A laser spot rapid measurement method, system and terminal device

Abstract

The application provides a kind of laser spot fast measurement method, system and terminal equipment, belong to ion trap technical field, it is applied to including ion state preparation control component, ion trap component and the ion beam waist measurement device of laser incidence focusing component to be measured, method includes: obtaining each ion spatial position of multiple ion array, to control focusing component to make the spot of laser to be measured irradiation array obtains maximum response ion position;Under the duration of laser pulse time sequence, reference Rabi frequency is obtained according to ion position to generate fixed reference drive time;Control control component to exert the drive pulse of the laser to be measured on array for the duration of drive time, obtain bright-dark state result to obtain upper state occupation probability;Obtain spatial distribution model and ion laser local coupling strength, and combine upper state occupation probability and fixed time to invert spot center position, beam waist parameter and central coupling strength.The application realizes in situ fast measurement to laser spot at ion actual confinement position, and ensures measurement stability.

Description

Technical Field

[0001] This invention relates to the field of ion trap technology, and in particular to a method, system and terminal device for rapid measurement of laser spot. Background Technology

[0002] In experimental scenarios involving quantum computing, quantum simulation, and quantum precision measurement using ion trap systems, laser light fields are commonly used for ion cooling, quantum state preparation, quantum logic gate operations, sideband transition driving, and quantum state detection. The beam waist size, center position, and spatial intensity distribution of the laser beam in the laser light field directly affect the local coupling strength, Rabi frequency, addressing crosstalk, and quantum operation fidelity at the ion site. Therefore, there is an urgent need for a scheme that can accurately measure the center position, beam waist parameters, and central coupling strength of the laser beam at the ion trapping location and quickly calibrate the laser to ensure the stable operation of the ion trap system.

[0003] Existing technology prepares N target ions in a multidimensional ion chain within an ion trap to a unified initial quantum state. A control module outputs N radio frequency signals with different frequencies and amplitudes to drive an acousto-optic modulation unit to output N diffracted beams onto the N ions for a fixed duration. The control module acquires the probability that each ion will be excited to a set quantum state and obtains the Rabi frequency of each ion based on this probability. The control module updates its output using a feedback control law based on the Rabi frequency of the ion being measured, the target Rabi frequency of the ion to be calibrated, and the amplitude of the radio frequency signal irradiating the ion, until the Rabi frequencies of the N target ions reach a preset condition. This existing technology, through closed-loop feedback, can actively compensate online for complex crosstalk, optical aberrations, and slow system drift that are difficult to model, ultimately achieving high-fidelity reproduction of the light intensity distribution and ensuring the accuracy of laser measurements.

[0004] However, this existing technology relies on measuring the Rabi frequency of each target ion individually and iteratively controlling the feedback. Therefore, each laser measurement takes a long time, and the feedback convergence process involves multiple iterations, which is time-consuming and unstable. Thus, while this existing technology can ensure measurement accuracy, it cannot meet the stability requirements of laser spot measurement, and the laser spot measurement itself is very time-consuming. Summary of the Invention

[0005] The present invention aims to provide a method, system and device for rapid measurement of laser spot, in order to solve the above-mentioned technical problems, obtain the center position of the laser spot, beam waist parameters and central coupling intensity of the laser under test in the ion interaction region in situ and rapidly, and realize stable and rapid measurement of the center position of the laser spot, beam waist parameters and central coupling intensity of the laser under test.

[0006] To address the aforementioned technical problems, this invention provides a rapid laser spot measurement method, applicable to an ion beam waist measurement device comprising an ion state preparation and manipulation component, an ion trap component, and a laser incident focusing component, comprising the following steps: Obtain the spatial position of each ion in the multi-ion array fabricated by the ion trap assembly; Based on the spatial position, the laser under test incident focusing component is controlled to make the laser spot under test irradiate the multi-ion array for coarse response measurement, and the position of the maximum response ion is determined. Under a preset laser pulse duration sequence, a reference Rabi frequency is obtained based on the position of the maximum response ion, and a fixed reference driving time is generated based on the reference Rabi frequency; The control component is prepared according to the fixed reference driving time to apply a laser driving pulse of the test to a multi-ion array with a continuous fixed reference driving time, obtain the bright and dark state results of each ion in the multi-ion array, and obtain the population probability of the upper state based on the bright and dark state results. The spatial distribution model of the laser spot to be tested and the local coupling intensity of the ion laser are obtained. Based on the local coupling intensity of the ion laser, the population probability of the upper state, the fixed reference driving time, and the spatial distribution model, the center position of the laser spot to be tested, the beam waist parameters, and the center coupling intensity are obtained by inversion.

[0007] The above scheme first obtains the spatial position of each ion in the multi-ion array, and then controls the laser incident focusing component to illuminate the multi-ion array based on the spatial position, so that the laser spot covers at least part of the ions in the multi-ion array, without requiring the center of the laser spot to be precisely aligned with a specific ion in the multi-ion array. Thus, the position corresponding to the ion with the largest response is selected as the position of the largest response ion. This scheme, under a preset laser pulse duration sequence, adjusts the duration of the laser driving pulse at the position of the largest response ion to obtain a reference Rabi frequency reflecting the local effective Rabi frequency of the ion with the largest response in the coarse measurement of the multi-ion response under the current laser action. Based on this reference Rabi frequency, a fixed reference driving time is generated. This fixed reference driving time ensures that the population response at the position of the largest response ion is within a range sensitive to changes in local coupling strength. Subsequently… This scheme controls the ion state preparation manipulation component to apply a test laser driving pulse to each ion in a multi-ion array for a continuous fixed reference driving time. The resulting bright and dark state results of each ion and the obtained upper state population probability of each ion can improve the stability of the spot center position, beam waist parameters, and central coupling strength obtained by subsequent inversion. Moreover, this scheme only needs to perform population statistics for each ion under a fixed pulse driving time to obtain the upper state population probability, without acquiring a complete Rabi oscillation curve for each spatial position, thus reducing the overall calibration time. Based on the local coupling strength, upper state population probability, fixed reference driving time, and spatial distribution model, this scheme can invert the spot center position, beam waist parameters, and central coupling strength of the test laser for calibration, realizing stable and rapid measurement of the spot center position, beam waist parameters, and central coupling strength of the test laser.

[0008] Furthermore, obtaining the spatial position of each ion in the multi-ion array prepared by the ion trap assembly includes: obtaining the fluorescence image corresponding to each ion chain in the multi-ion array prepared by the ion trap assembly; extracting the center position of the fluorescence bright spot corresponding to each ion in the ion chain in the fluorescence image; and obtaining the spatial position of each ion based on the center position of the fluorescence bright spot through mapping processing.

[0009] Furthermore, the step of controlling the laser under test incident focusing component based on the spatial position to irradiate the multi-ion array with the laser spot under test for coarse response measurement and obtaining the position of the ion with the largest response includes: controlling the laser under test incident focusing component based on the spatial position to irradiate the multi-ion array with the laser spot under test for coarse response measurement, obtaining the initial response of each ion in the multi-ion array; obtaining the spatial position of the ion corresponding to the ion with the largest initial response, and using the spatial position of the ion as the position of the ion with the largest response.

