Absolute gravitational acceleration measuring system and method based on light floating effect

Abstract

The invention provides an absolute gravitational acceleration measuring system and method based on a light floating effect. According to the system, a vacuum chamber and a hollow-core optical fiber light trap structure are adopted to provide a high-vacuum environment and a large moving stroke for light capturing working particles, an acousto-optic modulator is used for conducting high-frequency modulation on laser power at the two ends of a hollow-core optical fiber, and a control system and a control algorithm are used for achieving movement cooling, stable suspension and free falling of the micron-sized working particles. And after the working particles are stably suspended, closing the laser to enable the working particles to freely fall along the Z axis in a pure gravity field, precisely measuring and recording the falling height and the falling time of the working particles, and calculating an absolute gravitational acceleration value based on a working particle kinetic equation under the action of gravity. And after the measurement is completed, reactivating the laser to capture the falling working particles and resetting to the initial height, thereby realizing the repeatable absolute gravity measurement of the single working particle.

Description

Technical Field

[0001] The present invention belongs to the field of absolute gravity measurement and optical measurement, and in particular relates to an absolute gravity acceleration measurement system and method based on optical buoyancy effect. Background Art

[0002] As a key means of geophysical exploration, resource exploration and basic physics research, the accuracy and reliability of absolute gravity measurement technology directly affect the scientific value of observation results. In addition, absolute gravity measurement is also an important supplementary data in the process of inertial measurement and integrated navigation calculation. The accuracy of absolute gravity acceleration measurement determines the stability of inertial measurement and integrated navigation calculation to a certain extent. The free-fall absolute gravity method is an important part of absolute gravity measurement technology. It inverts the gravity acceleration value by precisely measuring the free-fall trajectory of the test mass block in the vacuum chamber. However, the movement of the mass block depends on the mechanical release device, which is easy to introduce lateral velocity errors at the moment of release; the macroscopic mass block is easily coupled by ground vibration noise, requiring a complex vibration isolation system, resulting in a relatively large system volume and inability to be deployed mobile. This scheme uses mesoscopic micron-sized working particles as sensitive media and uses lasers as a tool for contactless suspension and release, which can better solve the above problems.

[0003] Gravimeters based on optical tweezers technology have also made some progress. For example, patent US20180321024A1 discloses a method of suspending micron-sized particles through optical tweezers and measuring their displacement response under external force; Chinese patent application CN10981465A discloses a photo-cooled miniaturized high-precision optical gravimeter, which works based on the principle of free-falling particles and infers gravity through the relationship between falling time and falling position. However, related research has the following problems: the traditional optical tweezers system has a short working distance, and the insufficient falling stroke of the working particles leads to limited measurement time resolution and increased gravity measurement error; the open optical path design is easily affected by air turbulence and thermal convection, and gas resistance introduces systematic deviations, and the participating gas may cause radial displacement of the working particles, deviating from the detection center, and unable to measure valid data; continuous measurement requires the addition of new working particles, resulting in measurement inconsistencies caused by vacuum system contamination and differences in working particle characteristics. Summary of the invention

[0004] In order to solve the problems in the prior art that the working particle travel is too short, it is easily affected by residual gas in the vacuum and it is difficult to repeat the measurement, the present invention provides an absolute gravity acceleration measurement system and method based on the optical levitation effect, which overcomes the above difficulties while maintaining the high precision and miniaturization of the optical tweezers system.

