Rotating photons: the angular momentum of light from the spin form

Seminario del Dpto. de Física de los Materiales
UAM
Viernes 12 de Febrero de 2010. 15:00 h.
Sala de seminarios del Dpto. Física de Materiales, C04
Rotating photons: the angular momentum of light
from the spin form to the orbital form,
and related quantum effects
Prof. Lorenzo Marrucci
Dipartimento di Scienze Fisiche
Università degli Studi di Napoli Federico II
Napoli, Italy
Abstract:
A beam of light, or even a single photon, can carry two different forms of
angular momentum: the "spin" form, associated with a circular polarization, and
the "orbital" form, associated with a helical wavefront and with an optical
vortex at the beam axis.
Few years ago, we have found that an optical medium that is both birefringent
and inhomogeneous can couple these two forms of angular momentum to each
other and thus give rise to a "conversion" from one form to the other. This
effect, in turn, can be exploited for controlling the quantum state of the photon
angular momentum, thus opening the way to the demonstration of several novel
quantum processes