[0010] The above-described scheme first controls the laser beam incident focusing component based on the spatial position of each ion, so that the laser beam illuminates the multi-ion array, guiding the beam to a region that covers at least a portion of the ions, without requiring the center of the beam to be precisely aligned with a specific ion, thus avoiding the time-consuming problem of precise alignment required in traditional schemes. Subsequently, this scheme selects the ion with the largest initial response based on the initial response distribution, and determines the position of the ion with the largest response by its corresponding spatial position. This provides a reliable basis for obtaining a fixed reference driving time, enabling in-situ and rapid acquisition of the beam center position, beam waist parameters, and central coupling strength of the laser beam under test, achieving stable and rapid measurement of these parameters.

[0011] Furthermore, after controlling the laser incident focusing component based on the spatial position to irradiate the multi-ion array with the laser spot for coarse response measurement and obtaining the initial response of each ion in the multi-ion array, the method further includes: confirming that the initial response of each ion is concentrated in a few adjacent ions or concentrated in a single particle, then obtaining the ion spacing, ion number, and ion trap axial binding strength of the multi-ion array; reducing the ion spacing and ion trap axial binding strength to obtain optimized ion spacing and optimized ion trap axial binding strength; increasing the ion number to obtain optimized ion number; configuring the ion trap component according to the optimized ion spacing, the optimized ion number, and the optimized ion trap axial binding strength, and the configured ion trap component is used in the next execution of the laser spot rapid measurement method.

[0012] When the initial responses of each ion in the above scheme are concentrated in a few adjacent ions or a single ion, it indicates that the number of effective spatial sampling points or the spatial coverage provided by the current multi-ion array is insufficient relative to the scale of the laser spot to be measured. If inversion is performed directly based on this sparse sampling, it is easy to cause instability in the fitting results of the spot center position and beam waist parameters. Therefore, this scheme obtains the ion spacing, ion number, and ion trap axial binding strength, and reduces the ion spacing and ion trap axial binding strength while increasing the ion number to obtain optimized parameters for reconfiguring the ion trap assembly. This allows the multi-ion array to provide denser spatial sampling points in the area of ​​the laser spot to be measured when the laser spot rapid measurement method is executed next time, thereby avoiding the situation of unstable fitting due to insufficient sampling density, improving the reliability of subsequent beam waist parameter inversion, and thus ensuring the stability of laser spot measurement.

[0013] Further, the step of obtaining a reference Rabi frequency based on the position of the maximum responding ion under a preset laser pulse duration sequence, and generating a fixed reference driving time based on the reference Rabi frequency, includes: preparing a manipulation component by controlling the ion state according to different durations in the preset laser pulse duration sequence, so as to apply laser driving pulses of different durations to be tested at the position of the maximum responding ion, and obtaining a Rabi oscillation curve; fitting the Rabi oscillation curve to obtain a reference Rabi frequency, and generating a fixed reference driving time based on the reference Rabi frequency.

[0014] The above scheme first controls the ion state preparation manipulation component to apply laser driving pulses of different durations at the position of the maximum response ion based on different durations in a preset laser pulse duration sequence, obtaining the Rabi oscillation curve as a function of duration. It can be seen that this scheme only needs to obtain the Rabi oscillation curve corresponding to the position of the maximum response ion, significantly reducing the time consumed compared to the traditional scheme that requires traversing all ions in a multi-ion array. Subsequently, this scheme fits the Rabi oscillation curve to obtain a reference Rabi frequency reflecting the local effective coupling strength at the position of the maximum response ion under the current laser irradiation, providing a reliable basis for subsequently determining the fixed reference driving time. Based on this reference Rabi frequency, a fixed reference driving time is generated, allowing subsequent applications of pulses with this fixed reference driving time to each ion in the multi-ion array to obtain the upper state population probability reflecting the difference in coupling strength at each ion's spatial position, without needing to collect a complete Rabi oscillation curve for each ion separately. Based on the fixed reference driving time, this scheme enables each ion to be measured within the sensitive response range, thus ensuring the stability of the inversion results and ensuring measurement stability while improving the laser spot measurement speed.

[0015] Further, the step of controlling the ion state preparation and manipulation component according to the fixed reference driving time to apply a test laser driving pulse with a continuous fixed reference driving time to the multi-ion array, obtaining the bright and dark state results of each ion in the multi-ion array, and obtaining the upper state population probability based on the bright and dark state results includes: obtaining the region of interest of each ion based on the spatial location; controlling the ion state preparation and manipulation component according to the fixed reference driving time to apply a test laser driving pulse with a continuous fixed reference driving time to the multi-ion array, obtaining the fluorescence intensity sequence corresponding to the region of interest of each ion in the multi-ion array; comparing the fluorescence intensity sequence of each ion at a preset bright state threshold to obtain the bright and dark state results; extracting the number of bright states of each ion from the bright and dark state results, and obtaining the upper state population probability based on the number of bright states.

[0016] The above scheme obtains the region of interest (ROI) for each ion based on its spatial location. A manipulation component is prepared to control the ion state according to a fixed reference driving time. A laser driving pulse of the target ion, lasting for the fixed reference driving time, is applied to the multi-ion array, and the fluorescence intensity sequence corresponding to the ROI of each ion is acquired. Since the fixed reference driving time is constant, there is no need to set different pulse durations for different ions, thus significantly reducing the overall calibration time. After acquiring the fluorescence intensity sequence, this scheme compares the fluorescence intensity sequence of each ion at a preset bright state threshold to obtain bright and dark state results. Then, the number of bright states for each ion is extracted from the bright and dark state results, and the upper-state population probability, which effectively suppresses random fluctuations in a single measurement, is obtained based on this number of bright states. This ensures that the upper-state population probability corresponding to each ion stably reflects the differences in local coupling strength at different spatial locations, thereby ensuring the stability of subsequent rapid measurement of the laser spot and improving the measurement speed.

[0017] Further, the step of obtaining the spatial distribution model of the laser under test and the local coupling intensity of the ion laser, and inverting the spot center position, beam waist parameters and center coupling intensity of the laser under test based on the local coupling intensity of the ion laser, the upper state population probability, the fixed reference driving time and the spatial distribution model, includes: obtaining the spatial distribution model of the laser under test and the local coupling intensity of the ion laser based on the spatial position and the upper state population probability; Under the fixed reference driving time, a population response model is generated based on the local coupling strength of the ion laser and the population probability of the upper state; the model population probability is obtained based on the population response model and the spatial distribution model; the measured population probability is obtained, and the measured population probability and the model population probability are fitted to construct a population probability target, and the center position of the laser spot, beam waist parameters and central coupling strength of the laser under test are obtained by inversion with the goal of minimizing the population probability target.