[0005] The present invention uses hollow-core fiber optical floating and working particles to freely fall to measure absolute gravitational acceleration, and uses AOM and self-developed intelligent control algorithms to achieve stable capture, free fall and resetting of working particles. Hollow-core optical fiber provides a more stable high-vacuum environment and a large axial range of freedom for working particles. The free-fall absolute gravitational acceleration measurement method isolates the influence of other signals such as light, heat, and electromagnetics on the system, making the gravity measurement more accurate. The optical power modulation technology based on AOM and the self-developed intelligent control algorithm provide technical support for the free manipulation of working particles, and provide the possibility for further improvement of repeated measurement of gravitational acceleration and accuracy of single working particles. The present invention can be applied to related research on optical floating gravimeters, and is expected to form an independent instrument for use in situations requiring high-precision gravity measurement, such as aerospace, inertial measurement, navigation and guidance, etc.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme:

[0007] An absolute gravity acceleration measurement system based on optical buoyancy effect, comprising:

[0008] The light trap module uses the dual beams in the hollow-core optical fiber to form a three-dimensional light trap, which captures and suspends micron-sized working particles. The light trap height is controlled by adjusting the laser power, so that the working particles can move in a controlled manner under the balance of gravity and light force.

[0009] The imaging detection module uses a focusing aspheric lens group and a CMOS camera to calibrate the position and track the motion trajectory of the captured working particles in the direction of gravity, and combines the digital image correlation algorithm to calibrate the axial displacement of the working particles;

[0010] The photoelectric detection module uses the interference displacement detection method and the differential photoelectric detector to capture the position of the working particles in the direction of gravity, converts the position signal of the working particles into a voltage signal, and cooperates with the imaging detection module to perform voltage-position calibration and measure the axial displacement of the working particles;

[0011] A vacuum chamber, used to provide a vacuum environment for working particles;

[0012] The signal acquisition and control system is used to collect the photoelectric signals generated by the photoelectric detection module and the image signals generated by the imaging detection module, and analyze and process each data to complete the initial calibration of the system, dynamically adjust the light trap laser power, measure the time and height of the free fall process of the working particles, and calculate the absolute gravitational acceleration.

[0013] A method for measuring absolute gravitational acceleration based on optical buoyancy effect comprises the following steps:

[0014] Step S1: synchronously input a 532nm low-power detection laser and a 1064nm high-power single-mode laser as the detection laser and the capture laser, the capture laser is input into the first plano-convex lens, the second plano-convex lens, and the flat-field objective lens through an acousto-optic modulator, and enters the hollow-core optical fiber, the detection laser is focused onto the hollow-core optical fiber through the upper focusing aspheric lens group and the lower focusing aspheric lens group, respectively, and a double-beam light trap is constructed in the hollow-core optical fiber; given the initial parameters of the signal acquisition and control system, a single working particle is stably captured under a standard atmospheric pressure environment, and the laser power is controlled so that the working particle is accurately positioned at the focusing center of the upper focusing aspheric lens group, and the height h1 of the center of mass of the working particle relative to the reference plane is measured and recorded at this time;

[0015] Step S2: activating the active feedback cooling system to achieve cooling feedback control and thermal motion of the working particles;

[0016] Step S3: When the working environment air pressure and the Brownian motion of the working particles are stable, the standard time t1 is recorded, and the capture laser is turned off to allow the working particles to fall freely under the action of gravity;

[0017] Step S4: when the working particle passes through the focusing center area of ​​the lower light-collecting aspheric lens group, the height h2 of the mass center of the working particle of the lower light-collecting aspheric lens group relative to the reference plane and the termination time t2 are synchronously recorded;

[0018] Step S5: After recording is completed, the laser captures the falling working particles, and the center of mass of the working particles is reset to the initial height h1 under the action of the acousto-optic modulator and the intelligent algorithm, and the absolute gravity value is calculated at the same time. Under high vacuum conditions, the absolute gravity can be calculated. ;

[0019] Step S6: After the working particles are reset and recooled, steps S3-S5 are repeated again to repeatedly measure the absolute gravity value N times; the N measurement data are statistically analyzed by the least squares method, and finally the standard gravity acceleration and its uncertainty estimation are output.

