Cold atom gravimeter sequential control method and device for controlling speed distribution evolution

Abstract

The invention provides a cold atom gravimeter sequential control method and device for controlling speed distribution evolution, and the method comprises the steps: introducing a radio frequency drive light pulse which is matched with the instantaneous centroid speed and thermal speed distribution in an atom falling process; the atoms with different instantaneous centroid velocities and different thermal velocity distributions are sequentially acted by the radio frequency driving light pulses matched with the atoms, so that the thermal velocity distribution width of the atoms is rapidly reduced, the proportion of the atoms participating in the effective interference or momentum transfer process is effectively improved, the atomic signal contrast and interference fringe visibility are enhanced, and the measurement accuracy is improved. The method has a direct effect on gravity measurement sensitivity and statistical noise reduction.

Description

Technical Field

[0001] This application relates to the field of cold atom gravimeter technology, and in particular to a timing control method and apparatus for cold atom gravimeter that manipulates the evolution of velocity distribution. Background Technology

[0002] Gravitational acceleration is a physical quantity that varies with time and space. Accurate measurement of gravitational acceleration has wide and important applications in fields such as resource exploration, geodesy, and metrology. Cold atom gravimeters are instruments used to obtain absolute gravitational acceleration. Their atoms are composed of alkali metal groups, such as rubidium-87. Before measuring absolute gravitational acceleration, the atomic cloud needs to be cooled. The cooling process includes: first, ultracold atomization is prepared in a vacuum using laser cooling and magneto-optical trap technology; then, the atomic cloud undergoes free fall and Raman cooling during free fall to obtain an atomic cloud suitable for absolute gravitational acceleration measurement.

[0003] The core of Raman cooling is to use Raman lasers with specific frequency differences to selectively transition atoms at different speeds (here, speed refers to the speed dominated by thermal motion inside the atom, denoted as thermal velocity), so that the atoms can achieve a stepwise compression of the thermal velocity distribution width in multiple processes.

[0004] In existing technologies, Raman cooling processes employ pre-set frequency scanning strategies or pulse sequences with fixed time intervals to sequentially select different velocity steps. However, during free fall, atoms' instantaneous velocities (including the velocity corresponding to free fall (denoted as the centroid velocity) and thermal velocities) change continuously over time under the influence of gravity. If a fixed or coarse-grained timing control method is still used, it is impossible to match the motion phase of all atoms. This can easily lead to some velocity components (referring to thermal velocities) not being perfectly excited or transferred due to incorrect timing, resulting in a decrease in the purity of the selected atomic cloud velocity (referring to thermal velocities) and a widening of the velocity (referring to thermal velocities) distribution, thus reducing the accuracy of velocity (referring to thermal velocities) selection and cooling efficiency. At the same time, the widening of the velocity (referring to thermal velocities) and position distribution directly leads to a decrease in the "visibility" of the interference fringes, resulting in a decrease in signal contrast. If the experimental environment changes slowly, the fixed timing control method cannot adapt to such changes to maintain optimal cooling and beam splitting effects. This can cause a slow drift in contrast and the number of atoms, requiring more frequent calibration and reducing signal stability. Summary of the Invention

[0005] This application provides a timing control method and apparatus for a cold atom gravimeter that manipulates the evolution of velocity distribution, in order to solve the technical problems mentioned in the background art.

[0006] In a first aspect, this application provides a timing control method for a cold atom gravimeter that manipulates the evolution of velocity distribution, comprising: Obtain the initial centroid velocity, initial thermal velocity, and target thermal velocity of the atomic cloud; Based on the initial thermal velocity of the atomic cloud, determine the initial thermal velocities of multiple targets; Based on the initial thermal velocity of each target, determine the effective wave vector direction for Raman cooling of each target's initial thermal velocity; The pulse application time corresponding to the initial thermal velocity of each target is obtained. The pulse application time corresponding to the initial thermal velocity of each target is determined by the pulse application time, pulse time, and pulse interval of the previous pulse, or it is the pulse first application time. The pulse first application time is the time when the pulse first appears when the atomic cloud is Raman cooled. Based on the initial centroid velocity of the atomic cloud, and the pulse application time and effective wave vector direction corresponding to the initial thermal velocity of each target, the pulse timing information of the initial thermal velocity of each target is determined. The pulse timing information includes: the angular frequency difference, pulse time, radio frequency, light intensity and light power of the two Raman lasers applied to each target initial thermal velocity. After determining the pulse timing information of the initial thermal velocity of the last target, a pulse timing information table is obtained based on the pulse timing information corresponding to the initial thermal velocity of each target.

[0007] Secondly, this application provides a radio frequency output device, characterized in that it includes: An FPGA control module, wherein the FPGA control module is configured with the pulse timing information determined by the method described in the first aspect; A temperature-controlled crystal oscillator is used to output a reference clock signal; A clock buffer, connected to the output of the oven-controlled crystal oscillator, is used to output multiple clock signals with consistent phase. A phase-locked loop module, connected to the output of the clock buffer, is used to generate a microwave baseband signal; A direct digital frequency synthesis module is connected to the output of the clock buffer and is used to generate radio frequency signals under the control of the FPGA control module. A mixer, connected to the output of the phase-locked loop module and the output of the direct digital frequency synthesis module, is used to mix the microwave baseband signal with the radio frequency signal. A bandpass filter, connected to the output of the mixer, is used to select a target frequency band signal from the mixed microwave baseband signal and the radio frequency signal. A low-noise amplifier and an RF power amplifier are connected in sequence. The low-noise amplifier is connected to the output of the bandpass filter to enhance the signal power of the target frequency band signal. An RF switch is disposed between the low-noise amplifier and the RF power amplifier. The control terminal of the RF switch is connected to the FPGA control module and is used to control the signal output time window so that the signal output time window corresponds to the pulse time.

[0008] Thirdly, this application provides a cold atom gravimeter, including: a radio frequency output device as described in the second aspect.