[0018] Further, after extracting the number of bright states for each ion from the bright and dark state results and obtaining the population probability of the upper state based on the number of bright states, the method further includes: extracting the maximum and minimum population probabilities of the upper state from the population probabilities of the upper state, and obtaining the difference between the population probabilities of the upper state based on the maximum and minimum population probabilities of the upper state; confirming that the difference between the population probabilities of the upper state is less than a preset difference threshold, then obtaining the ion spacing, ion quantity, and ion trap axial binding strength of the multi-ion array; reducing the ion spacing and the ion trap axial binding strength to obtain the population-optimized ion spacing and the population-optimized ion trap axial binding strength; increasing the ion quantity to obtain the population-optimized ion quantity; configuring the ion trap assembly based on the population-optimized ion spacing, the population-optimized ion quantity, and the population-optimized ion trap axial binding strength, and the configured ion trap assembly is used in the next execution of the laser spot rapid measurement method.

[0019] In the above scheme, when the difference in the upper-state population probability is less than a preset difference threshold, it indicates that the difference in the upper-state population probability of each ion in the multi-ion array under a fixed reference driving time is too small. That is, the response change caused by the laser spot under test within the spatial range covered by the current multi-ion array is not significant. This means that the effective spatial sampling points provided by the multi-ion array fail to fully cover the intensity change region of the laser spot under test from the center to the edge. If inversion is performed under this condition, the fitting between the model population probability and the measured population probability is not sensitive to changes in the center position of the spot and the beam waist parameters, which can easily lead to unstable inversion results. In contrast, this scheme reduces the ion spacing and the axial binding strength of the ion trap and increases the number of ions. This allows the reconfigured ion trap assembly to generate a multi-ion array with a denser spatial distribution and more sufficient coverage. As a result, a more discriminative upper-state population probability distribution is obtained when the laser spot rapid measurement method is executed again. This avoids the instability of fitting due to insufficient spatial coverage, improves the reliability of subsequent beam waist parameter inversion, and thus ensures the stability of rapid measurement of the laser spot under test.

[0020] This invention also provides a rapid laser spot measurement system for implementing a rapid laser spot measurement method as described in any of the preceding claims, comprising: an ion position acquisition module for acquiring the spatial position of each ion in a multi-ion array fabricated by an ion trap assembly; a maximum response ion position acquisition module for controlling a laser incident focusing assembly based on the spatial position to irradiate the multi-ion array with the laser spot for coarse response measurement, thereby acquiring the maximum response ion position; and a fixed reference driving time acquisition module for obtaining a reference Rabi frequency based on the maximum response ion position under a preset laser pulse duration sequence, and generating a fixed reference driving time based on the reference Rabi frequency. A reference driving time is defined; an upper-state population probability acquisition module is used to control the ion state preparation and manipulation components according to the fixed reference driving time to apply a test laser driving pulse with a continuous fixed reference driving time to the multi-ion array, obtain the bright and dark state results of each ion in the multi-ion array, and obtain the upper-state population probability based on the bright and dark state results; a test laser measurement module is used to acquire the spatial distribution model of the test laser and the local coupling intensity of the ion laser, and invert the spot center position, beam waist parameters and central coupling intensity of the test laser according to the local coupling intensity of the ion laser, the upper-state population probability, the fixed reference driving time and the spatial distribution model.

[0021] The present invention also provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, it implements a rapid laser spot measurement method as described in any of the preceding claims.

[0022] The above-mentioned scheme first obtains the spatial position of each ion in the multi-ion array, and then controls the laser incident focusing component to irradiate the multi-ion array with the laser spot based on the spatial position. The position corresponding to the ion with the largest response is selected as the position of the maximum response ion. In this scheme, under a preset laser pulse duration sequence, the duration of the laser driving pulse at the position of the maximum response ion is adjusted to obtain a reference Rabi frequency that reflects the local effective Rabi frequency of the ion with the largest response in the coarse measurement of the multi-ion response under the action of the current laser. A fixed reference driving time is generated based on this reference Rabi frequency. This fixed reference driving time can keep the population response at the position of the maximum response ion in a range that is sensitive to changes in local coupling strength. Subsequently, this scheme controls the ion state preparation and manipulation component to control the multi-ion array. Each ion in the array is subjected to a laser driving pulse of the test laser that lasts for the fixed reference driving time. The resulting bright and dark state results of each ion and the population probability of the upper state can improve the stability of the spot center position, beam waist parameters, and central coupling strength obtained by subsequent inversion. Moreover, this scheme does not require the acquisition of a complete Rabi oscillation curve for each spatial position, reducing the overall calibration time. Based on the local coupling strength, the population probability of the upper state, the fixed reference driving time, and the spatial distribution model, this scheme can invert the spot center position, beam waist parameters, and central coupling strength of the laser under test for calibration, achieving stable measurement of the spot center position, beam waist parameters, and central coupling strength of the laser under test. This can improve the laser spot measurement speed while ensuring the stability of laser spot measurement. Attached Figure Description

[0023] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 A flowchart illustrating the technical implementation of a rapid laser spot measurement method according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the ion beam waist measuring device provided in an embodiment of the present invention; Figure 3 This is a schematic diagram showing the relative positions of a one-dimensional multi-ion chain and the laser spot to be tested, provided in an embodiment of the present invention. Figure 4 This is a schematic diagram illustrating the initial response and fixed reference driving time acquisition of a rapid laser spot measurement method according to an embodiment of the present invention. Figure 5 This is a schematic diagram of the fitting of the population probability distribution of the multi-ion upper state and the waist parameter according to an embodiment of the present invention; Figure 6 This is a schematic diagram of a rapid laser spot measurement system architecture provided in an embodiment of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0027] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0028] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0030] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0031] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0032] Please see Figure 1 This embodiment provides a method for rapid measurement of laser spot, including the following steps: Step S1: Obtain the spatial position of each ion in the multi-ion array fabricated by the ion trap assembly; Step S2: Based on the spatial position, control the laser incident focusing component to be tested so that the laser spot to be tested irradiates the multi-ion array to perform a rough response measurement and determine the position of the maximum response ion; Step S3: Under the preset laser pulse duration sequence, obtain the reference Rabi frequency based on the position of the maximum response ion, and generate a fixed reference driving time based on the reference Rabi frequency; Step S4: Based on the fixed reference driving time, control the ion state to prepare the manipulation component to apply the test laser driving pulse with a continuous fixed reference driving time to the multi-ion array, obtain the bright and dark state results of each ion in the multi-ion array, and obtain the population probability of the upper state based on the bright and dark state results. Step S5: Obtain the spatial distribution model of the laser spot to be tested and the local coupling intensity of the ion laser, and invert the center position, beam waist parameters and center coupling intensity of the laser spot to be tested based on the local coupling intensity of the ion laser, the population probability of the upper state, the fixed reference driving time and the spatial distribution model.

