CN110108302B - Method for improving atom group polishing precision - Google Patents
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Abstract
The application discloses method for improving accuracy of polishing of atomic group is applicable to cold atom interferometer, including magnetic trap and sensitization camera in the cold atom interferometer, include: step 1, when cooling light of a magneto-optical trap is turned on and a gradient magnetic field is turned off, a background image of the magneto-optical trap is acquired by using a photosensitive camera; step 2, utilizing a photosensitive camera to successively open and trap the cold radicals under the cooling light and the gradient magnetic field to obtain a plurality of target images of the magnetic light trap; step 3, calculating the trapping position of the cold atomic group for each target image by adopting a differential algorithm according to the background image and the plurality of target images; and 4, calculating coordinate jitter errors of the trapping positions in the multiple target images, and calculating a first adjustment coefficient of the magneto-optical trap according to the coordinate jitter errors. Through the technical scheme in the application, the accuracy of determining the cold atom group trapping position is improved, and the interference effect of the cold atom interferometer and the accuracy of parameter adjustment are optimized.
Description
Technical Field
The application relates to the technical field of cold atom interference gyroscopes, in particular to a method for improving the polishing precision of atomic group pairs.
Background
The resolution and the measurement precision of the atomic gyroscope are greatly improved compared with an optical gyroscope. Currently, there are two main types of such atomic gyroscopes: a hot atom beam gyroscope and a cold atom gyroscope. The cold atom gyroscope needs to reduce the cooling temperature of the atomic group so as to improve the stability of the trapping position of the cold atomic group, adjust the pointing precision of the cold atomic group pair throwing and the speed of the atomic group pair throwing, and further improve the detection performance of the cold atom gyroscope.
In the actual working process, the initial position of the cold atomic group before being cast each time is different due to the slight changes of factors such as the number of caged atoms, the polarization of caged light, the frequency of caged light, the intensity of caged magnetic field and the like, and the direction of the cold atomic group cast each time is also influenced by the factors. The deviation of the initial position and the casting direction can cause the repeatability of the atom interference effect to be poor, and the detection error of the gyroscope is increased.
In the prior art, in order to monitor the initial position of the cold radical, a high-resolution camera can be used to photograph the cold radical in the imprisoned state, and then the change of the position of the cold radical is analyzed according to a related algorithm of image processing. In this process, on one hand, when determining the centroid of the cold radical, the cold radical is only treated as a common point source light spot, and the attenuation of the brightness of the cold radical is not considered, so that the centroid location is deviated. On the other hand, when the cold atomic group flight deviation is judged, the cold atomic group projection deviation is indirectly deduced according to the interference fringes and the fluorescence signal change information in the detection stage after interference, and the deviation judgment method is lack of monitoring the middle flight process of the cold atomic group, so that the deviation of the flight process and the reason causing the deviation are difficult to accurately judge, and the deviation is not beneficial to reduction.
Disclosure of Invention
The purpose of this application lies in: the accuracy of determining the cold atom group trapping position is improved, and the interference effect of the cold atom interferometer and the accuracy of parameter adjustment are optimized.
The technical scheme of the application is as follows: the method for improving the precision of the atomic group polishing is suitable for a cold atom interferometer, the cold atom interferometer comprises a magnetic light trap and a photosensitive camera, and a shooting area of the photosensitive camera is right opposite to the magnetic light trap, and the method comprises the following steps: step 1, when cooling light of a magneto-optical trap is turned on and a gradient magnetic field is turned off, a background image of the magneto-optical trap is acquired by using a photosensitive camera; step 2, utilizing a photosensitive camera to successively open and trap the cold radicals under the cooling light and the gradient magnetic field to obtain a plurality of target images of the magneto-optical trap; step 3, calculating the trapping position of the cold atomic group for each target image by adopting a differential algorithm according to the background image and the plurality of target images, wherein the trapping position is the position where the magneto-optical trap traps the cold atomic groups; step 4, calculating coordinate jitter errors of the trapping positions in the multiple target images, and calculating a first adjustment coefficient of the magneto-optical trap according to the coordinate jitter errors, wherein the first adjustment coefficient comprises a first optical path coefficient and a first magnetic field coefficient, and a calculation formula of the first adjustment coefficient f (-) is as follows:
σ pos (u)＝f(P(u),A(u),F(u),C(u),G(u)),u＝1,2,3…U
in the formula, σ pos (u) is coordinate dithering error corresponding to the u-th target image, P (u) is light intensity of cooling light corresponding to the u-th target image, A (u) is casting angle of corresponding cold atomic group, F (u) is corresponding cooling light frequency, C (u) is corresponding magnetic field current intensity, and G (u) is corresponding magnetic field gradient.