[0009] Fourthly, this application provides a timing control system for a cold atom gravimeter that manipulates the evolution of velocity distribution, comprising: The acquisition module is used to acquire the initial centroid velocity, initial thermal velocity, and target thermal velocity of the atomic cloud. A segmentation module is used to determine the initial thermal velocities of multiple targets based on the initial thermal velocity of the atomic cloud; The processing module is configured to: determine the effective wave vector direction for Raman cooling of each target initial thermal velocity based on each target initial thermal velocity; acquire the pulse application time corresponding to each target initial thermal velocity, wherein the pulse application time corresponding to each target initial thermal velocity is determined by the pulse application time, pulse duration, and pulse interval of the previous pulse, or is the pulse first application time, wherein the pulse first application time is the time when the pulse first appears during Raman cooling of the atomic cloud; determine the pulse timing information of each target initial thermal velocity based on the initial centroid velocity of the atomic cloud, and the pulse application time and effective wave vector direction corresponding to each target initial thermal velocity, wherein the pulse timing information includes: the angular frequency difference, pulse duration, radio frequency, light intensity, and light power of the two Raman laser beams applied to each target initial thermal velocity; and acquire a pulse timing information table based on the pulse timing information corresponding to each target initial thermal velocity after determining the pulse timing information of the last target initial thermal velocity.

[0010] Fifthly, this application provides an electronic device, including: a processor and a memory; The memory stores instructions that the computer executes; The processor executes computer execution instructions stored in memory, causing the processor to perform the method as described in any of the first aspects.

[0011] In a sixth aspect, embodiments of this application provide a readable storage medium including a program or instructions that, when run on a computer, execute the method described in any of the first aspects above.

[0012] In a seventh aspect, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the method described in any of the first aspects.

[0013] This application provides a timing control method and apparatus for a cold atom gravimeter that manipulates the evolution of velocity distribution. After acquiring the initial centroid velocity, initial thermal velocity, and target thermal velocity of an atomic cloud, multiple target initial thermal velocities are determined based on the initial thermal velocity of the atomic cloud. For each target initial thermal velocity, the effective wave vector direction for Raman cooling is determined. The pulse application time corresponding to each target initial thermal velocity is obtained. The pulse application time corresponding to each target initial thermal velocity is determined by the pulse application time, pulse duration, and pulse interval of the previous pulse, or by the pulse's first application time. Based on the initial centroid velocity of the atomic cloud, the pulse application time corresponding to each target initial thermal velocity, and the effective wave vector direction, the pulse timing information for each target initial thermal velocity is determined. After determining the pulse timing information for the last target initial thermal velocity, a pulse timing information table is obtained based on the pulse timing information corresponding to each target initial thermal velocity. In this embodiment, radio frequency (RF) driving light pulses matching the instantaneous centroid velocity and thermal velocity distribution are introduced during the atomic fall process. This allows atoms with different instantaneous centroid velocities and thermal velocity distributions to be sequentially acted upon by the matching RF driving light pulses, thereby rapidly reducing the width of the thermal velocity distribution of the atoms. This effectively increases the proportion of atoms participating in effective interference or momentum transfer processes, thereby enhancing the contrast of atomic signals and the visibility of interference fringes. This has a direct effect on the sensitivity of gravity measurements and the reduction of statistical noise. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 A flowchart of a cold atom gravimeter timing control method for manipulating velocity distribution evolution provided in an embodiment of this application; Figure 2 A schematic diagram of the thermal velocity distribution of atomic clouds conforming to a Gaussian distribution is provided for an embodiment of this application; Figure 3 A pulse timing diagram provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a radio frequency output device provided in an embodiment of this application; Figure 5A schematic diagram of the structure of a cold atom gravimeter timing control system for manipulating velocity distribution evolution is provided in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0017] Figure 1 This is a flowchart of a timing control method for a cold atom gravimeter that manipulates the evolution of velocity distribution, according to an embodiment of this application. The method is executed by a control system with logic processing capabilities. This control system can be independent of the cold atom gravimeter or it can be part of the cold atom gravimeter's control system. Figure 1 As shown, the method includes: S101. Obtain the initial centroid velocity, initial thermal velocity, and target thermal velocity of the atomic cloud.

[0018] In this step, the velocity of the center of mass of the atomic cloud is the velocity of the atomic cloud during free fall, which is related to the duration of fall and the gravitational acceleration. Here, the gravitational acceleration is the conventional gravitational acceleration used in existing technology, with a value of 9.8 m / s². 2 The initial centroid velocity of the atomic cloud is the centroid velocity of the atomic cloud in free fall after initial cooling by laser cooling and magneto-optical trap technology in the cold atom gravimeter. The initial centroid velocity of the atomic cloud in free fall is extremely small. In this embodiment, the initial centroid velocity of the atomic cloud is recorded as 0 m / s.

[0019] Atomic clouds not only undergo free fall under the influence of gravity, but also exhibit random thermal motion due to temperature. The distribution of thermal velocities corresponding to this random thermal motion conforms to the following... Figure 2 The Gaussian distribution shown is in Figure 2 In the Gaussian distribution diagram shown, the more atoms in the center, the more accurate the measurement of absolute gravitational acceleration. Therefore, it is necessary to narrow the width of the thermal velocity distribution. The initial thermal velocity of the atomic cloud refers to the thermal velocity distribution of the atomic cloud some time after the start of free fall motion and before the moment of the first pulse. Figure 2 Curve 1 in the figure. It should be noted that the initial thermal velocity of the atomic cloud is independent of the free fall time and is adjusted by Raman laser.

[0020] The target thermal velocity of an atomic cloud is the thermal velocity distribution corresponding to the atomic cloud after Raman cooling. Ideally, the target thermal velocity of the atomic cloud is 0, meaning that the more atoms in the cloud whose thermal velocities are zero relative to the instantaneous center of mass velocity, the more accurate the measurement of absolute gravitational acceleration. However, in reality, the velocity distribution curve corresponding to the thermal velocity of an atomic cloud is a Gaussian curve, with the thermal velocity corresponding to the middle position of the Gaussian curve denoted as 0 m / s. Therefore, in a cold atom gravimeter, the more atoms close to the middle position of the Gaussian curve, the narrower the width of the velocity distribution corresponding to the thermal velocity of the atomic cloud, and the more accurate the measurement of absolute gravitational acceleration. Thus, the target thermal velocity of an atomic cloud actually corresponds to a velocity distribution range, typically [-0.54 m / s, 0.54 m / s]. When the thermal velocities of most atoms are concentrated in [-0.54 m / s, 0.54 m / s], it indicates that the thermal velocity distribution of the atomic cloud has reached the target thermal velocity distribution, and absolute gravitational acceleration can be measured.