[0033] The above embodiment first obtains the spatial position of each ion in the multi-ion array, and then controls the laser incident focusing component to irradiate the multi-ion array based on the spatial position so that the laser spot irradiates the multi-ion array. That is, the laser spot covers at least part of the ions in the multi-ion array without requiring the center of the laser spot to be precisely aligned with a specific ion in the multi-ion array. Thus, the position corresponding to the ion with the largest response is selected as the position of the largest response ion. In this embodiment, under a preset laser pulse duration sequence, the duration of the laser driving pulse at the position of the largest response ion is adjusted to obtain a reference Rabi frequency that reflects the local effective Rabi frequency of the ion with the largest response in the coarse measurement of the multi-ion response under the action of the current laser. A fixed reference driving time is generated based on this reference Rabi frequency. This fixed reference driving time can keep the population response at the position of the largest response ion in a range that is sensitive to changes in local coupling strength. Subsequently, this embodiment controls the ion state preparation operation. The control component applies a laser driving pulse to each ion in the multi-ion array for a continuous fixed reference driving time. The resulting bright and dark state results of each ion and the obtained upper-state population probability of each ion can improve the stability of the spot center position, beam waist parameters, and central coupling strength obtained in subsequent inversions. In this embodiment, each ion only needs to undergo population statistics to obtain the upper-state population probability under a fixed pulse driving time, without needing to collect a complete Rabi oscillation curve for each spatial location, thus reducing the overall calibration time. Based on the local coupling strength, upper-state population probability, fixed reference driving time, and spatial distribution model, this embodiment can invert the spot center position, beam waist parameters, and central coupling strength of the laser under test for calibration, achieving stable measurement of the spot center position, beam waist parameters, and central coupling strength of the laser under test. This can improve the laser spot measurement speed while ensuring the stability of laser spot measurement.

[0034] Furthermore, obtaining the spatial position of each ion in the multi-ion array prepared by the ion trap assembly includes: obtaining the fluorescence image corresponding to each ion chain in the multi-ion array prepared by the ion trap assembly; extracting the center position of the fluorescence bright spot corresponding to each ion in the ion chain in the fluorescence image; and obtaining the spatial position of each ion based on the center position of the fluorescence bright spot through mapping processing.

[0035] Furthermore, the step of controlling the laser under test incident focusing component based on the spatial position to irradiate the multi-ion array with the laser spot under test for coarse response measurement and obtaining the position of the ion with the largest response includes: controlling the laser under test incident focusing component based on the spatial position to irradiate the multi-ion array with the laser spot under test for coarse response measurement, obtaining the initial response of each ion in the multi-ion array; obtaining the spatial position of the ion corresponding to the ion with the largest initial response, and using the spatial position of the ion as the position of the ion with the largest response.

[0036] The above embodiment first controls the laser incident focusing component based on the spatial position of each ion, so that the laser spot illuminates the multi-ion array, guiding the spot to a region that covers at least some of the ions, without requiring the center of the spot to be precisely aligned with a specific ion, thus avoiding the time-consuming problem of precise alignment required in traditional methods. Subsequently, this embodiment selects the ion with the largest initial response based on the initial response distribution, and determines the position of the ion with the largest response by its corresponding spatial position. This provides a reliable basis for obtaining a fixed reference driving time, improving calibration speed while ensuring calibration stability.

[0037] Furthermore, after controlling the laser incident focusing component based on the spatial position to irradiate the multi-ion array with the laser spot for coarse response measurement and obtaining the initial response of each ion in the multi-ion array, the method further includes: confirming that the initial response of each ion is concentrated in a few adjacent ions or concentrated in a single particle, then obtaining the ion spacing, ion number, and ion trap axial binding strength of the multi-ion array; reducing the ion spacing and ion trap axial binding strength to obtain optimized ion spacing and optimized ion trap axial binding strength; increasing the ion number to obtain optimized ion number; configuring the ion trap component according to the optimized ion spacing, the optimized ion number, and the optimized ion trap axial binding strength, and the configured ion trap component is used in the next execution of the laser spot rapid measurement method.

[0038] In the above embodiments, when the initial response of each ion is concentrated in a few adjacent ions or a single ion, it indicates that the number of effective spatial sampling points or the spatial coverage provided by the current multi-ion array is insufficient relative to the scale of the laser spot to be measured. If inversion is performed directly based on this sparse sampling, it is easy to cause instability in the fitting results of the spot center position and beam waist parameters. Therefore, this embodiment obtains the ion spacing, ion number, and ion trap axial binding strength, and reduces the ion spacing and ion trap axial binding strength while increasing the ion number to obtain optimized parameters for reconfiguring the ion trap assembly. This allows the multi-ion array to provide denser spatial sampling points in the area of ​​the laser spot to be measured when the rapid laser spot measurement method is executed next time, thereby avoiding the situation of unstable fitting due to insufficient sampling density, improving the reliability of subsequent beam waist parameter inversion, and thus ensuring the stability of the laser spot measurement.

[0039] Further, the step of obtaining a reference Rabi frequency based on the position of the maximum responding ion under a preset laser pulse duration sequence, and generating a fixed reference driving time based on the reference Rabi frequency, includes: preparing a manipulation component by controlling the ion state according to different durations in the preset laser pulse duration sequence, so as to apply laser driving pulses of different durations to be tested at the position of the maximum responding ion, and obtaining a Rabi oscillation curve; fitting the Rabi oscillation curve to obtain a reference Rabi frequency, and generating a fixed reference driving time based on the reference Rabi frequency.

[0040] The above embodiment first controls the ion state preparation manipulation component to apply test laser driving pulses of different durations at the position of the maximum response ion based on different durations in a preset laser pulse duration sequence, and obtains the Rabi oscillation curve that changes with the duration. It can be seen that this embodiment only needs to obtain the Rabi oscillation curve corresponding to the position of the maximum response ion. Compared with the traditional method that requires traversing all ions in a multi-ion array, this embodiment significantly reduces the time consumed. Subsequently, this embodiment fits the Rabi oscillation curve to obtain a reference Rabi frequency reflecting the local effective coupling strength at the position of the maximum response ion under the current test laser irradiation, providing a reliable basis for subsequently determining the fixed reference driving time. Based on this reference Rabi frequency, a fixed reference driving time is generated, so that subsequent pulses of this fixed reference driving time can be applied to each ion in the multi-ion array to obtain the upper state population probability reflecting the difference in the coupling strength of each ion's spatial position, without needing to collect a complete Rabi oscillation curve for each ion separately. Based on the fixed reference driving time, this embodiment can ensure that each ion is measured within the sensitive response range, thereby ensuring the stability of the inversion results and improving the measurement speed of the test laser spot while ensuring measurement stability.

