Generation of polarization-entangled photon pairs by a single crystal interferometric source pumped by femtosecond laser pulses

摘要

Photon pairs highly entangled in polarization have been generated under femtosecond laser pulse excitation by a type-I crystal source operating in a single-arm interferometric scheme. The relevant effects of temporal walkoff existing in these conditions between the ordinary and extraordinary photons were experimentally investigated. By introducing a suitable temporal compensation between the two orthogonal polarization components, highly entangled pulsed states were obtained.