[0021] The thermal velocity of an atomic cloud is related to temperature. Therefore, the thermal velocity of an atomic cloud is generally expressed in the microKelvin range. For example, the initial thermal velocity of an atomic cloud corresponds to the initial temperature, which is generally 10 μK. The corresponding initial thermal velocity of the atomic cloud is 1.7 m / s, meaning that the initial thermal velocity of most atomic clouds is concentrated in the range of [-1.7 m / s, 1.7 m / s]. When the target temperature of the atomic cloud is less than or equal to 1 μK, it indicates that the thermal velocity of the atomic cloud has reached the target thermal velocity, meaning that the thermal velocity of most atoms is concentrated in the range of [-0.54 m / s, 0.54 m / s].

[0022] The initial thermal velocity of the atomic cloud can be obtained by probing the two-dimensional density distribution of the atomic cloud through light absorption imaging, or by other methods. For details, please refer to existing technologies, which will not be elaborated here.

[0023] S102. Determine the initial thermal velocities of multiple targets based on the initial thermal velocity of the atomic cloud.

[0024] In this step, such as Figure 2 As shown, the instantaneous centroid velocity of the atomic cloud is corresponding to the midpoint of the Gaussian curve. v ( t The thermal velocity is 0 m / s, indicating the instantaneous centroid velocity relative to the atomic cloud at the midpoint of the Gaussian curve. The thermal velocity of the atomic cloud is 0 m / s. The left half of the Gaussian curve indicates that atoms within this velocity distribution are in free fall, moving upwards; the right half indicates that atoms within this velocity distribution are in free fall, moving downwards. Figure 2 In the Gaussian curve shown, the greater the distance from the midpoint of the Gaussian curve, the greater the thermal velocity of the atomic cloud.

[0025] exist Figure 2In the Gaussian curve shown, multiple initial thermal velocities of targets can be symmetrically determined with the midpoint of the Gaussian curve as the center. Here, the initial thermal velocity of a target is a definite value. When Raman cooling is performed on an atomic cloud whose thermal velocity is equal to the initial thermal velocity of the target, it is actually performing Raman cooling on an atomic cloud whose thermal velocity is close to or equal to the initial thermal velocity of the target.

[0026] Optionally, one specific implementation of S102 is as follows: S1021. Divide the distance between the initial thermal velocity of the atomic cloud and the target thermal velocity of the atomic cloud to obtain multiple velocity distributions.

[0027] S1022. For each velocity distribution, determine the corresponding target initial thermal velocity.

[0028] Specifically, assuming that the initial thermal velocities of most atomic clouds are distributed between [-1.5 m / s, 1.5 m / s], the negative values ​​of the initial thermal velocities of atomic clouds correspond to... Figure 2 The left half of the Gaussian curve corresponds to the positive value. Figure 2 The right half of the Gaussian curve is divided into multiple velocity distributions with 0 as the intermediate value, for example, [-1.5m / s, -1.2m / s], [-1.2m / s, -0.9m / s], [-0.9m / s, -0.6m / s], [-0.6m / s, -0.3m / s], [-0.3m / s, 0.3m / s], [0m / s, 0.3m / s], [0.3m / s, 0.6m / s], [0.6m / s, 0.9m / s], [0.9m / s, 1.5m / s].

[0029] For each velocity distribution, a corresponding target initial thermal velocity is determined. The target initial thermal velocity can be the average of the thermal velocities at both ends of each velocity distribution. For example, for [-1.5 m / s, -1.2 m / s], the target initial thermal velocity is -1.35 m / s.

[0030] S103. Determine the effective wave vector direction for Raman cooling of each target based on its initial thermal velocity.

[0031] In this step, atoms located in the left half of the Gaussian curve move upwards relative to their free fall, while atoms located in the right half of the Gaussian curve move downwards relative to their free fall. For atoms moving upwards relative to their free fall, a downward impulse is needed to bring the thermal velocity of this part of the atomic cloud closer to 0; therefore, the effective wave vector direction is downwards. For atoms moving downwards relative to their free fall, an upward impulse is needed to bring the thermal velocity of this part of the atomic cloud closer to 0; therefore, the effective wave vector direction is upwards.

[0032] S104. Obtain the pulse application time corresponding to the initial thermal velocity of each target.

[0033] The pulse application time corresponding to the initial thermal velocity of each target is determined by the pulse application time, pulse time, and pulse interval of the previous pulse, or by the pulse first application time. The pulse first application time is the moment when the pulse first appears when Raman cooling the atomic cloud.

[0034] In this step, for each target's initial thermal velocity, it is necessary to determine the pulse application time. Let's take any target's initial thermal velocity as an example: When the initial thermal velocity of the target is the same as that of the first target to undergo Raman cooling, the corresponding pulse application time is the pulse first application time. The pulse first application time can be any time, provided that the thermal velocity of the atomic cloud after Raman cooling meets the target thermal velocity.

[0035] When the initial thermal velocity of the target is not the initial thermal velocity of the first target to undergo Raman cooling, the corresponding pulse application time is determined by the pulse application time, pulse duration, and pulse interval of the previous pulse. The pulse duration of the previous pulse is the duration of the pulse composed of two Raman laser beams when Raman cooling the atomic cloud with the previous initial thermal velocity. The pulse interval is the duration between the end of the previous pulse and the application time of this pulse. The pulse interval is used to allow the atomic cloud sufficient time to return to its initial quantum state through optical pumping between pulses, thus preparing it for the next effective momentum transfer operation (Raman cooling operation). The pulse interval is determined experimentally; in this embodiment, the pulse interval is 50 μs. However, the pulse interval can be greater than 50 μs, provided that the thermal velocity of the Raman-cooled atomic cloud meets the target thermal velocity.

[0036] S105. Based on the initial centroid velocity of the atomic cloud and the pulse application time and effective wave vector direction corresponding to the initial thermal velocity of each target, determine the pulse timing information of the initial thermal velocity of each target.