[0041] Further, the step of controlling the ion state preparation and manipulation component according to the fixed reference driving time to apply a test laser driving pulse with a continuous fixed reference driving time to the multi-ion array, obtaining the bright and dark state results of each ion in the multi-ion array, and obtaining the upper state population probability based on the bright and dark state results includes: obtaining the region of interest of each ion based on the spatial location; controlling the ion state preparation and manipulation component according to the fixed reference driving time to apply a test laser driving pulse with a continuous fixed reference driving time to the multi-ion array, obtaining the fluorescence intensity sequence corresponding to the region of interest of each ion in the multi-ion array; comparing the fluorescence intensity sequence of each ion at a preset bright state threshold to obtain the bright and dark state results; extracting the number of bright states of each ion from the bright and dark state results, and obtaining the upper state population probability based on the number of bright states.

[0042] The above embodiments obtain the region of interest (ROI) for each ion based on its spatial location, prepare a manipulation component to control the ion state according to a fixed reference driving time, apply a laser driving pulse to the multi-ion array for a duration of the fixed reference driving time, and acquire the fluorescence intensity sequence corresponding to the ROI of each ion. Since the fixed reference driving time is fixed, there is no need to set different pulse durations for different ions, thus significantly reducing the overall calibration time. After acquiring the fluorescence intensity sequence, this embodiment compares the fluorescence intensity sequence of each ion at a preset bright state threshold to obtain bright and dark state results. Then, the number of bright states for each ion is extracted from the bright and dark state results, and the upper state population probability, which can effectively suppress random fluctuations in a single measurement, is obtained based on the number of bright states. This ensures that the upper state population probability corresponding to each ion can stably reflect the difference in local coupling strength at different spatial locations, thereby ensuring the stability of subsequent laser spot measurements and improving the measurement speed.

[0043] Further, the step of obtaining the spatial distribution model of the laser under test and the local coupling intensity of the ion laser, and inverting the spot center position, beam waist parameters and center coupling intensity of the laser under test based on the local coupling intensity of the ion laser, the upper state population probability, the fixed reference driving time and the spatial distribution model, includes: obtaining the spatial distribution model of the laser under test and the local coupling intensity of the ion laser based on the spatial position and the upper state population probability; Under the fixed reference driving time, a population response model is generated based on the local coupling strength of the ion laser and the population probability of the upper state; the model population probability is obtained based on the population response model and the spatial distribution model; the measured population probability is obtained, and the measured population probability and the model population probability are fitted to construct a population probability target, and the center position of the laser spot, beam waist parameters and central coupling strength of the laser under test are obtained by inversion with the goal of minimizing the population probability target.

[0044] Further, after extracting the number of bright states for each ion from the bright and dark state results and obtaining the population probability of the upper state based on the number of bright states, the method further includes: extracting the maximum and minimum population probabilities of the upper state from the population probabilities of the upper state, and obtaining the difference between the population probabilities of the upper state based on the maximum and minimum population probabilities of the upper state; confirming that the difference between the population probabilities of the upper state is less than a preset difference threshold, then obtaining the ion spacing, ion quantity, and ion trap axial binding strength of the multi-ion array; reducing the ion spacing and the ion trap axial binding strength to obtain the population-optimized ion spacing and the population-optimized ion trap axial binding strength; increasing the ion quantity to obtain the population-optimized ion quantity; configuring the ion trap assembly based on the population-optimized ion spacing, the population-optimized ion quantity, and the population-optimized ion trap axial binding strength, and the configured ion trap assembly is used in the next execution of the laser spot rapid measurement method.

[0045] In the above embodiment, when the difference in the upper-state population probability is less than a preset difference threshold, it indicates that the difference in the upper-state population probability of each ion in the multi-ion array under a fixed reference driving time is too small. That is, the response change caused by the laser spot under test within the spatial range covered by the current multi-ion array is not significant. This means that the effective spatial sampling points provided by the multi-ion array fail to fully cover the intensity change region of the laser spot under test from the center to the edge. If inversion is performed under this condition, the fitting between the model population probability and the measured population probability is not sensitive to changes in the center position of the spot and the beam waist parameters, which can easily lead to unstable inversion results. In this embodiment, by reducing the ion spacing and the axial binding strength of the ion trap and increasing the number of ions, the reconfigured ion trap assembly can generate a multi-ion array with a denser spatial distribution and a more sufficient coverage. This allows for a more discriminative upper-state population probability distribution to be obtained in the next execution of the laser spot rapid measurement method, thereby avoiding instability in fitting due to insufficient spatial coverage, improving the reliability of subsequent beam waist parameter inversion, and ensuring the stability of the laser spot measurement.

[0046] In one embodiment, such as Figure 2 As shown, the ion beam waist measurement device includes a vacuum cavity, an ion trap assembly, a laser incident and focusing assembly, an ion state preparation and manipulation assembly, and a spatially resolved fluorescence collection and detection assembly. Figure 2 In this diagram, EMCCD stands for Electron Multiplier Coupling Device, PMT stands for Photomultiplier Tube, and PBS stands for Polarizing Beam Splitter.

[0047] The vacuum chamber provides the vacuum environment required for ion trapping. Ion trap components are housed within the vacuum chamber and are used to trap multiple ions using a radio frequency electric field and a DC control electric field, forming one-dimensional ion chains, two-dimensional ion crystals, or other spatially resolveable multi-ion arrays.

[0048] The laser under test incident focusing assembly is used to introduce the laser under test into the vacuum cavity and form a corresponding spot of the laser under test in the region where the multi-ion array is located. The laser under test can be the addressing light, global operation light, sideband driving light, cooling light, pump light, or other laser beams that require measurement of the beam waist and center position in ion trap experiments. When the laser under test acts on the multi-ion array, it will be affected by different local optical field intensities and local coupling strengths because different ions are located at different spatial positions of the spot.

[0049] An ion state preparation and manipulation component is used to prepare ions in a multi-ion array to a predetermined initial state and apply a corresponding laser driving pulse to be tested.

[0050] A spatially resolved fluorescence collection and detection assembly, which may include a fluorescence collection objective, an imaging optical path, a filter, a camera, and an image acquisition unit. This assembly is used to image the fluorescence signals of multiple ions onto the camera, forming multiple resolvable fluorescent bright spots.

[0051] In one embodiment, the multi-ion array fabricated by the ion trap assembly is a one-dimensional ion chain, which contains a total of The ions involved in the detection. For example... Figure 3 As shown, the spatial positions of each ion in the multi-ion array fabricated by the ion trap assembly are obtained. , record the The spatial positions of the ions are: .

[0052] In one embodiment, the spatial position of ions can be obtained by spatially resolved fluorescence imaging, specifically by: acquiring the fluorescence image corresponding to each ion chain in the multi-ion array, extracting the center position of the fluorescence bright spot of each ion in the ion chain, and converting the center position into the spatial position of each ion by combining the preset imaging system magnification and the preset pixel calibration factor.