[0020] Beneficial effects:

[0021] In order to address the problems of the influence of residual gas in vacuum and the short free movement range of working particles in traditional optical tweezers, the present invention uses a hollow-core fiber structure and utilizes an objective lens to couple the laser into the hollow-core fiber. The laser propagates in parallel as a single-mode Gaussian beam in the hollow-core fiber. Through the hollow-core fiber waveguide confinement and high vacuum environment, a stable working environment is provided for the working particles to avoid the influence of residual gas on the measurement. The self-developed control system and intelligent algorithm can achieve precise control of the working particles, further reducing Brownian motion noise and gravity measurement sensitivity; the innovatively designed single working particle repeated measurement mechanism avoids the interaction error of the traditional multi-working particle system, and combined with the reset function of the intelligent control system, the time of a single measurement cycle can be greatly shortened. Multi-sensor acquisition and fusion measurement algorithms are used to maintain displacement detection accuracy and further improve gravity measurement sensitivity.

[0022] In summary, the present invention creatively applies the optical levitation effect to the free-fall absolute gravity acceleration measurement, and constructs a new generation of miniaturized high-precision absolute gravity measurement system. The use of hollow-core optical fiber to construct the optical trap system solves the problems of the influence of air residual gas and the short free movement of working particles in traditional optical tweezers; the introduction of the capture-cooling-falling-resetting process mechanism of a single working particle avoids the interaction error of the traditional multi-working particle system and the pollution of the vacuum environment. The theoretical method and experiment of this scheme are credible, with important technical value and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of an absolute gravity acceleration measurement system based on optical levitation effect of the present invention;

[0024] Figure 2 The figure is a flow chart of the absolute gravitational acceleration measurement method based on the optical levitation effect of the present invention.

[0025] Among them, the figure markings are: 1-acoustic-optic modulator; 2-first plano-convex lens; 3-second plano-convex lens; 4-flat field objective lens; 51-upper focusing aspheric lens group; 52-lower focusing aspheric lens group; 6-hollow core optical fiber; 7-working particles; 81-upper electric shutter; 82-lower electric shutter; 91-upper beam splitter prism; 92-lower beam splitter prism; 10-imaging reflector; 11-imaging focusing lens; 12-CMOS camera; 131-upper D-type mirror; 132-lower D-type mirror; 141-upper plane reflector; 142-lower plane reflector; 151-upper focusing lens group; 152-lower focusing lens group; 161-upper differential photodetector; 162-lower differential photodetector; 17-vacuum cavity; 18-signal acquisition and control unit. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other. To achieve the above-mentioned purpose, the present invention adopts the following technical scheme.

[0027] The present invention provides an absolute gravity acceleration measurement system based on optical levitation effect, such as Figure 1 As shown, including:

[0028] The light trap module uses the dual light beams in the hollow-core optical fiber 6 to form a three-dimensional light trap, capture and suspend the micron-sized working particles 7, and adjust the laser power and light trap height to make the working particles 7 move in a controlled manner under the balance of gravity and light force;

[0029] An imaging detection module is used to use an aspherical lens group and a CMOS camera 12 to calibrate the position and track the motion trajectory of the captured working particle 7 in the gravity direction (axial direction), and to calibrate the axial displacement of the working particle 7 in combination with a digital image correlation algorithm;

[0030] The photoelectric detection module uses the interference displacement detection method and the differential photoelectric detector to accurately measure the position of the working particle 7 in the gravity direction (axial direction), and converts the position signal of the working particle 7 into a voltage signal. It cooperates with the imaging detection module to perform voltage-position calibration and high-precision measurement of the axial displacement of the working particle 7;

[0031] The vacuum chamber is used to provide a high vacuum environment and reduce air convection and Brownian motion noise. The vacuum chamber is installed on an air-floating vibration isolation platform to suppress the interference of mechanical vibration on the stability of the light trap;

[0032] The signal acquisition and control system is used to collect the photoelectric signal generated by the photoelectric detection module and the image signal generated by the imaging detection module, and analyze and process each data to complete the initial calibration of the system. The light trap laser power is dynamically adjusted based on the control algorithm to achieve cooling feedback control of the working particle 7 and closed-loop control of the equilibrium position. The time and height of the free fall process of the working particle 7 are measured to calculate the absolute gravitational acceleration.

