Experimental and Theoretical Studies of Optically Driven Rotation of Calcium Carbonate Particles
碳酸钙微粒光致旋转的实验和理论研究

The mechanisms of optically driven rotation of particles by using orbital angular momentum and spin angular momentum of light as well as by using specially shaped particles are analyzed in this paper.An optical tweezers is set up in the experiment.It can not only trap and move micro-sized particles but also rotate birefringent calcium carbonate particles by using the spin angular momentum transfer of the circular polarized light to the particles.It is found that the optical rotation depends not only on the polarization of the incident light but also on the shape of the particle.Various rotation phenomena observed in our experiment are analysed and explained.The maximal rotation speed of the calcium carbonate particle can reach 12 rps.The rotation speed is proportional to the light intensity.