[0053] Based on the spatial position of each ion, the laser beam incident focusing assembly is controlled to ensure that the laser beam spot illuminates the region where the multi-ion array is located, so that the laser beam spot at least covers a portion of the ions. It is not required that the center of the laser beam spot be precisely aligned with a specific ion, nor is it necessary to pre-determine whether the center of the spot falls on a particular ion. Therefore, as... Figure 4 As shown in (a), a preset short detection pulse is applied to the multi-ion array for coarse measurement to obtain the initial response of each ion in the multi-ion array, and the initial response distribution is obtained, where the numbers are... The initial response distribution corresponding to the ions is as follows ,like Figure 4 As shown in (b), the ion with the largest response in the initial response or the region of adjacent ions with the largest response is used as the reference ion. The spatial position of the reference ion is taken as the position of the maximum response ion.

[0054] In one embodiment, the preset laser pulse duration sequence includes various durations. The control ion state preparation manipulation component changes the duration of the laser driving pulse to be tested at the position of the ion with the maximum response, according to the different durations. This allows the measurement of a Rabi oscillation curve as a function of pulse time. The reference Rabi frequency is obtained by fitting this Rabi oscillation curve. The reference rabi frequency This represents the local effective Rabi frequency of the ion with the largest response under the current laser beam during the coarse measurement of the response of a multi-ion array.

[0055] Based on the above reference Rabi frequency Generate fixed reference driving time .like Figure 4 As shown in (c), in this embodiment, the reference driving time is fixed. The approximation is selected at the position of the ion with the maximum response. The pulse duration is as follows: ; At this point, the population response corresponding to the position of the ion with the maximum response is in a range that is more sensitive to changes in local coupling strength.

[0056] It should be noted that, if If the length is too short, the population probability of each ion will be close to the initial state, and the spatial difference will not be obvious; if... If the response is too long, the population response may enter a multi-period oscillation range, increasing the uncertainty of the inversion. Therefore, appropriate values ​​should be determined by calibrating the position of the ion with the maximum response. This can improve the reliability of subsequent beam waist parameters and spot center position inversion.

[0057] In one embodiment, based on the different spatial positions of each ion in the multi-ion array, a corresponding region of interest is defined for each ion; a multi-ion chain of duration is applied to the entire multi-ion array. When the laser driving pulse is applied to the target area, the local coupling strength experienced by different ions varies due to their different spatial positions within the target spot. Therefore, under the same fixed reference driving time, the population probabilities of the upper states for different ions also differ. At this time, the fluorescence intensity within the region of interest for each ion in the multi-ion array is statistically analyzed, and this process of acquiring fluorescence intensity is repeated. Next, the fluorescence intensity sequence corresponding to the region of interest of each ion was obtained. .

[0058] In the above embodiments, the fluorescence intensity sequence of each ion was... At the preset brightness threshold The following comparison yields the results of the bright and dark states, specifically: when At that time, the judgment of the first One ion is in a bright state; when At that time, the judgment of the first Each ion is in the dark state. The number of times each ion is in the bright state in the extracted bright and dark state results is the number of bright states. Then the first The population probability of the upper state of each ion for: .

[0059] Based on the population probability and spatial location of the upper state, the sequence of multiple ion positions and population probabilities corresponding to each ion can be obtained: .

[0060] It should be noted that when a trapped ion is in the laser field under test, the laser will drive the ion's internal state transitions, sideband transitions, Raman transitions, or other equivalent quantum transitions. If, for a given transition, the laser frequency, polarization, detuning, power stability conditions, and transition matrix elements remain unchanged, the driving intensity of the ion is mainly determined by the amplitude of the local laser electric field or the effective light intensity at the ion's location.

[0061] For the There are ions, whose spatial positions are denoted as _____. The local coupling strength or local Rabi frequency between the laser and the laser under test, i.e., the local coupling strength of the ion laser, is denoted as . .

[0062] In the case of single-photon transitions or equivalent coherent driving... This can be expressed as being proportional to the amplitude of the local electric field: ; in, For the first The local electric field amplitude at the location of each ion. And since the light intensity and electric field amplitude satisfy: ; Therefore, the local coupling intensity of ion lasers can be increased. This can be understood as being related to the square root of the local effective light intensity: .

[0063] In the case of Raman transitions, two-photon transitions, or other equivalent driving processes, the local coupling strength of ion lasers... It can be expressed as the equivalent local coupling strength determined by one or more laser fields.

[0064] It should be noted that for any transition mode, as long as the frequency, polarization, detuning and related experimental parameters of the laser under test remain stable during the measurement process, the differences between different ions mainly reflect the differences in the effective light field distribution of the laser under test at different spatial locations.

[0065] When the spatial distribution of the laser beam under test along the ion chain direction is approximately Gaussian, the first... The local coupling strength at each ion can be written as: ; in, This represents the maximum coupling strength at the center of the light spot, i.e., the central coupling strength. The center position of the laser spot to be tested. The beam waist parameter is to be measured. This shows that when different ions are located at different spatial positions within the beam spot, they experience varying ion-laser local coupling strengths. The differences are significant, and the ions closer to the center of the light spot correspond to larger... Ions farther from the center of the light spot correspond to smaller ions. Therefore, a multi-ion array can provide multiple sampling points for the spatial distribution of the laser spot under test.

[0066] At a fixed reference drive time Next, the Ion laser local coupling intensity of individual ions and the population probability of the upper state The population response relationship between the populations satisfies the following conditions, resulting in the generated population response model: in, Offset the background layout; To probe the contrast correction factor, this population response relationship indicates the local coupling strength of the ion laser. It will be transformed into a measurable population probability of the upper state through quantum state evolution over a fixed time. .

[0067] It is evident that the spatial distribution of the laser under test primarily determines the local coupling intensity of the ion laser at each ion location, i.e.: ; The local coupling strength of the ion laser further determines the fixed reference driving time. The population probability of the upper state under the given conditions, i.e.: ; Therefore, the above process can be understood as: .

[0068] This shows the spatial position of each ion Given the given information, measure the population probability of the upper states of multiple ions. This allows us to deduce the local coupling intensity of ion lasers at different spatial locations. The distribution of the light spot can be used to invert the spatial parameters of the light spot.

[0069] like Figure 5 As shown, Figure 5 middle To fit the inverted waist parameters ,and Figure 5 The solid discrete points in the diagram represent the population probabilities of the upper states measured at different ion spatial locations. : It reflects the effective spatial distribution of the laser under test in the direction of the ion chain, and is regarded as a spatial distribution model.

[0070] The spatial distribution model is compared with the fixed reference driving time. By combining the population response models, we can obtain the population probabilities of the models. : ; Among them, the parameters to be inverted include the center position of the light spot. Waist-cinching parameters and central coupling strength .like Figure 5 As shown, the measured population probability is obtained. and the measured population probability and model population probability The objective of fitting and constructing the population probability is: ; With the goal of minimizing the population probability, the center position of the laser spot is obtained by inversion using least squares fitting, weighted least squares fitting, maximum likelihood estimation, or Bayesian estimation methods. Waist-cinching parameters and central coupling strength Among them, the center position of the light spot Primarily determined by the location of the maximum value of the population probability distribution and its left-right asymmetry; waist parameter It is mainly determined by the rate at which the population probability decays with spatial location; the central coupling strength It is mainly determined by the overall population response magnitude.