[0033] The light trap module includes an acousto-optic modulator 1, a first plano-convex lens 2, a second plano-convex lens 3, a flat-field objective lens 4 and a hollow-core optical fiber 6; wherein, the acousto-optic modulator 1, the first plano-convex lens 2, the second plano-convex lens 3 and the flat-field objective lens 4 are two sets, which are symmetrically arranged on the upper and lower sides of the hollow-core optical fiber 6. The acousto-optic modulator 1, the first plano-convex lens 2, the second plano-convex lens 3, the flat-field objective lens 4 and the hollow-core optical fiber 6 are collimated and installed along the gravity direction, and a high-performance single-mode high-power 1064nm laser generates a high-performance Gaussian beam, which is then expanded by a beam expansion lens group composed of a first plano-convex lens 2 and a second plano-convex lens 3 after power modulation by the acousto-optic modulator 1, so that the beam waist covers the rear pupil of the 100-fold 0.8NA flat-field objective lens 4, and is focused into the hollow-core optical fiber 6 to form a stable light trap, which is used to capture and suspend micron-sized working particles 7, and the cooling feedback control and balance height control of the working particles 7 are performed by adjusting the laser power.

[0034] The imaging detection module includes an upper focusing aspheric lens group 51, a lower focusing aspheric lens group 52, an upper electric shutter 81, a lower electric shutter 82, an upper dichroic prism 91, a lower dichroic prism 92, an imaging reflector 10, an imaging focusing lens 11, and a CMOS camera 12; wherein the upper aspheric focusing lens group 51 and the lower aspheric focusing lens group 52 provide a focusing light source for image acquisition and detect the position of the working particles 7; the upper electric shutter 81 and the lower electric shutter 82 are used to screen the detection position of the working particles 7, the upper dichroic prism 91 and the lower dichroic prism 92 are used to separate the optical path of the imaging detection module and the optical path of the photoelectric detection module, and the imaging reflector 10 and the imaging focusing lens 11 are used to change the direction of the optical path and focus it into the CMOS camera 12.

[0035] The photoelectric detection module includes an upper electric shutter 81, a lower electric shutter 82, an upper beam splitter prism 91, a lower beam splitter prism 92, an upper D-type mirror 131, a lower D-type mirror 132, an upper plane reflector 141, a lower plane reflector 142, an upper condensing lens group 151, a lower condensing lens group 152, an upper differential photodetector 161, and a lower differential photodetector 162; wherein the upper electric shutter 81 and the lower electric shutter 82 are used to screen the position of the working particles, and the upper beam splitter prism 91 and the lower beam splitter prism 92 are used to separate the imaging detection Module optical path and photoelectric detection module optical path; the upper D-type mirror 131 and the lower D-type mirror 132 are used to divide the detection light beam into two parts, an upper part and an lower part, along the center of light beam propagation. One light beam propagates along the original direction, and the other light beam is sent to the upper plane reflector 141 and the lower plane reflector 142 for realignment; the upper focusing lens group 151 and the lower focusing lens group 152 are used to refocus the detection light beam to the photosensitive plane of the upper differential photodetector 161 and the lower differential photodetector 162, and convert the position signal of the working particle 7 into a voltage signal.

[0036] The upper focusing aspheric lens group 51, the lower focusing aspheric lens group 52, the hollow core optical fiber 6, the working particles 7 and the flat field objective lens 4 are placed in the vacuum chamber to provide a high vacuum environment and isolate the external air disturbance;

[0037] The signal acquisition and control system is also used to control the electric shutter to screen the working particle detection position of the CMOS camera and the photoelectric detection module, and control the acousto-optic modulator 1 to change the laser power to achieve cooling feedback, free fall and rapid reset of the micron-sized working particles 7.

