从理论上分析了偏振光束与双折射晶体粒子的相互作用过程,讨论了由于光束自旋角动量向晶体粒子的传递所导致的光致旋转效应的原理,通过MATLAB仿真分析,研究了粒子的旋转频率随激光功率的变化关系,得出粒子转动频率与激光功率成正比。利用光镊装置,采用波长为632.8 nm的He-Ne激光器,在不同的激光功率下实现对不同半径双折射粒子的旋转,测量了光致旋转的转动频率,最高转速可达5 r/s,并得出了不同粒子的旋转频率随激光功率的变化关系,实验结果和理论分析基本一致。分析了产生误差的原因,其中载波片底面的摩擦影响最大。

The principle of optical rotation due to the transfer of spin angular momentum from light to particles was discussed by analyzing the interaction between the beam of light and birefringent crystal particles. Through MATLAB simulation, the dependence of the rotation frequency of the trapped particle on the laser power was analyzed, it was obtained that the rotation frequency was proportional to the laser power. The birefringent different particles were rotated by the optical tweezers, the wavelength of He-Ne laser was 632.8 nm, at the same time the rotation frequency was measured, and the maximum speed could reach 5 r/s. The dependence of the rotation frequency of the trapped particle on the laser-power was experimentally studied for several birefringent particles with different sizes in the optical tweezers. When experimental results were compared with theoretical results, experimental results and theoretical analysis were agreeing very well, and the reasons for the error were analyzed, which the bottom friction affected the most.