Pancharatnam geometric phase originating from successive partial projections

HEMA RAMACHANDRAN P. HARIHARAN

Rajaram Nityananda

José Lages, Remo Giust, J. M. Vigoureux

Eliahu Cohen, Hugo Larocque, Frédéric Bouchard +3 more

P. Hariharan, Hema Ramachandran, Kattera A. Suresh +1 more

We describe an interferometer based on the Pancharatnam phase in which the extra phase introduced is of purely geometric origin, with no contributions from the dynamic phase. We use a cholesteric liquid crystal film as a circular analyser, and a sheet polarizer as a linear analyser, to project each polarization state on the next one. This experiment can also be viewed as a demonstration of Berry's phase arising from quantum measurements.

Luis A. Garza-Soto, Nathan A. Hagen, Dorilian Lopez-Mago

While Pancharatnam discovered the geometric phase in 1956, his work was not widely recognized until its endorsement by Berry in 1987, after which it received wide appreciation. However, because Pancharatnam's paper is unusually difficult to follow, his work has often been misinterpreted as referring to an evolution of states of polarization, just as Berry's work focused on a cycle of states, even though this consideration does not appear in Pancharatnam's work. We walk the reader through Pancharatnam's original derivation and show how Pancharatnam's approach connects to recent work in geometric phase. It is our hope to make this widely cited classic paper more accessible and better understood.