Step S2 is as follows: After shutting down the MOT coil, cooling light, and repump light used in step S1, atoms in the F=1 state in the atomic clusters are first removed by blowing light. Then, an electromagnetic field that inverts the population number is applied at the location of the atomic clusters. Atoms transferred to By applying a second wave of diffused light to the energy level and removing atoms in the F=2 state, a pure energy level can be obtained. The atomic groups in the state are then processed, completing step S2.

5. The method for controlling a continuously measuring atomic interferometer according to claim 2, characterized in that, Step S3 is as follows: By controlling the on-time of the Raman laser, N stimulated Raman transitions are achieved, with the action time sequence as follows: Each time the Raman laser is activated, the activation time τ and the Raman laser intensity I are controlled to achieve a 50% or 100% flip of the atomic internal state, by configuring the action time sequence. τ and I are used to achieve different types of atomic interference and measure different physical quantities.

6. The method for controlling a continuously measuring atomic interferometer according to claim 2, characterized in that, Step S4 is as follows: Atoms in the F=2 state are detected using a probe light, and the fluorescence generated by the probe is collected by a photodetector, outputting a corresponding fluorescence signal. The intensity of this fluorescence signal is linearly related to the number of atoms in the F=2 state. Atoms in the F=1 state are then detected using a repump light 2 and a probe light, and their fluorescence signals are recorded by a photodetector. The intensity of this fluorescence signal is linearly related to the number of atoms in the F=2 state, thus realizing the detection of the number of atoms in the dual-state.

7. A control system for a continuously measuring atomic interferometer, characterized in that, The system is a vacuum cavity used to execute the atomic interferometer control method according to any one of claims 2-6. The vacuum cavity includes: an atomic preparation region, an atomic interference region, and an atomic detection region. The atomic preparation region includes a MOT coil, a repump light 1, a cooling light, three sets of cooling light mirrors, a diffused light, and a selective electromagnetic field generator. The MOT coil, cooling light, and three sets of cooling light mirrors constitute a magneto-optical trap. The three sets of cooling light mirrors are located in the six directions of a three-dimensional rectangular coordinate system. The zero point of the magnetic field strength of the MOT coil coincides with the geometric center of the three sets of mirrors. The repump light 1 points towards the center of the cooling light's optical field. The selective electromagnetic field generator and the diffused light are located at the bottom of the atomic preparation region. The atomic interference region includes a Raman laser, a Raman laser mirror, and a quarter-wave plate. The Raman laser mirror and quarter-wave plate are used to generate a pair of Raman lasers for inverse Raman transitions. The Raman laser is located at the top of the entire vacuum cavity, with its direction aligned with gravity. The Raman laser mirror is located at the bottom of the entire vacuum cavity, with its surface perpendicular to the Raman light direction. The quarter-wave plate is located directly above the Raman laser mirror. The atomic detection region includes a probe light, a probe light reflector, a repump light 2, and a photodetector. The probe light is located at the top of the atomic detection region and is split into two beams, with the direction of the light perpendicular to the direction of gravity. The repump light 2 is located between the two probe light beams and is parallel to the probe light. The probe light reflector and the photodetector are located on the opposite side facing the probe light. The atom preparation region is located at the top of the vacuum cavity. After completing steps S1 and S2, the atom cluster is released and begins to fall freely into the atom interference region. The Raman laser used in the interference region coincides with the trajectory of the free fall of the atom cluster. After completing step S3, when the atom cluster reaches the atom detection region, step S4 is completed.

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