Frequency-adjustable stable rotating device in vacuum optical tweezers system and use method

Abstract

The invention discloses a frequency-adjustable stable rotating device in a vacuum optical tweezers system and a use method. The device comprises a vacuum cavity, micro-nano particles, a laser source, an objective lens and a polarization control device, wherein the objective lens and the micro-nano particles are placed in the vacuum cavity, the laser source, the polarization control device, the objective lens and the micro-nano particles are sequentially arranged in a light direction, the polarization control device comprises a first half-wave plate, a polarizing beam splitter, a second half-wave plate, an electro-optical modulator and a quarter-wave plate, and the first half-wave plate, the polarizing beam splitter, the second half-wave plate, the electro-optical modulator and the quarter-wave plate are sequentially arranged in the light direction. According to the invention, the function of controlling the micro-nano particles to stably rotate at a set frequency in a vacuum optical tweezers system is realized by utilizing the modulation effect of the electro-optical modulator on light beam polarization and combining the interaction characteristic of linearly polarized light and the micro-nano particles with anisotropic polarizability.

Description

technical field [0001] The invention relates to a device for realizing the stable rotation of micro-nano particles in a vacuum, belonging to the technical field of precision measurement, in particular to a frequency-adjustable stable rotation device in a vacuum optical tweezers system and a use method thereof. Background technique [0002] In the 1970s, American physicist Ashkin and others took advantage of the properties that objects would be subjected to radiation force and gradient force in the light field, and invented the optical tweezers technology to capture tiny particles. This technology is widely used in research fields such as fluid mechanics and thermodynamics. Later, the vacuum optical tweezers technology was developed, which uses light to trap particles in a vacuum. This method can be well decoupled from the environment, thereby obtaining very high measurement accuracy. For example, vacuum optical tweezers can be used to measure non-Newtonian gravity, Casimir ...

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Problems solved by technology

Moreover, the circularly polarized light method is used to control the rotation speed through the balance of optical field drive and gas retardation, so that the rotation speed is easily disturbed by changes in light intensity and air flow, so the line width of the rotation frequency is large, that is, it is unstable.

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