Physical Review A
Physics in counterpropagating light-beam devices: Phase-conjugation and gain concepts in multiwave mixing
Martine Le Berre, Elisabeth Ressayre, Andree A. Tallet
Abstract
The physics of Raman-type self-oscillations in highly dispersive saturable two-level-medium devices is revisited by using the gain and reflectivity matrices. The probe gain when two identical pumps counterpropagate through a two-level system is demonstrated to be very different from the gain for a probe in a one-way device, and typically peaked near a frequency twice the one-way Rabi frequency, while multiwave mixing displays a generalized mirror behavior of the atomic cell. The multimode instability in a Fabry-P\'erot interferometer is also discussed and shown to be mainly a result of counterpropagating probe coupling while the coupling between copropagating probe and idler is negligible.