[0038] Furthermore, the hollow core fiber 6 adopts a double-cladding microstructure design, and uses a flat field objective lens 4 to couple the laser into the hollow core fiber 6, and the laser propagates in parallel as a single-mode Gaussian beam in the hollow core fiber 6. The ratio of the core diameter to the particle size of the working particle 7 is controlled within the range of 1.5-2.0, and the axial motion cooling and long-stroke falling of the working particle 7 are achieved through the waveguide confinement effect, while further isolating the influence of residual gas in the vacuum environment, thereby improving the sensitivity of gravity detection.

[0039] Furthermore, the imaging detection module and the photoelectric detection module are used to collaboratively acquire displacement information, thereby realizing multi-sensor data fusion and improving the calibration and displacement detection accuracy of the working particles 7 .

[0040] Furthermore, an electric shutter and a beam splitter prism are used to dynamically control the optical path, and the on-off is intelligently switched according to the falling stage and position of the working particle 7, so that the imaging detection module and the photoelectric detection module always follow the axial movement of the working particle to avoid signal redundancy and stray light interference.

[0041] The present invention also provides a method for measuring absolute gravitational acceleration based on optical levitation effect, comprising the following steps:

[0042] Step S1: Synchronously input 532nm low-power detection laser and 1064nm high-power single-mode laser as detection laser and capture laser. The capture laser is input into the first plano-convex lens 2, the second plano-convex lens 3, and the flat-field objective lens 4 through the acousto-optic modulator 1, and enters the hollow-core optical fiber 6. The detection laser is focused on the hollow-core optical fiber 6 through the upper focusing aspheric lens group 51 and the lower focusing aspheric lens group 52, and a double-beam light trap is constructed in the hollow-core optical fiber 6. Given the initial parameters of the signal acquisition and control system, the stable capture of a single working particle 7 is achieved under a standard atmospheric pressure environment, and the laser power is manipulated to accurately position the working particle 7 at the focusing center of the upper focusing aspheric lens group 51. Measure and record the height h1 of the center of mass of the working particle 7 relative to the reference plane at this time.

[0043] Step S2: Activate the active feedback cooling system to achieve cooling feedback control and thermal motion stabilization of the working particles 7. After sealing the vacuum chamber, turn on the mechanical pump, molecular pump and ion pump in sequence, and reduce the air pressure while maintaining stable capture of the optical trap until the system reaches 10 -6 Stable high vacuum environment of Pa level.

[0044] Step S3: When the working environment air pressure and the Brownian motion of the working particle 7 are stable, the standard time t1 is recorded, and the capture laser is turned off to allow the working particle 7 to fall freely under the action of gravity.

[0045] Step S4: When the working particle 7 passes through the focusing center area of ​​the lower focusing aspheric lens group 52, the height h2 of the center of mass of the working particle of the lower focusing aspheric lens group 52 relative to the reference plane and the termination time t2 are synchronously recorded.

[0046] Step S5: After recording is completed, the laser captures the falling working particle 7, and the center of mass of the working particle 7 is reset to the initial height h1 under the action of the acousto-optic modulator 1 and the intelligent algorithm. At the same time, the absolute gravity value is calculated. Under high vacuum conditions, the absolute gravity can be calculated. ;

[0047] Step S6: After the working particles 7 are reset and recooled, steps S3-S5 are repeated to measure the absolute gravity value N times. The N measurement data are statistically analyzed by the least square method, and the standard gravity acceleration and its uncertainty estimation are finally output.

[0048] Furthermore, in the step S1 , the composite light field of the capture laser and the detection laser is used to achieve stable capture, cooling feedback control and free fall of the working particles 7 in the hollow-core optical fiber 6 , further isolating the influence of residual gas in the vacuum chamber 17 .

[0049] Furthermore, in the steps S3-S5, the hollow core optical fiber realizes long-stroke displacement control of a single working particle 7 along the Z axis under the action of optical power modulation, including the falling and resetting process of the working particle, and can realize repeatable absolute gravity measurement using a single working particle.