In any one of the above technical solutions, further, step 3 specifically includes: step 31, sequentially selecting a target image according to the background image and the sequence of the target image, calculating the pixel revision value of a pixel point in the target image by adopting a difference algorithm, and generating a revised image, wherein the calculation formula of the pixel revision value is as follows:
in the formula, P t For modifying the value, P, of a pixel 0 Is the pixel value, P, of a pixel point in the background image p The pixel values of pixel points in the pth target image are p =1,2, \ 8230;, N;
step 32, sequentially selecting pixel points with the largest pixel values in the revised image, recording the pixel points as central points, and determining an image area ROI of the revised image by taking the selected central points as the centers, wherein the image area comprises all light spots; and step 33, calculating the center of mass of the light spots in the ROI of the image area according to the pixel values in the ROI of the image area, and recording the center of mass of the light spots as the caged position of the target image.
In any one of the above technical solutions, further, step 33 specifically includes: step 331, using the spot centroid (x) 0 ,y 0 ) Constructing a transverse bisector and a longitudinal bisector of the image region ROI at equal intervals for a coordinate origin, wherein the number K of the transverse bisector and the longitudinal bisector is an odd number, and the (K-1)/2 th transverse bisector and the (K-1)/2 th longitudinal bisector pass through the centroid of the light spot; step 332, calculating any one of the image regions ROI by utilizing a Gaussian fitting model according to the pixel values in the image regions ROIThe method comprises the following steps of calculating the transverse center coordinates on the transverse bisector and calculating the longitudinal center coordinates on any longitudinal bisector, wherein the calculation formula of the Gaussian fitting model is as follows:
in the formula, B is a pixel value, w is a coordinate value of a transverse bisector or a longitudinal bisector, a is an amplitude, B is a transverse center coordinate or a longitudinal center coordinate, and c is a fitting radius; and step 333, generating a light spot center according to the average value of the transverse center coordinates and the average value of the longitudinal center coordinates, and recording the light spot center as the imprisoned position.
In any of the above technical solutions, further, the method further includes: step 5, acquiring a projection image of the cold atomic group one by one after the cold atomic group is trapped, calculating a position coordinate of the cold atomic group in the projection process, and fitting and generating a projection track of the cold atomic group in the projection process according to the position coordinate; step 6, calculating the track coincidence degree of the casting track, and calculating a second adjustment coefficient of the magneto-optical trap according to the track coincidence degree, wherein the second adjustment coefficient comprises a second light path coefficient and a second magnetic field coefficient, and the calculation formula of the second adjustment coefficient g (-) is as follows:
g(Δ(u′),T1(u′),T2(u′))＝σ diff (u′),u′＝1,2,3…U′
in the formula, σ diff (u ') is the track coincidence degree of the u ' th cast track, delta (u ') is the corresponding cooling light frequency detuning amount, T1 (u ') is the corresponding cooling light illumination time, and T2 (u ') is the corresponding magnetic field action time.
The beneficial effect of this application is:
because the positioning precision of the initial position of the atomic group is improved, the flying direction, the flying speed and the diffusion speed of the atomic group can be calculated according to the positions of the atomic group at different moments in the flying process, the stability of the trapping position of the atomic group, the pointing precision of the atomic group opposite throwing and the consistency of the atomic group opposite throwing speed can be accurately measured by the technical scheme, and the performance of the gyroscope is further improved. And by controlling the photographing time of the camera, the measurement result can be obtained within a flight period, and the experiment efficiency is greatly improved. In addition, the technical scheme of the application can also carry out feedback control on the optical path and the magnetic field system in real time according to the measurement result, and adjust and optimize the projecting process of the atomic groups.
