Abstract

In 1970 it was discovered for the first time that the forces of radiation pressure from lasers can accelerate and trap neutral particles [1]. Since then, based on this effect -“the optical tweezer effect”- researchers have been able to manipulate and trap particles as diverse as atoms, molecules, dielectric spheres with sizes ranging from nanometers to microns, even biological systems such as bateria, viruses, etc.. [2]. Normally radiation pressure forces are negligible. However, in systems where intense light intensities are used, such as focused laser beams, they play a very important role. In general, a particle can be attracted and trapped very close to the focus of the beam. Furthermore, in systems where the beam is diverging (i.e. an optical fiber) one could also expect the presence of important forces over particles.

© 2000 IEEE