[0071] It should be noted that there is a matching relationship between the spot size of the laser beam under test and the inter-ion spacing, the number of ions, and the total length of the ion array. The ions themselves can be approximated as point-like quantum probes, the inter-ion spacing determines the spatial sampling density, and the number of ions and the total length of the array determine the spatial sampling range.

[0072] Let the typical spacing between adjacent ions in a multi-ion array be... The total length of the multi-ion array is The beam waist parameters of the laser to be tested are: .when When the spot size of the laser beam under test is much smaller than the distance between adjacent ions, only one or a few adjacent ions may produce a significant response, resulting in sparse spatial sampling and reduced stability of the beam waist parameter fitting; when When the spot size of the laser to be tested is much larger than the total length of the ion array, the local coupling strength at each ion is relatively small, and the population probability distribution of multiple ions tends to be flat, which will reduce the sensitivity of beam waist parameter inversion.

[0073] Therefore, in one embodiment, the maximum upper-state population probability is extracted from the upper-state population probability. and minimum upper state population probability The difference between the population probabilities of the upper state is obtained based on the maximum and minimum upper state population probabilities. If the difference in population probability of the above state Less than the preset difference threshold ,Right now: ; The ion spacing, ion number, and ion trap axial binding strength of the multi-ion array are obtained; the ion spacing and the ion trap axial binding strength are reduced to obtain population-optimized ion spacing and population-optimized ion trap axial binding strength; the ion number is increased to obtain population-optimized ion number; the ion trap assembly is configured according to the population-optimized ion spacing, population-optimized ion number, and population-optimized ion trap axial binding strength, and the configured ion trap assembly is used in the next execution of the laser spot rapid measurement method.

[0074] It should be noted that the above embodiments can also expand the spatial sampling range by reducing the axial confinement frequency, moving the ion array, or performing segmented sampling.

[0075] In one embodiment, if the initial response of each ion is concentrated in a few adjacent ions or in a single particle, the ion spacing, ion number, and axial binding strength of the ion trap of the multi-ion array are obtained. The ion spacing and the axial binding strength of the ion trap are reduced to obtain optimized ion spacing and optimized ion trap axial binding strength. The ion number is increased to obtain optimized ion number. The ion trap assembly is configured according to the optimized ion spacing, the optimized ion number, and the optimized ion trap axial binding strength. The configured ion trap assembly is used in the next execution of the laser spot rapid measurement method.

[0076] It should be noted that the above embodiments can also expand the spatial sampling density by moving the ion array, moving the spot to be measured, or repeating the fixed reference driving time measurement at a small number of different relative positions.

[0077] The above embodiments can avoid performing unstable fitting directly when the sampling density is insufficient or the spatial coverage is insufficient, thereby improving the reliability and applicability of waist parameter measurement.

[0078] Please see Figure 6This embodiment also provides a rapid laser spot measurement system for implementing any of the above-mentioned rapid laser spot measurement methods, including: an ion position acquisition module for acquiring the spatial position of each ion in a multi-ion array prepared by an ion trap assembly; a maximum response ion position acquisition module for controlling the laser incident focusing assembly under test based on the spatial position so that the spot of the laser under test irradiates the multi-ion array for coarse response measurement, and acquiring the maximum response ion position; and a fixed reference driving time acquisition module for obtaining a reference Rabi frequency based on the maximum response ion position under a preset laser pulse duration sequence, and generating a fixed parameter based on the reference Rabi frequency. The system includes a driving time and an upper-state population probability acquisition module, which controls the ion state preparation and manipulation components according to the fixed reference driving time to apply a continuous fixed reference driving time laser driving pulse to the multi-ion array, obtains the bright and dark state results of each ion in the multi-ion array, and obtains the upper-state population probability based on the bright and dark state results; and a laser measurement module, which obtains the spatial distribution model of the laser under test and the local coupling intensity of the ion laser, and inverts the spot center position, beam waist parameters, and center coupling intensity of the laser under test based on the local coupling intensity of the ion laser, the upper-state population probability, the fixed reference driving time, and the spatial distribution model.

[0079] It is understood that the above system embodiments correspond to the method embodiments of the present invention, and can implement the laser spot rapid measurement method provided by any of the above method embodiments of the present invention.

[0080] It should be noted that the system embodiments described above are merely illustrative, and some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the system embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0081] The present invention also provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, it implements any of the above-described rapid laser spot measurement methods.

[0082] The terminal device may be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0083] The above embodiment first obtains the spatial position of each ion in the multi-ion array, and then controls the laser incident focusing component to irradiate the multi-ion array with the laser spot based on the spatial position. The position corresponding to the ion with the largest response is selected as the position of the largest response ion. In this embodiment, under a preset laser pulse duration sequence, the duration of the laser driving pulse at the position of the largest response ion is adjusted to obtain a reference Rabi frequency that reflects the local effective Rabi frequency of the ion with the largest response in the coarse measurement of the multi-ion response under the action of the current laser. A fixed reference driving time is generated based on the reference Rabi frequency. This fixed reference driving time can keep the population response at the position of the largest response ion in a range that is sensitive to changes in local coupling strength. Subsequently, this embodiment controls the ion state preparation and manipulation component to control the multi-ion array. Each ion in the array is subjected to a laser driving pulse of the test state for a duration of the fixed reference driving time. The resulting bright and dark state results of each ion and the population probability of the upper state can improve the stability of the spot center position, beam waist parameters, and central coupling strength obtained by subsequent inversion. Furthermore, this embodiment does not require the acquisition of complete Rabi oscillation curves for each spatial location, reducing the overall calibration time. Based on the local coupling strength, the population probability of the upper state, the fixed reference driving time, and the spatial distribution model, this embodiment can invert the spot center position, beam waist parameters, and central coupling strength of the laser under test for calibration, achieving stable measurement of the spot center position, beam waist parameters, and central coupling strength of the laser under test. This can improve the laser spot measurement speed while ensuring the stability of laser spot measurement.

[0084] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A rapid laser spot measurement method, applied to an ion beam waist measurement device including an ion state preparation and manipulation component, an ion trap component, and a laser incident focusing component, characterized in that, Includes the following steps: Obtain the spatial position of each ion in the multi-ion array fabricated by the ion trap assembly; Based on the spatial position, the laser under test incident focusing component is controlled so that the spot of the laser under test irradiates the multi-ion array to perform a rough response measurement and obtain the position of the maximum response ion. Under a preset laser pulse duration sequence, a reference Rabi frequency is obtained based on the position of the maximum response ion, and a fixed reference driving time is generated based on the reference Rabi frequency; The control component is prepared according to the fixed reference driving time to apply a laser driving pulse of the test to a multi-ion array with a continuous fixed reference driving time, obtain the bright and dark state results of each ion in the multi-ion array, and obtain the population probability of the upper state based on the bright and dark state results. The spatial distribution model of the laser under test and the local coupling intensity of the ion laser are obtained. Based on the local coupling intensity of the ion laser, the population probability of the upper state, the fixed reference driving time, and the spatial distribution model, the spot center position, beam waist parameters, and central coupling intensity of the laser under test are obtained by inversion.