Drawings
The advantages of the above and/or additional aspects of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a schematic flow diagram of a method of improving accuracy of radical pair polishing according to one embodiment of the present application;
FIG. 2 is a graph simulation diagram of a target image and a revised image according to one embodiment of the present application;
FIG. 3 is a Gaussian curve simulation plot according to an embodiment of the application;
FIG. 4 is a schematic illustration of a bisector according to one embodiment of the present application;
FIG. 5 is a bisector pixel value simulation graph according to one embodiment of the present application;
FIG. 6 is a graph of light intensity as a function of jitter error according to one embodiment of the present application.
Detailed Description
In order that the above objects, features and advantages of the present application can be more clearly understood, the present application will be described in further detail with reference to the accompanying drawings and detailed description. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application, however, the present application may be practiced in other ways than those described herein, and therefore the scope of the present application is not limited by the specific embodiments disclosed below.
As shown in fig. 1, this embodiment provides a method for improving the polishing precision of a radical pair, which is suitable for a cold atom interferometer, where the cold atom interferometer includes a magnetic light trap and a photosensitive camera, an imaging region of the photosensitive camera is right opposite to the magnetic light trap, the two ends of the cold atom interferometer are provided with the magnetic light trap, the magnetic light trap is generally composed of a three-dimensional space standing wave field and a gradient magnetic field, where the three-dimensional space standing wave field is formed by three pairs (six beams) of negative detuning opposing laser beams that are perpendicular to each other two by two and have a specific circular polarization state, and the opposing laser beams are recorded as cooling light (in which pumping back light is coupled), and the gradient magnetic field is generated by a pair of reverse helmholtz coils. When the six beams of cooling light and the gradient magnetic field are started, a trapping region can be formed in the magneto-optical trap, atoms can be trapped in the center of the trapping region to form cold radicals, and the position where the cold radicals are formed is the initial position of the cold radicals. And then the cold radicals trapped in the magneto-optical traps at the two ends are oppositely thrown so as to realize the interference of the cold radicals. The initial position of the cold radical is directly photographed by a photographic camera and interfered by cooling light in a magneto-optical trap, and therefore, the method comprises:
step 1, when cooling light of a magneto-optical trap is turned on and a gradient magnetic field is turned off, namely before the magneto-optical trap traps the cold radicals, a background image of the magneto-optical trap is acquired by using a photosensitive camera, at this time, the cold radicals are not formed in the magneto-optical trap, but the influence of the cooling light is exerted, a part of area in the magneto-optical trap is still illuminated by the cooling light, and the illuminated area of the part of area interferes with the determination of the initial position (trapping position) of the cold radicals.
specifically, in step 2, under the condition that system parameters of the cold atom interferometer are not changed, considering that parameters such as the initial position, the shape, the size and the brightness of the cold atom group formed in the magneto-optical trap by the cold atom group fluctuate, a cooling light and a gradient magnetic field are turned on, the cold atom group is trapped in the magneto-optical trap, after the cold atom group is trapped, a target image before the cold atom group is ejected in the magneto-optical trap is obtained by using a photosensitive camera, and after the cold atom group is ejected, the above process is repeated again to obtain a target image of the next magneto-optical trap, that is, a plurality of target images after the cold atom group is formed in the magneto-optical trap and before the cold atom group is ejected are obtained.
further, in the step 3, the method specifically includes:
step 31, sequentially selecting a target image according to the background image and the sequence of the target image, calculating the pixel revision value of the pixel points in the target image by adopting a difference algorithm, and generating a revised image, wherein the calculation formula of the pixel revision value is as follows:
in the formula, P t For pixel revision value, P 0 Is the pixel value, P, of a pixel point in the background image p The pixel values of the pixel points in the p-th target image are p =1,2, \8230;, N.
Specifically, it is set that the obtained p-th target image has a large number of interference points 201 with high brightness due to interference of cooling light as shown in fig. 2 (a), and a revised image of the p-th target image after revision can be obtained by the above-mentioned revision of the pixel values as shown in fig. 2 (b).