[0037] The pulse timing information includes: the angular frequency difference, pulse time, radio frequency, light intensity, and light power of the two Raman lasers applied to the initial thermal velocity of each target.

[0038] In this step, the pulse application time corresponding to the initial centroid velocity of the atomic cloud and the target initial thermal velocity is used to obtain the instantaneous centroid velocity of the atomic cloud at the pulse application time corresponding to the target initial thermal velocity.

[0039] Based on the instantaneous centroid velocity of the atomic cloud, the initial thermal velocity of the target, and the effective wave vector direction, the angular frequency difference, pulse time, radio frequency, light intensity, and light power of the two Raman laser beams are determined, thereby obtaining the pulse timing information corresponding to the initial thermal velocity of the target.

[0040] S106. After determining the pulse timing information of the initial thermal velocity of the last target, obtain the pulse timing information table according to the pulse timing information corresponding to the initial thermal velocity of each target.

[0041] In this step, after Raman cooling of the initial thermal velocity of each target, the velocity distribution width of the atomic cloud shrinks, and the thermal velocities of more atomic clouds are closer to the thermal velocities corresponding to the middle of the Gaussian curve. Thus, based on the pulse timing information corresponding to the initial thermal velocity of each target, a pulse timing information table is obtained.

[0042] It should be noted that in practice, the atoms need to be cooled multiple times. Therefore, one specific implementation of S106 is as follows: S1061. After determining the pulse timing information of the initial thermal velocity of the last target, obtain the intermediate thermal velocity of the atomic cloud.

[0043] Specifically, the intermediate thermal velocity of an atomic cloud refers to the thermal velocity distribution of the atomic cloud after a stage of Raman cooling, for example, Figure 2 Curve 2 in the diagram.

[0044] The intermediate thermal velocity of an atomic cloud can be obtained by probing the two-dimensional density distribution of the atomic cloud through light absorption imaging, or by other methods. For details, please refer to existing technologies, which will not be elaborated here.

[0045] S1062. Based on the intermediate thermal velocity and target thermal velocity of the atomic cloud, determine whether to perform Raman cooling on the atomic cloud again. If yes, proceed to S1063; otherwise, proceed to S1064.

[0046] Specifically, if the Gaussian curve corresponding to the thermal velocity distribution does not satisfy the Gaussian curve corresponding to the target thermal velocity distribution after Raman cooling, that is, if the thermal velocity distribution of the atomic cloud is still relatively wide, then another round of Raman cooling is required; otherwise, Raman cooling is no longer needed.

[0047] S1063. Take the intermediate thermal velocity of the atomic cloud as the initial thermal velocity of the atomic cloud, and determine several new target initial thermal velocities.

[0048] Specifically, the intermediate thermal velocity of the atomic cloud is taken as the initial thermal velocity of the atomic cloud, and S102-S106 are executed.

[0049] It should be noted that executing S102-S106, which is the next stage of Raman cooling, is a continuation of the previous stage of Raman cooling. In this Raman cooling stage, the pulse application time corresponding to the initial thermal velocity of the target is determined by the pulse application time, pulse duration, and pulse interval of the last pulse in the previous stage of Raman cooling.

[0050] S1064. Obtain the pulse timing information table based on the pulse timing information corresponding to the initial thermal velocity of each target.

[0051] Specifically, when the intermediate thermal velocity of the atomic cloud reaches the target thermal velocity, if the Raman cooling stage includes one stage, a pulse timing information table is obtained based on the pulse timing information corresponding to the initial thermal velocity of each target in that stage; if the Raman cooling stage includes at least two stages, a pulse timing information table is obtained based on the pulse timing information corresponding to the initial thermal velocity of each target in all stages. The pulse timing information in the table is sorted from front to back according to the pulse application time corresponding to each initial thermal velocity of the target.

[0052] After obtaining the pulse timing information table, the pulse timing information table is set into the radio frequency output device. The radio frequency output device outputs two Raman laser beams according to each pulse timing information in the pulse timing information table to perform Raman cooling on the atomic cloud and reduce the velocity distribution width of the thermal velocity.

[0053] In this embodiment, after obtaining the initial centroid velocity, initial thermal velocity, and target thermal velocity of the atomic cloud, multiple target initial thermal velocities are determined based on the initial thermal velocity of the atomic cloud. Based on each target initial thermal velocity, the effective wave vector direction for Raman cooling of each target initial thermal velocity is determined. The pulse application time corresponding to each target initial thermal velocity is obtained. The pulse application time corresponding to each target initial thermal velocity is determined by the pulse application time, pulse duration, and pulse interval of the previous pulse, or by the pulse's first application time. Based on the initial centroid velocity of the atomic cloud, and the pulse application time and effective wave vector direction corresponding to each target initial thermal velocity, the pulse timing information of each target initial thermal velocity is determined. After determining the pulse timing information of the last target initial thermal velocity, a pulse timing information table is obtained based on the pulse timing information corresponding to each target initial thermal velocity. In this embodiment, radio frequency (RF) driving light pulses matching the instantaneous centroid velocity and thermal velocity distribution are introduced during the atomic fall process. This allows atoms with different instantaneous centroid velocities and thermal velocity distributions to be sequentially acted upon by the matching RF driving light pulses, thereby rapidly reducing the width of the thermal velocity distribution of the atoms. This effectively increases the proportion of atoms participating in effective interference or momentum transfer processes, thereby enhancing the contrast of atomic signals and the visibility of interference fringes. This has a direct effect on the sensitivity of gravity measurements and the reduction of statistical noise.

[0054] Optional, for Figure 2 As shown in the Gaussian curve, the farther away from the center of the Gaussian curve, the greater the thermal velocity of the atom. The greater the thermal velocity, the faster the diffusion. Therefore, atoms with high thermal velocities need to be preferentially cooled. Therefore, before S104, the method further includes: S201. Determine the pulse application sequence among multiple target initial thermal velocities based on the target thermal velocity of the atomic cloud and the initial thermal velocity of each target.

[0055] In this step, the target thermal velocity of the atomic cloud corresponds to a position near the middle of the Gaussian curve. On the Gaussian curve, the farther the target initial thermal velocity is from the center, the greater the thermal velocity of the atomic cloud. Therefore, based on the target thermal velocity of the atomic cloud and the spacing of each target initial thermal velocity on the Gaussian curve, the pulse application order among multiple target initial thermal velocities is determined.

