Abstract

A laser beam can be used to rotate objects with artificial non-symmetrical structures(1). In this paper we present numerical results for optical torque exerted on the star- and cross-type rotators. We assumed the objects are subjected to a strongly focused fundamental TEMoo Gaussian laser beam. The optical force resulting from reflection and refraction at the surface of the objects was calculated using the ray-optics model. We studied star- and cross-type rotators (polyimide, n2=1.525) suspended in liquid (ethanol, n1=1.363). From the experimental and the numerical results, we quantified the damping factor and the static frictional torque of the rotators.

© 1998 IEEE