And 32, sequentially selecting pixel points with the maximum pixel values in the revised image, recording the pixel points as central points, and determining an image region ROI of the revised image by taking the selected central points as the centers, wherein the image region comprises all light spots, and the size of the image region ROI is mxn.
In an implementation manner of this embodiment, a specific method for determining the image region ROI is as follows:
taking any revised image as a unit, selecting a pixel point with the largest pixel value in the revised image, recording the pixel point as a central point, recording the central point as the center of a light spot selecting frame, adjusting the size of the light spot selecting frame according to the size of the pixel value in the revised image, generating the light spot selecting frame, enabling the light spot selecting frame to contain all light spots in the revised image, and recording the generated light spot selecting frame as an image area ROI of the revised image, wherein the light spot selecting frame can be one of a rectangle, a square, an oval and a circle, and in the embodiment, the rectangle is selected as the light spot selecting frame.
In another implementation manner in this embodiment, a specific method for determining the image region ROI is as follows:
the pixel value threshold is set in units of any one of the revised images. Selecting a pixel point with the maximum pixel value in the revised image, recording the pixel point as a central point, recording the central point as the center of a light spot selecting frame, selecting a pixel point with the pixel value more than or equal to the pixel value threshold according to the size of the pixel value in the revised image and the set pixel value threshold, recording the selected pixel point as a light spot, adjusting the size of the light spot selecting frame to ensure that the light spot selecting frame comprises all light spots in the revised image, generating the light spot selecting frame, and recording the generated light spot selecting frame as an image area ROI of the revised image. The light spot picking frame may be one of a rectangle, a square, an ellipse, and a circle, and the rectangle is selected as the light spot picking frame in this embodiment.
Step 33, calculating the light spot mass center of the ROI of the image region according to the pixel value in the ROI of the image region, and recording the light spot mass center as the imprisoned position of the target image;
specifically, in this step 33, the spot centroid (x) 0 ,y 0 ) The calculation formula of (2) is as follows:
in the formula, F (i, j) is the pixel value of the pixel point (i, j) in the image region ROI, and m and n are the width and height of the image region ROI, respectively.
By analyzing the pixel values of the pixel points on the same abscissa or the same ordinate in the image region ROI and performing a large amount of data statistics, it is found that, for the same abscissa (ordinate), as the ordinate (abscissa) of the same coordinate gradually increases (decreases), the change of the pixel values of the same coordinate conforms to gaussian distribution, as shown in fig. 3 (a), therefore, an attempt is made to use a gaussian fitting model, on the basis of the centroid of the light spot, the confinement position of the image region ROI is revised, and then the parameters of the cold atom interferometer are adjusted through the revised confinement position, so that the detection error of the cold atom interferometer is further reduced, wherein the revised luminance curve of the image region ROI is shown in fig. 3 (b).
Therefore, in a preferred implementation manner of this embodiment, the step 33 further includes:
step 331, using the spot centroid (x) 0 ,y 0 ) Constructing a transverse bisector and a longitudinal bisector of the image region ROI at equal intervals for a coordinate origin, wherein the number K of the transverse bisector and the longitudinal bisector is an odd number, and the (K-1)/2 th transverse bisector and the (K-1)/2 th longitudinal bisector pass through the centroid of the light spot;
step 332, calculating the transverse center coordinates on any one transverse bisector according to the pixel values in the image region ROI by using a Gaussian fitting model, an
And calculating the longitudinal center coordinate on any longitudinal bisector, wherein the calculation formula of the Gaussian fitting model is as follows:
in the formula, B is a pixel value, w is a coordinate value of a transverse bisector or a longitudinal bisector, a is an amplitude, B is a transverse center coordinate or a longitudinal center coordinate, and c is a fitting radius;
and step 333, generating a light spot center according to the average value of the transverse center coordinates and the average value of the longitudinal center coordinates, and recording the light spot center as the imprisoned position.
