Gravity measurement device and method based on optical trap

Abstract

The invention discloses a gravity measurement device and method based on an optical trap. The device comprises an optical trap capturing module, a vacuum module, a feedback module and a position detection module, wherein the vacuum module is used for enabling microspheres to be in a high-vacuum environment during gravity testing; the optical trap capturing module is used for capturing the microspheres in the vacuum environment and cooling the microspheres to perform centroid motion; the laser intensity is adjusted to be zero through an acoustic optical modulator (AOM) so as to close the optical trap; at the moment, the microspheres fall freely under the action of gravity, after a short time, the AOM is controlled to open the optical trap again, the microspheres are captured again, the freefalling process of the microspheres is measured through the position detection module, and absolute gravity measurement can be carried out according to the falling process of the microspheres. By repeating the process, continuous measurement of absolute gravity can be realized. According to the invention, free falling of the suspended microspheres is realized by utilizing the optical trap under ahigh vacuum condition so that the absolute gravity of the environment is calibrated, and the device has the advantages of short test time, small size and capability of continuously measuring the absolute gravity.

Description

technical field [0001] The invention relates to the technical field of optical trap-based measurement, and more specifically, to a gravimetric measurement device and method based on an optical trap. Background technique [0002] According to quantum theory, a light beam is a group of photons that move at the speed of light and have both mass and momentum. When the photons are incident on the surface of the medium, refraction and reflection will occur, and the speed and direction of the photons will change, resulting in a change in their momentum vector. The conservation law can be deduced that when the beam irradiates the particle, the momentum change of the photon is equal to the momentum change of the particle, so the beam has a mechanical effect on the particle, which is called the optical radiation pressure, and the optical radiation pressure includes the scattering along the beam propagation direction Under the action of these two forces, the light beam can capture the ...

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Problems solved by technology

[0003] The existing gravity measurement method mainly uses the method of mechanically releasing the mass block, and realizes the measurement of its absolute gravity through the free fall movement of the mechanical block, but this measurement method has many shortcomings such as complex reset, large volume, and many error factors.

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