[0050] Furthermore, in the steps S3-S5, the signal detection and control system can control the axial displacement of the working particles by adjusting the optical power in real time; can automatically select the detection optical path, and adjust the optical path structure in real time through the electric shutter to avoid signal redundancy and interference; can autonomously stop the falling and reset of the working particles, and ensure that the working particles 7 always move in the large travel environment constructed by the hollow-core optical fiber 6.

Claims

1. An absolute gravity acceleration measurement system based on optical levitation effect, characterized in that: include: The light trap module uses the dual beams in the hollow-core optical fiber to form a three-dimensional light trap, which captures and suspends micron-sized working particles. The light trap height is controlled by adjusting the laser power, so that the working particles can move in a controlled manner under the balance of gravity and light force. The imaging detection module uses a focusing aspheric lens group and a CMOS camera to calibrate the position and track the motion trajectory of the captured working particles in the direction of gravity, and combines the digital image correlation algorithm to calibrate the axial displacement of the working particles; The photoelectric detection module uses the interference displacement detection method and the differential photoelectric detector to capture the position of the working particles in the direction of gravity, converts the position signal of the working particles into a voltage signal, and cooperates with the imaging detection module to perform voltage-position calibration and measure the axial displacement of the working particles; A vacuum chamber, used to provide a vacuum environment for working particles; The signal acquisition and control system is used to collect the photoelectric signals generated by the photoelectric detection module and the image signals generated by the imaging detection module, and analyze and process each data to complete the initial calibration of the system, dynamically adjust the light trap laser power, measure the time and height of the free fall process of the working particles, and calculate the absolute gravitational acceleration.

2. The absolute gravity acceleration measurement system based on optical levitation effect according to claim 1, characterized in that: The light trap module includes an acousto-optic modulator, a first plano-convex lens, a second plano-convex lens, a flat-field objective lens and a hollow-core optical fiber; wherein the acousto-optic modulator, the first plano-convex lens, the second plano-convex lens and the flat-field objective lens are two sets, which are symmetrically arranged on the upper and lower sides of the hollow-core optical fiber, and the acousto-optic modulator, the first plano-convex lens, the second plano-convex lens, the flat-field objective lens and the hollow-core optical fiber are collimated and installed along the direction of gravity.

3. The absolute gravity acceleration measurement system based on optical levitation effect according to claim 1, characterized in that: A single-mode high-power 1064nm laser generates a high-performance Gaussian beam, which is modulated by the acousto-optic modulator and then expanded by a beam expander consisting of a first plano-convex lens and a second plano-convex lens, so that the beam waist covers the rear pupil of the flat-field objective lens and is focused into a hollow-core optical fiber to form a stable light trap, which is used to capture and suspend micron-sized working particles. The cooling feedback control and balance height control of the working particles are performed by adjusting the laser power.

4. The absolute gravity acceleration measurement system based on optical levitation effect according to claim 1, characterized in that: The imaging detection module includes an upper focusing aspheric lens group, a lower focusing aspheric lens group, an upper electric shutter, a lower electric shutter, an upper splitter prism, a lower splitter prism, an imaging reflector, an imaging focusing lens, and a CMOS camera; The upper aspheric condensing lens group and the lower aspheric condensing lens group provide focused light sources for image acquisition and also detect the position of the working particles; the upper electric shutter and the lower electric shutter are used to screen the detection position of the working particles, the upper dichroic prism and the lower dichroic prism are used to separate the optical path of the imaging detection module and the optical path of the photoelectric detection module, and the imaging reflector and the imaging condensing lens are used to change the direction of the light path and focus it into the CMOS camera.