Specifically, in the present embodiment, the number of the lateral bisectors and the number of the longitudinal bisectors are set to 7, respectively, and the bisectors are formed as shown in fig. 4,i.e. taken through the origin of coordinates (x) 0 ,y 0 ) The transverse line (light spot mass center), the three equally spaced transverse lines above the origin of coordinates and the three equally spaced transverse lines below the origin of coordinates, which total 7 transverse bisectors, and the total 7 longitudinal bisectors are taken from the vertical line passing through the origin of coordinates (light spot mass center), the three equally spaced vertical lines to the right of the origin of coordinates and the three equally spaced vertical lines to the left of the origin of coordinates.
Taking the transverse bisectors as an example, in the image region ROI, the range of the abscissa i of the transverse bisector is 1,2, \ 8230;, m, for each transverse bisector, any one determined abscissa i corresponds to a fixed pixel value B, so that the corresponding luminance curve can be obtained by the gaussian fitting model, as shown in fig. 5, and therefore, the transverse center coordinates B1, B2, \ 8230;, B7 of the 7 transverse bisectors can be determined, and the average value thereof is recorded as the abscissa x of the imprisoned position center . Similarly, the ordinate y of the imprisoning position can be calculated center . In summary, the coordinates of the imprisoning location are (x) center ,y center )。
Step 4, calculating coordinate dithering errors of the imprisoned positions in the multiple target images, and calculating a first adjustment coefficient of the magneto-optical trap according to the coordinate dithering errors, wherein the first adjustment coefficient comprises a first light path coefficient and a first magnetic field coefficient, and a calculation formula of the first adjustment coefficient f (-) is as follows:
σ pos (u)＝f(P(u),A(u),F(u),C(u),G(u)),u＝1,2,3…U
in the formula, σ pos (u) is a coordinate dithering error corresponding to the u-th target image, P (u) is a light intensity of the cooling light corresponding to the u-th target image, a (u) is a casting angle of the corresponding cold atomic group, F (u) is a corresponding cooling light frequency, C (u) is a corresponding magnetic field current intensity, and G (u) is a corresponding magnetic field gradient, wherein the first optical path coefficient comprises the light intensity P (u) and the cooling light frequency F (u) of the cooling light, and the first magnetic field coefficient comprises the casting angle a (u) and the magnetic field current intensity C (u) of the cold atomic group.
Specifically, in this step 4, the coordinate dithering error σ pos The calculation formula of (2) is as follows:
in the formula, σ x ＝std(x center ) Is the abscissa x center Standard deviation in x-direction, σ y ＝std(y center ) Is the ordinate y center Standard deviation in the y-direction.
In this embodiment, the coordinate dithering error σ is determined using a progressive scan method pos The smallest parameter combination is designated as the first adjustment factor. Taking the light intensity P (U) as an example, the calculation of the first adjustment coefficient is explained, the rest coefficients in the first adjustment coefficient are fixed and unchanged, the light intensity P (U) is sequentially increased, after U target images are obtained, the light intensity P (U) and the coordinate jitter error sigma are constructed pos As shown in fig. 6. By analyzing the above function, the minimum coordinate jitter error sigma can be obtained pos Lower, the corresponding light intensity P. Further, by repeating the scanning, the coordinate dithering error sigma is obtained pos The smallest coefficient combination determines the first adjustment coefficient.
It should be noted that, in the actual operation, some coefficients (such as the cooling light frequency F) can be automatically scanned by means of a computer program, and some coefficients (such as the cast angle a) depend on manually changing the scanning value.
Further, the method further comprises:
step 5, acquiring a projection image of the cold atomic group one by one after the cold atomic group is trapped, calculating a position coordinate of the cold atomic group in the projection process, and fitting and generating a projection track of the cold atomic group in the projection process according to the position coordinate;
specifically, in step 5, the flight duration of the cold atomic group in the cold atomic group interferometer is set to be 20ms by the image acquisition method, the cold atomic group is photographed at intervals of 1ms, the position coordinates of the cold atomic group in the casting process are calculated by the methods in steps 1 to 8, and then the position coordinates of the cold atomic group acquired in 20ms are fitted to generate the casting trajectory.
