Presented at SPIE Photonics West 2013 - spie.org/pw
In 1992 Allen et al. recognized that light beams could carry an orbital angular momentum in addition to the photon spin. This twist can be created using lenses, or holograms encoded onto liquid crystal displays. Both whole beams and single photons can carry this twist, or transfer it to particles causing them to spin.
In his talk, Light in a Twist: Optical Angular Momentum," Miles J. Padgett introduces the underlying properties and discuss a number of manifestations of orbital angular momentum. These highlight how optics still contains surprises and opportunities for manipulation, imaging and communication in both the classical and quantum worlds.
Padgett holds the Kelvin Chair of Natural Philosophy at the University of Glasgow in Scotland. His group has pioneered the understanding of light's momentum, including conversion of optical tweezers to optical spanners, the opportunity for angular momentum in optical communication, and demonstrating an angular form of the quantum EPR paradox.