[0056] Optionally, S201 can be implemented as follows: S2011, Obtain the target thermal velocity of the atomic cloud and the spacing between the initial thermal velocities of each target.

[0057] Specifically, the target thermal velocity of the atomic cloud is set to 0. The thermal velocities of atomic clouds located in the left half of the Gaussian curve are negative, and those in the right half are positive. However, the negative and positive signs indicate the direction of the atomic cloud's thermal velocity relative to the instantaneous center-of-mass velocity, while the absolute value represents the magnitude of the atomic cloud's thermal velocity relative to the target thermal velocity. Therefore, the distance between the target thermal velocity of the atomic cloud and the initial thermal velocity of each target on the Gaussian curve is obtained.

[0058] S2012. Determine the pulse application sequence among the initial thermal velocities of multiple targets in descending order of spacing.

[0059] Specifically, on the Gaussian curve, the greater the distance from the center, the greater the thermal velocity of the atomic cloud relative to the target thermal velocity. Therefore, the larger the spacing, the greater the priority of Raman cooling. Thus, the pulse application order among multiple target initial thermal velocities is determined according to the order of spacing from large to small.

[0060] In this embodiment, on the Gaussian curve, the greater the distance from the center, the greater the priority of Raman cooling. That is, atomic clouds with high thermal velocity are cooled first. Furthermore, after the thermal velocity of atomic clouds moving at high thermal velocity decreases, the cooled thermal velocity falls within the Raman cooling range of other target initial thermal velocities that are lower than the target's initial thermal velocity. This means that when cooling atomic clouds with other target initial thermal velocities that are lower than the target's initial thermal velocity, the decelerated atomic clouds will also be cooled again, thereby improving the cooling efficiency and effect.

[0061] The following is a specific example illustrating a timing control method for a cold atom gravimeter that manipulates the evolution of velocity distribution according to this application: by Taking atoms as an example, before Raman cooling, the basic parameters of the experimental atom (i.e., the atom) are first determined and relevant data are set, and the wave vector direction is clarified. The basic parameters of the atom include: atomic mass, D2 line wavelength, natural linewidth, saturation intensity, ground-state hyperfine splitting frequency, single-photon recoil velocity, and single-photon recoil frequency. The relevant data includes: initial atomic state, environmental conditions, laser system, and timing parameters. The initial atomic state includes: initial temperature and number of atoms. The initial temperature is related to the initial thermal velocity distribution of the atomic cloud. The laser system is the radio frequency output device of this application, used to output two Raman laser beams. The timing parameters are obtained using the pulse timing information table determined in this application.

[0062] During Raman cooling, two Raman laser beams are emitted horizontally in the same direction from the same radio frequency output device. After reflection, they are directed vertically and act on freely falling atoms. The beams undergo total internal reflection at their lowest point and then act on the atoms in the opposite direction. Two laser beams with angular frequencies of ω1 and ω2 (ω1>ω2) are emitted from the radio frequency output device, and the direction of +z is defined as ω1>ω2 and perpendicularly downward.

[0063] During cooling, the rate of change in thermal velocity is generally an integer multiple of the photon recoil velocity, where the photon recoil velocity is... v rec ≈0.0059 m / s, therefore, the initial thermal velocity of the target is generally set to an integer multiple of the photon recoil velocity, i.e., v = nv rec .

[0064] During Raman cooling, the initial centroid velocity, initial thermal velocity, and target thermal velocity of the atomic cloud were set to 0 m / s, 10 m / s, and 10 m / s, respectively. v rec The pulse speed is 0 m / s; the pulse first action time T is 10 ms, that is, Raman cooling begins when the atom is in free fall for 10 ms; the pulse interval is set to 50 μs, that is, the next pulse arrives 50 μs after the previous pulse is completed.

[0065] In this embodiment, the initial thermal velocities of the multiple targets are 9 v rec 5 v rec 3 v rec 2 v rec and 1 v rec The pulse application sequence is as follows: 9 v rec 5 v rec 3 v rec 2v rec and 1 v rec .

[0066] The formula for calculating the angular frequency difference between two Raman laser beams is: Formula 1 Formula 2 in, w 12 The angular frequencies corresponding to the two Raman laser beams w 1. w 2 angular frequency difference; v ( t () represents the instantaneous velocity of the center of mass. v ( t )= v 0+ gt , v 0 represents the initial centroid velocity of the atomic cloud; k eff The effective wave vector is taken as 1.61 × 10^7 m. -1 ;δ 10 For the first zero-point detuning, τ is the pulse duration; w 0 is the eigenfrequency (angular frequency) of the Raman transition between two ground hyperfine levels of an atom.

[0067] The formula for calculating the pulse time of two Raman laser beams is: Formula 3 Formula 4 in, For effective wave vector k eff The pulse time corresponding to the downward (positive) direction. For effective wave vector k eff The pulse duration corresponding to the upward (negative) direction.

[0068] The process of calculating the intensity of two Raman laser beams is as follows: Formula 5 in, The effective rabi frequency can also be expressed as I0 is the saturation intensity, Γ is the natural linewidth of the excited state, Δ is the single-photon detuning, where D2 line detuning Δ = 2π × 1.5 GHz, and C is the polarization factor, which depends on the initial state in the F = 3 manifold, with an average value of =0.28, with a deviation of ±20%. Among them, I0, Γ, Δ, and C are known parameters.

[0069] Therefore, the formula for calculating the intensity of two Raman laser beams is: Formula 6 The formula for calculating the optical power of two Raman laser beams is: Formula 7: P=I×A Where P is the optical power, I is the optical intensity, and A is the effective area of ​​the beam.

[0070] The formula for calculating the radio frequency of two Raman laser beams is: Formula 8 Formula 9 in, f 0 represents the radio frequency of the radio frequency signal output by the radio frequency output device, which is taken as 6.834015 GHz in this application.

[0071] It should be noted that when the effective wave vector k eff When the direction is downward (positive), use formulas 1, 3, 6, 7, and 8 to obtain pulse timing information; when the effective wave vector... k eff When the direction is upward (negative), use formulas 2, 4, 6, 7 and 9 to obtain pulse timing information.