5. The absolute gravity acceleration measurement system based on optical levitation effect according to claim 1, characterized in that: The photoelectric detection module also includes an upper electric shutter, a lower electric shutter, an upper splitter prism, and a lower splitter prism. In addition, it also includes an upper D-type mirror, a lower D-type mirror, an upper plane reflector, a lower plane reflector, an upper focusing lens group, a lower focusing lens group, an upper differential photodetector, and a lower differential photodetector; wherein, the upper D-type mirror and the lower D-type mirror are used to divide the detection beam into two parts, an upper part and an lower part, along the center of beam propagation, one beam of light propagates along the original direction, and the other beam of light is respectively sent to the upper plane reflector and the lower plane reflector for realignment; the upper focusing lens group and the lower focusing lens group are used to refocus the detection beam onto the photosensitive planes of the upper differential photodetector and the lower differential photodetector, and convert the position signal of the working particle into a voltage signal.

6. The absolute gravity acceleration measurement system based on optical levitation effect according to claim 1, characterized in that: The upper light-gathering aspheric lens group, the lower light-gathering aspheric lens group, the hollow-core optical fiber, the working particles and the flat-field objective lens are placed in a vacuum chamber.

7. The absolute gravity acceleration measurement system based on optical levitation effect according to claim 1, characterized in that: The hollow core fiber adopts a double-cladding microstructure, and the laser propagates in parallel in the hollow core fiber as a single-mode Gaussian beam.

8. The absolute gravity acceleration measurement system based on optical levitation effect according to claim 1, characterized in that: The ratio of the core diameter of the hollow core optical fiber to the particle size of the working microparticles is controlled within the range of 1.5-2.

0.

9. The absolute gravity acceleration measurement system based on optical levitation effect according to claim 1, characterized in that: The signal acquisition and control system is also used to control the electric shutter to screen the working particle detection position of the CMOS camera and the photoelectric detection module.

10. A method for measuring absolute gravitational acceleration based on optical levitation effect, characterized in that: The following steps are involved: Step S1: synchronously input a 532nm low-power detection laser and a 1064nm high-power single-mode laser as the detection laser and the capture laser, the capture laser is input into the first plano-convex lens, the second plano-convex lens, and the flat-field objective lens through an acousto-optic modulator, and enters the hollow-core optical fiber, the detection laser is focused onto the hollow-core optical fiber through the upper focusing aspheric lens group and the lower focusing aspheric lens group, respectively, and a double-beam light trap is constructed in the hollow-core optical fiber; given the initial parameters of the signal acquisition and control system, a single working particle is stably captured under a standard atmospheric pressure environment, and the laser power is controlled so that the working particle is accurately positioned at the focusing center of the upper focusing aspheric lens group, and the height h1 of the center of mass of the working particle relative to the reference plane is measured and recorded at this time; Step S2: activating the active feedback cooling system to achieve cooling feedback control and thermal motion of the working particles; Step S3: When the working environment air pressure and the Brownian motion of the working particles are stable, the standard time t1 is recorded, and the capture laser is turned off to allow the working particles to fall freely under the action of gravity; Step S4: when the working particle passes through the focusing center area of ​​the lower light-collecting aspheric lens group, the height h2 of the mass center of the working particle of the lower light-collecting aspheric lens group relative to the reference plane and the termination time t2 are synchronously recorded; Step S5: After recording is completed, the laser captures the falling working particles, and the center of mass of the working particles is reset to the initial height h1 under the action of the acousto-optic modulator and the intelligent algorithm, and the absolute gravity value is calculated at the same time. Under high vacuum conditions, the absolute gravity can be calculated. ; Step S6: After the working particles are reset and recooled, steps S3-S5 are repeated again to repeatedly measure the absolute gravity value N times; the N measurement data are statistically analyzed by the least squares method, and finally the standard gravity acceleration and its uncertainty estimation are output.

11. The absolute gravity acceleration measurement method based on optical levitation effect according to claim 10, characterized in that: After sealing the vacuum chamber, turn on the mechanical pump, molecular pump and ion pump in sequence, and reduce the gas pressure while maintaining stable capture of the light trap until the system reaches a vacuum environment.

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