Louisiana State University Physics & Astronomy

Laser beams are wave-like solutions of Maxwell’s equations with finite transverse extent. In addition to carrying momentum and energy, they can carry intrinsic (spin) as well as orbital angular momentum. Most lasers, however, emit the familiar Hermite-Gauss (HG) light beams that carry zero orbital angular momentum. Such laser beams have planar or spherical phase fronts. These beams can be transformed into Laguerre-Gauss (LG) family of laser beams that have twisted phase fronts. LG beams can carry nonzero orbital angular momentum and are examples of optical beams that may be described as optical vortices. Experimental realization of this scheme will be described and examples of such transformation of HG beams into LG beams will be presented and results of interference and polarization experiments revealing their fascinating phase and polarization properties will be discussed.