[0072] Therefore, for the thermal velocity of the right half of the Gaussian curve, when T=10ms, the initial thermal velocity of the target is 9. v rec The atoms are cooled. It should be noted that although the initial thermal velocity of the target is a fixed value, during Raman cooling, the thermal velocity is adjusted relative to the initial thermal velocity of the target (e.g., 9). v rec Nearby atoms are cooled. The instantaneous center-of-mass velocity of the atomic cloud is: v (T=10ms) = g⋅t = 0.098m / s, effective wave vector. k eff The direction is upward (negative), i.e., the -z direction.

[0073] Therefore, when T=10ms, the initial thermal velocity of the target in the right half is 9. v rec The corresponding parameters are input into the corresponding formula to obtain the corresponding pulse timing information: T=10ms, pulse time is 2.584μs, and radio frequency is... f =6.834015GHz - 51.85kHz = 6.833963GHz, light intensity is approximately 260.8W / m² 2 The optical power is approximately 5.12mW (spot radius approximately 2.5mm).

[0074] For the thermal velocity in the left half of the Gaussian curve, when T=10ms, the initial thermal velocity of the target is 9. v rec The atoms are cooled, and at this time, the instantaneous center-of-mass velocity of the atomic cloud is: v (T=10ms) = g⋅t = 0.098m / s. Effective wave vector k eff The direction is downwards, i.e., the +z direction.

[0075] Therefore, when T=10ms, the initial thermal velocity of the target in the left half is 9. v rec The corresponding parameters are input into the corresponding formulas to obtain the corresponding pulse timing information: T=10ms, pulse time is 8.686μs, and radio frequency is... f =6.834015GHz + 214.59 kHz = 6.834230 GHz, with a light intensity of approximately 877 W / m². 2 The optical power is approximately 17.22 mW (spot radius approximately 2.5 mm).

[0076] Then, based on the above process, the initial thermal velocity of the target is 5. v rec 3 v rec 2 v rec and 1 v rec The pulse timing information obtained by performing MAN cooling is as follows: Figure 3 As shown, the specific calculation process will not be repeated here.

[0077] After Raman cooling according to the above process, the velocity distribution curve of the intermediate thermal velocity of the atomic cloud is as follows: Figure 2 As shown in curve 2, comparing curve 1 and curve 2, after one round of Raman cooling, the velocity distribution width of the thermal velocity of the atomic cloud shrinks.

[0078] After comparing the intermediate thermal velocity of the atomic cloud obtained through one round of Raman cooling with the target thermal velocity, the atomic cloud's thermal velocity needs to be cooled again, and the above process is repeated until the intermediate thermal velocity of the atomic cloud reaches the target thermal velocity. Figure 2 Curve 3 in the figure represents the Gaussian curve of the thermal velocity of the atomic cloud after Raman cooling.

[0079] It should be noted that in this example, the specific values ​​of thermal velocity, such as the initial thermal velocity of the atomic cloud and the initial thermal velocity of the target, are only used to describe the calculation process. In actual applications, the data involved should be based on the actual data, which includes: the initial centroid velocity of the atomic cloud, gravitational acceleration, the initial thermal velocity of the atomic cloud, and the initial thermal velocity of the target.

[0080] Figure 4 This is a schematic diagram of the structure of a radio frequency output device provided in an embodiment of this application. Figure 4 As shown, the radio frequency output device includes: FPGA control module 401, which is equipped with a pulse timing information table determined by any of the above method embodiments; The oven-controlled crystal oscillator 402 is used to output a reference clock signal; Clock buffer 403 is connected to the output of oven-controlled crystal oscillator 402 and is used to output multiple clock signals with consistent phase. The phase-locked loop module 404 is connected to the output of the clock buffer 403 and is used to generate microwave baseband signals; The direct digital frequency synthesis module 405 is connected to the output of the clock buffer 403 and is used to generate radio frequency signals under the control of the FPGA control module 401. Mixer 406 is connected to the output of phase-locked loop module 404 and the output of direct digital frequency synthesis module 405, and is used to mix microwave baseband signal and radio frequency signal. A bandpass filter 407 is connected to the output of a mixer 406 and is used to select a target frequency band signal from the mixed microwave baseband signal and radio frequency signal. The low-noise amplifier 408 and the radio frequency power amplifier 409 are connected in sequence. The output terminal of the low-noise amplifier 408 is connected to the bandpass filter 407 to enhance the signal power of the target frequency band signal. An RF switch is located between the low-noise amplifier 408 and the RF power amplifier 409. The control terminal of the RF switch is connected to the FPGA control module 401 and is used to control the signal output time window so that the signal output time window corresponds to the pulse time.

[0081] In this embodiment, the process of the radio frequency output device outputting pulses is as follows: The oven-controlled crystal oscillator is used to provide a frequency reference with high stability and low phase noise to ensure the long-term stability and consistency of subsequent radio frequency and microwave signals. The oven-controlled crystal oscillator 402 outputs a reference clock signal with a frequency of 100 MHz and inputs the reference clock signal with a frequency of 100 MHz to the clock buffer 403.

[0082] The clock buffer 403 outputs at least two 100MHz clock signals with the same phase based on a reference clock signal with a frequency of 100 MHz. One of them is used to drive the phase-locked loop module 404 (i.e., the phase-locked loop circuit PLL), and the other is used to drive the direct digital frequency synthesis module 405 (DDS405) to ensure the phase synchronization between the signal sources.

[0083] The phase-locked loop (PLL) circuit generates a stable microwave baseband signal of approximately 6.7 GHz through frequency multiplication and phase-locked control, and inputs it to the mixer 406. The microwave baseband signal serves as the base carrier for subsequent radio frequency frequency shifting and modulation.

[0084] Under the control of the FPGA control module 401, the DDS405 generates radio frequency signals with a frequency range of 0 to 200 MHz and inputs them to the mixer 406. The 0 to 200 MHz radio frequency signals enable precise programmable control of the radio frequency signal frequency, phase and output timing.

