Abstract

It is well established that a light beam may possess orbital angular momentum (OAM) due to its spatial phase distribution. In 1992 the OAM for Laguerre-Gaussian (LG) laser modes was theoretically derived to be lħ where / is the azimuthal mode index.¹ The transfer of OAM to absorptive trapped particles has been demonstrated experimentally using LG beams.² However, a much wider family of beams, which have to date not been explored, possess orbital angular momentum. In this work, we demonstrate experimentally for the first time, that a high order Bessel beam possesses OAM. We demonstrate transfer of OAM from such a beam to trapped transparent particles in optical tweezers. Additionally, we examine theoretically, within a rigorous vectorial treatment, the local angular momentum density for a high order Bessel beam (HOBB) and find local variations in this density when compared to LG beams.

© 2002 Optical Society of America