2. The method for rapid measurement of laser spot as described in claim 1, characterized in that, The acquisition of the spatial position of each ion in the multi-ion array prepared by the ion trap assembly includes: Obtain fluorescence images of each ion chain in the multi-ion array fabricated by the ion trap assembly; Extract the center position of each ion in the ion chain corresponding to the fluorescent bright spot in the fluorescence image; The spatial position of each ion is obtained by mapping the center position of the fluorescent bright spot.

3. The method for rapid measurement of laser spot as described in claim 2, characterized in that, The step of controlling the laser incident focusing component based on the spatial position to irradiate the multi-ion array with the laser spot for coarse response measurement and obtaining the position of the ion with the maximum response includes: Based on the spatial position control of the laser under test incident focusing component, the spot of the laser under test is used to irradiate the multi-ion array for coarse response measurement, and the initial response of each ion in the multi-ion array is obtained. Obtain the spatial position of the ion with the largest initial response, and use the spatial position of the ion as the position of the ion with the largest response.

4. The method for rapid measurement of laser spot as described in claim 3, characterized in that, After controlling the laser incident focusing component based on the spatial position to irradiate the multi-ion array with the laser spot for coarse response measurement and obtaining the initial response of each ion in the multi-ion array, the method further includes: If the initial response of each ion is confirmed to be concentrated in a few adjacent ions or concentrated in a single particle, then the ion spacing, ion number and ion trap axial binding strength of the multi-ion array are obtained. The ion spacing and the axial binding strength of the ion trap are reduced to obtain optimized ion spacing and optimized axial binding strength of the ion trap. An optimized number of ions is obtained by increasing the number of ions. An ion trap assembly is configured based on the optimized ion spacing, the optimized ion quantity, and the optimized ion trap axial binding strength. This configured ion trap assembly is then used in the next execution of the rapid laser spot measurement method.

5. The method for rapid measurement of laser spot as described in claim 3, characterized in that, The step of obtaining a reference Rabi frequency based on the position of the maximum responding ion under a preset laser pulse duration sequence, and generating a fixed reference driving time based on the reference Rabi frequency, includes: A manipulation component is prepared by controlling the ion state according to different durations in a preset laser pulse duration sequence, so as to apply the laser driving pulse to be tested for different durations at the position of the maximum response ion and obtain the Rabi oscillation curve; The reference Rabi frequency is obtained by fitting the Rabi oscillation curve, and a fixed reference drive time is generated based on the reference Rabi frequency.

6. The method for rapid measurement of laser spot as described in claim 1, characterized in that, The process of preparing and manipulating ion states based on the fixed reference driving time to apply a laser driving pulse of a continuous fixed reference driving time to a multi-ion array, obtaining the bright and dark state results of each ion in the multi-ion array, and obtaining the population probability of the upper state based on the bright and dark state results includes: The region of interest for each ion is obtained based on the spatial location; Based on the fixed reference driving time, a control component is prepared to apply a laser driving pulse of the test to a multi-ion array with a continuous fixed reference driving time, and to obtain the fluorescence intensity sequence corresponding to the region of interest of each ion in the multi-ion array. The fluorescence intensity sequences of each ion are compared at a preset bright state threshold to obtain bright and dark state results; The number of bright states for each ion is extracted from the bright and dark state results, and the population probability of the upper state is obtained based on the number of bright states.

7. The method for rapid measurement of laser spot as described in claim 6, characterized in that, The process of acquiring the spatial distribution model of the laser under test and the local coupling strength of the ion laser, and inverting the spot center position, beam waist parameters, and central coupling strength of the laser under test based on the local coupling strength of the ion laser, the population probability of the upper state, the fixed reference driving time, and the spatial distribution model, includes: The spatial distribution model of the laser to be tested and the local coupling strength of the ion laser are obtained based on the spatial location and the population probability of the upper state. Under the fixed reference driving time, a population response model is generated based on the ion laser local coupling strength and the upper state population probability; The population probability of the model is obtained based on the population response model and the spatial distribution model. The measured population probability is obtained, and the measured population probability and the model population probability are fitted to construct a population probability target. The center position of the laser spot, the beam waist parameter and the center coupling strength of the laser under test are obtained by inversion with the goal of minimizing the population probability target.

8. The method for rapid measurement of laser spot as described in claim 6, characterized in that, After extracting the number of bright states for each ion from the bright and dark state results and obtaining the population probability of the upper state based on the number of bright states, the method further includes: Extract the maximum and minimum upper-state population probabilities from the upper-state population probabilities, and obtain the difference between the upper-state population probabilities based on the maximum and minimum upper-state population probabilities. If the population probability difference of the upper state is confirmed to be less than a preset difference threshold, then the ion spacing, ion number and ion trap axial binding strength of the multi-ion array are obtained. By reducing the ion spacing and the axial binding strength of the ion trap, population-optimized ion spacing and population-optimized axial binding strength of the ion trap are obtained. The population-optimized ion number is obtained by increasing the number of the ions. An ion trap assembly is configured based on the population-optimized ion spacing, the population-optimized ion number, and the population-optimized ion trap axial confinement strength. This configured ion trap assembly is then used in the next execution of the rapid laser spot measurement method.

9. A rapid laser spot measurement system, characterized in that, A method for rapidly measuring laser spot as described in any one of claims 1 to 8, comprising: The ion position acquisition module is used to acquire the spatial position of each ion in the multi-ion array fabricated by the ion trap assembly; The maximum response ion position acquisition module is used to control the laser under test incident focusing component based on the spatial position so that the spot of the laser under test irradiates the multi-ion array for coarse response measurement and to acquire the position of the maximum response ion. A fixed reference driving time acquisition module is used to obtain a reference Rabi frequency based on the position of the maximum response ion under a preset laser pulse duration sequence, and generate a fixed reference driving time based on the reference Rabi frequency; The upper state population probability acquisition module is used to control the ion state preparation and manipulation components according to the fixed reference driving time to apply a test laser driving pulse with a continuous fixed reference driving time to the multi-ion array, obtain the bright and dark state results of each ion in the multi-ion array, and obtain the upper state population probability based on the bright and dark state results. The laser under test measurement module is used to acquire the spatial distribution model of the laser under test and the local coupling intensity of the ion laser, and to invert the spot center position, beam waist parameters and central coupling intensity of the laser under test based on the local coupling intensity of the ion laser, the population probability of the upper state, the fixed reference driving time and the spatial distribution model.

10. A terminal device, characterized in that, The method includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, it implements a rapid laser spot measurement method as described in any one of claims 1 to 8.

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