[0085] Mixer 406 performs frequency mixing processing on the 6.7 GHz microwave baseband signal and the RF signal output from DDS 405 to obtain a mixed RF signal with a frequency range of 6.7 GHz to 6.9 GHz; the subsequent bandpass filter 407 selects the desired frequency band signal and suppresses unwanted sum frequency, difference frequency, and spurious signals. The filtered RF signal is sequentially input into a low-noise amplifier 408 and an RF power amplifier 409 to boost the signal amplitude, ensuring it meets the driving power requirements for subsequent optical modulation or cold atom processing. This yields an RF signal in the frequency range of 6.7 GHz to 6.9 GHz, as described in Equations 8 and 9. f 0.

[0086] In this process, an RF switch is set in the RF signal amplification path, and the control terminal of the RF switch is connected to the FPGA control module 401. The FPGA control module 401 precisely controls the conduction and cutoff of the RF switch according to the pulse timing information table, thereby limiting the effective action time window of the RF signal.

[0087] In this way, after the atom is released, it falls freely under the action of gravity. The FPGA control module 401 performs timing control according to the free fall time of the atom. When the atom falls to the pulse application time (for example, about 10ms), it controls the RF switch to be turned on so that the RF signal is output within the corresponding pulse time.

[0088] It should be noted that the radio frequency driven light field acting on cold atoms is achieved by outputting a radio frequency signal in the range of 6.7 GHz to 6.9 GHz to an optical modulation device, which drives an acousto-optic modulator to generate two Raman beams with corresponding frequencies and intensities within a time window. The two Raman beams interact with the atoms, enabling the atoms to obtain additional optical momentum transfer, realize the separation or manipulation of large momentum states, and thus achieve the compression of thermal velocity distribution.

[0089] It should be noted that, as Figure 4 As shown, after the phase-locked loop (PLL) circuit, a bandpass filter 407 and a low-noise amplifier 408 are sequentially set to process the microwave carrier signal. Furthermore, the processed microwave carrier signal can be adjusted and attenuated before being input to the mixer 406.

[0090] Optionally, the RF signal can be attenuated in an adjustable manner between the RF switch and the RF power amplifier 409.

[0091] Optionally, a low-pass filter 410 is provided after the RF power amplifier 409 to perform low-pass filtering on the RF signal output by the RF power amplifier 409, thereby obtaining a stable RF signal in the range of 6.7 GHz to 6.9 GHz.

[0092] In this embodiment, by embedding the pulse timing information table determined by any of the above method embodiments into the FPGA control module 401, and using the method of FPGA scheduling combined with direct digital frequency synthesis, high-precision, low-jitter output of frequency jump and pulse control is achieved. This makes the pulses generated by the two Raman lasers output by this application highly programmable, highly efficient, and suitable for multiple working modes.

[0093] This application also provides a cold atom gravimeter, which includes the radio frequency output device provided in the above embodiments to achieve Raman cooling of atoms, thereby enabling the measurement of absolute gravitational acceleration.

[0094] Figure 5 This is a schematic diagram of the structure of a timing control system for a cold atom gravimeter that manipulates the evolution of velocity distribution, provided as an embodiment of this application. Figure 5 As shown, a timing control system for a cold atom gravimeter that manipulates the evolution of velocity distribution includes: an acquisition module 501, a partitioning module 502, and a processing module 503.

[0095] Among them, the acquisition module 501 is used to acquire the initial centroid velocity, initial thermal velocity, and target thermal velocity of the atomic cloud; The partitioning module 502 is used to determine multiple target initial thermal velocities based on the initial thermal velocity of the atomic cloud; The processing module 503 is configured to: determine the effective wave vector direction for Raman cooling of each target initial thermal velocity based on each target initial thermal velocity; acquire the pulse application time corresponding to each target initial thermal velocity, wherein the pulse application time corresponding to each target initial thermal velocity is determined by the pulse application time, pulse duration, and pulse interval of the previous pulse, or is the pulse first application time, wherein the pulse first application time is the time when the pulse first appears during Raman cooling of the atomic cloud; determine the pulse timing information of each target initial thermal velocity based on the initial centroid velocity of the atomic cloud, and the pulse application time and effective wave vector direction corresponding to each target initial thermal velocity, wherein the pulse timing information includes: the angular frequency difference, pulse duration, radio frequency, light intensity, and light power of the two Raman laser beams applied to each target initial thermal velocity; and acquire a pulse timing information table based on the pulse timing information corresponding to each target initial thermal velocity after determining the pulse timing information of the last target initial thermal velocity.

[0096] Optionally, before the processing module 503 obtains the pulse application time corresponding to the initial thermal velocity of each target, it is further configured to: The pulse application sequence among the plurality of target initial thermal velocities is determined based on the target thermal velocity of the atomic cloud and the initial thermal velocity of each target. Accordingly, the processing module 503 obtains the pulse application time corresponding to each of the target initial thermal velocities, specifically for: determining the pulse application time corresponding to each of the target initial thermal velocities according to the pulse application order among the multiple target initial thermal velocities.

[0097] Optionally, the processing module 503 determines the pulse application order among the plurality of initial thermal velocities of the atomic cloud based on the target thermal velocity and each of the target initial thermal velocities, specifically for: Obtain the target thermal velocity of the atomic cloud and the spacing between the initial thermal velocities of each target; The pulse application order among the initial thermal velocities of the multiple targets is determined according to the order of the spacing from largest to smallest.

[0098] Optionally, the partitioning module 502 determines multiple target initial thermal velocities based on the initial thermal velocity of the atomic cloud, specifically for: The distance between the initial thermal velocity of the atomic cloud and the target thermal velocity of the atomic cloud is divided to obtain multiple velocity distributions; For each velocity distribution, determine the corresponding target initial thermal velocity.

[0099] Optionally, after determining the pulse timing information of the last target's initial thermal velocity, the processing module 503 obtains a pulse timing information table based on the pulse timing information corresponding to each target's initial thermal velocity, specifically for: After determining the pulse timing information of the initial thermal velocity of the last target, the intermediate thermal velocity of the atomic cloud is obtained; Based on the intermediate thermal velocity and target thermal velocity of the atomic cloud, determine whether to perform Raman cooling on the atomic cloud again; If so, the intermediate thermal velocity of the atomic cloud is taken as the initial thermal velocity of the atomic cloud, and multiple new target initial thermal velocities are determined. If not, obtain the pulse timing information table based on the pulse timing information corresponding to the initial thermal velocity of each target.