Step 6, calculating the track coincidence degree of the casting track, and calculating a second adjustment coefficient of the magneto-optical trap according to the track coincidence degree, wherein the second adjustment coefficient comprises a second optical path coefficient and a second magnetic field coefficient, and the calculation formula of the second adjustment coefficient g (-) is as follows:
g(Δ(u′),T1(u′),T2(u′))＝σ diff (u′),u′＝1,2,3…U′
in the formula, σ diff (u ') is a trajectory coincidence degree of the u' th casting trajectory, Δ (u ') is a corresponding cooling light frequency detuning amount, T1 (u') is a corresponding cooling light illumination time, and T2 (u ') is a corresponding magnetic field application time, wherein the second optical path coefficient includes the cooling light frequency detuning amount Δ (u') and the cooling light illumination time T1 (u '), and the second magnetic field coefficient includes the magnetic field application time T2 (u').
Specifically, in this step 6, the trajectory of the cold atom group projection is fitted with a parabola. In theory, the vertex of the parabola is the central position of the interference region, namely the action position corresponding to the second beam of Raman light in the cold atom interferometer. Because of the mechanism of ejecting cold atoms in the cold atom interferometer, that is, two groups of cold atoms are ejected toward each other, the distance between the vertices of two parabolas, namely, between the vertex and the vertex is defined as the trajectory distance, that is, the trajectory distance diff = the trajectory (a) -the trajectory (B). In the cold atomic group ejection process, a plurality of ejection tests are required, and the generated pairs of ejection tracks have jitter, so that the jitter standard difference of the track distances diff between the pairs of ejection tracks is recorded as the track contact ratio sigma diff Namely, for any one casting track, the track coincidence degree can be obtained.
Determining track contact ratio sigma by using successive scanning method diff (u') in the case of the optimum, the corresponding parameter combination is written as a second adjustment coefficient.
The technical solution of the present application is described in detail above with reference to the accompanying drawings, and the present application provides a method for improving the precision of radical pair polishing, which is suitable for a cold atom interferometer, wherein the cold atom interferometer comprises a magnetic light trap and a photosensitive camera, and comprises: step 1, when cooling light of a magneto-optical trap is turned on and a gradient magnetic field is turned off, a background image of the magneto-optical trap is obtained by using a photosensitive camera; step 2, utilizing a photosensitive camera to successively open and trap the cold radicals under the cooling light and the gradient magnetic field to obtain a plurality of target images of the magneto-optical trap; step 3, calculating the trapping position of the cold atomic group for each target image by adopting a differential algorithm according to the background image and the plurality of target images, wherein the trapping position is the position where the cold atomic group is trapped by the magneto-optical trap; and 4, calculating coordinate jitter errors of the trapping positions in the multiple target images, and calculating a first adjustment coefficient of the magneto-optical trap according to the coordinate jitter errors. Through the technical scheme in this application, be favorable to improving the accuracy of confirming cold atom group imprisoned position, improve cold atom interferometer's interference effect and parameter adjustment's accuracy.
The steps in the present application may be sequentially adjusted, combined, and subtracted according to actual requirements.
The units in the device can be merged, divided and deleted according to actual requirements.
Although the present application has been disclosed in detail with reference to the accompanying drawings, it is to be understood that such description is merely illustrative and is not intended to limit the application of the present application. The scope of the present application is defined by the appended claims and may include various modifications, adaptations, and equivalents of the invention without departing from the scope and spirit of the application.
Claims (4)
1. A method for improving the polishing precision of atom group pairs is characterized by being suitable for a cold atom interferometer, wherein the cold atom interferometer comprises a magnetic trap and a photosensitive camera, the shooting area of the photosensitive camera is right opposite to the magnetic trap, and the method comprises the following steps:
step 1, when cooling light of the magneto-optical trap is turned on and a gradient magnetic field is turned off, acquiring a background image of the magneto-optical trap by using the photosensitive camera;
step 2, acquiring a plurality of target images of the magneto-optical trap after the cooling light and the gradient magnetic field are opened and the cold radicals are trapped by the photosensitive camera successively;
step 3, calculating the trapping position of the cold atomic group for each target image by adopting a differential algorithm according to the background image and the plurality of target images, wherein the trapping position is the position where the magneto-optical trap traps the cold atomic group;
step 4, calculating coordinate jitter errors of the imprisoned positions in the plurality of target images, and calculating a first adjustment coefficient of the magneto-optical trap according to the coordinate jitter errors, wherein the first adjustment coefficient comprises a first optical path coefficient and a first magnetic field coefficient, and a calculation formula of the first adjustment coefficient f (·) is as follows:
σ pos (u)＝f(P(u)，A(u)，F(u)，C(u)，G(u))，u＝1，2，3…U
in the formula, σ pos (u) is the coordinate dithering error corresponding to the u-th target image, P (u) is the light intensity of the cooling light corresponding to the u-th target image, A (u) is the corresponding casting angle of the cold radicals, F (u) is the corresponding cooling light frequency, C (u) is the corresponding magnetic field current intensity, and G (u) is the corresponding magnetic field gradient.
