Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE
Observation of geometric phase in optical spectroscopy
H.-R. Xia, Stephen D. Swartz, J. L. Hall
Abstract
We report the first observation of the geometric phase of a quantum system driven by laser fields. The observable geometric phase effects in optical FM spectroscopy, here distinguished from various known lineshape changes due to spectroscopic or technical causes, are characterized by the following aspects: (1) Dramatic lineshape variation of the optical heterodyne signal due to a monotonic signal phase change with increasing probe power; (2) The lineshape changes are associated with a nearly pure phase-change effect; and (3) The phase-change rate with probe power depends on rf sideband frequency, and less strongly on the rf modulation index.