[0100] The timing control system for the cold atom gravimeter that manipulates the velocity distribution evolution provided in this application embodiment can be found in the above method embodiment in its specific implementation process. The implementation principle and technical effect are similar, and will not be repeated here.

[0101] Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device may be a server corresponding to a control system, such as... Figure 6 As shown, the electronic device includes a processor 601 and a memory 602.

[0102] The memory 602 stores computer-executed instructions.

[0103] The processor 601 executes the computer execution instructions stored in the memory 602, causing the processor 601 to perform the method described in any of the above embodiments.

[0104] The electronic device provided in this application embodiment can be referred to the above method embodiment for its specific implementation process. The implementation principle and technical effect are similar, and will not be repeated here.

[0105] In the above Figure 6 In the illustrated embodiments, it should be understood that the processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor.

[0106] The memory may include high-speed RAM, and may also include non-volatile storage (NVM), such as at least one disk storage.

[0107] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0108] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the method shown in the above-described method embodiments.

[0109] The aforementioned computer-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0110] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an application-specific integrated circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0111] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A timing control method for a cold atom gravimeter that manipulates the evolution of velocity distribution, characterized in that, include: Obtain the initial centroid velocity, initial thermal velocity, and target thermal velocity of the atomic cloud; Based on the initial thermal velocity of the atomic cloud, determine the initial thermal velocities of multiple targets; Based on the initial thermal velocity of each target, determine the effective wave vector direction for Raman cooling of each target's initial thermal velocity; The pulse application time corresponding to the initial thermal velocity of each target is obtained. The pulse application time corresponding to the initial thermal velocity of each target is determined by the pulse application time, pulse time, and pulse interval of the previous pulse, or it is the pulse first application time. The pulse first application time is the time when the pulse first appears when the atomic cloud is Raman cooled. Based on the initial centroid velocity of the atomic cloud, and the pulse application time and effective wave vector direction corresponding to the initial thermal velocity of each target, the pulse timing information of the initial thermal velocity of each target is determined. The pulse timing information includes: the angular frequency difference, pulse time, radio frequency, light intensity and light power of the two Raman lasers applied to each target initial thermal velocity. After determining the pulse timing information of the initial thermal velocity of the last target, a pulse timing information table is obtained based on the pulse timing information corresponding to the initial thermal velocity of each target.

2. The method according to claim 1, characterized in that, Before obtaining the pulse application time corresponding to the initial thermal velocity of each target, the method further includes: The pulse application sequence among the plurality of target initial thermal velocities is determined based on the target thermal velocity of the atomic cloud and the initial thermal velocity of each target. Accordingly, obtaining the pulse application time corresponding to the initial thermal velocity of each target includes: The pulse application time corresponding to each of the target initial thermal velocities is determined based on the pulse application sequence among the multiple target initial thermal velocities.

3. The method according to claim 2, characterized in that, The step of determining the pulse application order among the plurality of target initial thermal velocities based on the target thermal velocity of the atomic cloud and each target initial thermal velocity includes: Obtain the target thermal velocity of the atomic cloud and the spacing between the initial thermal velocities of each target; The pulse application order among the initial thermal velocities of the multiple targets is determined according to the order of the spacing from largest to smallest.

4. The method according to claim 1, characterized in that, The determination of multiple target initial thermal velocities based on the initial thermal velocity of the atomic cloud includes: The distance between the initial thermal velocity of the atomic cloud and the target thermal velocity of the atomic cloud is divided to obtain multiple velocity distributions; For each velocity distribution, determine the corresponding target initial thermal velocity.

5. The method according to claim 1, characterized in that, After determining the pulse timing information of the last target's initial thermal velocity, a pulse timing information table is obtained based on the pulse timing information corresponding to each target's initial thermal velocity, including: After determining the pulse timing information of the initial thermal velocity of the last target, the intermediate thermal velocity of the atomic cloud is obtained; Based on the intermediate thermal velocity and target thermal velocity of the atomic cloud, determine whether to perform Raman cooling on the atomic cloud again; If so, the intermediate thermal velocity of the atomic cloud is taken as the initial thermal velocity of the atomic cloud, and multiple new target initial thermal velocities are determined. If not, obtain the pulse timing information table based on the pulse timing information corresponding to the initial thermal velocity of each target.

6. A radio frequency output device, characterized in that, include: An FPGA control module, wherein the FPGA control module is provided with the pulse timing information determined by the method according to any one of claims 1-5; A temperature-controlled crystal oscillator is used to output a reference clock signal; A clock buffer, connected to the output of the oven-controlled crystal oscillator, is used to output multiple clock signals with consistent phase. A phase-locked loop module, connected to the output of the clock buffer, is used to generate a microwave baseband signal; A direct digital frequency synthesis module is connected to the output of the clock buffer and is used to generate radio frequency signals under the control of the FPGA control module. A mixer, connected to the output of the phase-locked loop module and the output of the direct digital frequency synthesis module, is used to mix the microwave baseband signal with the radio frequency signal. A bandpass filter, connected to the output of the mixer, is used to select a target frequency band signal from the mixed microwave baseband signal and the radio frequency signal. A low-noise amplifier and an RF power amplifier are connected in sequence. The low-noise amplifier is connected to the output of the bandpass filter to enhance the signal power of the target frequency band signal. An RF switch is disposed between the low-noise amplifier and the RF power amplifier. The control terminal of the RF switch is connected to the FPGA control module and is used to control the signal output time window so that the signal output time window corresponds to the pulse time.

7. A cold atom gravimeter, characterized in that, include: The radio frequency output device as described in claim 6.

8. An electronic device, characterized in that, include: Processor and memory; The memory stores the instructions that the computer executes; The processor executes computer execution instructions stored in memory, causing the processor to perform the method according to any one of claims 1-5.

9. A readable storage medium, characterized in that, include: A program or instruction that, when run on a computer, performs the method described in any one of claims 1-5.

10. A computer program product, characterized in that, Includes a computer program that, when executed by a processor, implements the method as described in any one of claims 1-5.

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