2. The method for improving the precision of the polishing of the atomic group pair as claimed in claim 1, wherein the step 3 specifically comprises:
step 31, sequentially selecting one target image according to the background image and the sequence of the target images, calculating pixel revision values of pixel points in the target images by adopting the difference algorithm, and generating revised images, wherein the calculation formula of the pixel revision values is as follows:
in the formula, P t Revising a value, P, for the pixel 0 Is the pixel value, P, of a pixel point in the background image p For the pixel values of the pixel points in the pth target image, p =1, 2., N;
step 32, sequentially selecting pixel points with the maximum pixel values in the revised image, recording the pixel points as central points, and determining an image area ROI of the revised image by taking the selected central points as the centers, wherein the image area comprises all light spots;
and step 33, calculating the light spot mass center of the image region ROI according to the pixel value in the image region ROI, and recording the light spot mass center as the imprisoned position of the target image.
3. The method for improving the polishing precision of the atomic group pair as recited in claim 2, wherein the step 33 further comprises:
step 331, calculating the centroid (x) of the light spot 0 ，y 0 ) Constructing a transverse bisector and a longitudinal bisector of the image region ROI at equal intervals for a coordinate origin, wherein the number K of the transverse bisector and the longitudinal bisector is an odd number, and the (K-1)/2 th transverse bisector and the (K-1)/2 th longitudinal bisector pass through the centroid of the light spot;
step 332, calculating the transverse center coordinate on any one of the transverse bisectors according to the pixel value in the image region ROI by using a Gaussian fitting model, and
calculating the longitudinal center coordinate on any one longitudinal bisector, wherein the calculation formula of the gaussian fitting model is as follows:
wherein, B is the pixel value, w is the coordinate value of the transverse bisector or the longitudinal bisector, a is the amplitude, B is the transverse center coordinate or the longitudinal center coordinate, and c is the fitting radius;
step 333, generating a light spot center according to the average value of the transverse center coordinates and the average value of the longitudinal center coordinates, and recording the light spot center as the imprisoned position.
4. The method for improving the polishing precision of a radical pair as recited in claim 1, further comprising:
step 5, after the cold atomic group is trapped, acquiring a casting image of the cold atomic group one by one, calculating a position coordinate of the cold atomic group in a casting process, and fitting and generating a casting track of the cold atomic group in the casting process according to the position coordinate;
step 6, calculating the track coincidence degree of the casting track, and calculating a second adjustment coefficient of the magneto-optical trap according to the track coincidence degree, wherein the second adjustment coefficient comprises a second light path coefficient and a second magnetic field coefficient, and the calculation formula of the second adjustment coefficient g (-) is as follows:
g(Δ(u′)，T1(u′)，T2(u′))＝σ diff (u′)，u′＝1，2，3…U′
in the formula, σ diff (u ') is the track coincidence degree of the u ' th cast track, delta (u ') is the corresponding cooling light frequency detuning amount, T1 (u ') is the corresponding cooling light illumination time, and T2 (u ') is the corresponding magnetic field action time.
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| CN112729298B (en) * | 2020-12-24 | 2023-01-10 | 华中光电技术研究所（中国船舶重工集团公司第七一七研究所） | Multi-gyroscope atomic group position synchronous control method |
| CN116738590A (en) * | 2023-04-03 | 2023-09-12 | 中国计量科学研究院 | Optimization method and device for cold atom magneto-optical trap system |
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