Optical tweezers have been used as a powerful, non-invasive tool in investigations covering many areas, including biology, for over a decade . Rotation of trapped particles in optical tweezers offers a new degree of control for micro-objects and has significant applications in optical micro machines and biotechnology. Previous schemes to induce rotation of trapped particles include the transfer (by absorption) of orbital angular momentum from an optical vortex beam to the trapped particle [2,3]. An alternative scheme uses a birefringent particle and transfers angular momentum by the change in polarisation state of the trapping light upon passage through the trapped particle .
© 2001 Optical Society of AmericaPDF Article