Physical Review A
Accelerated superradiance and collective atomic recoil lasing with a two-frequency pump
Mary M. Cola, Luca Volpe, N. Piovella
Abstract
We demonstrate that superradiance and collective atomic recoil lasing from cold atoms can be enhanced using a two-frequency pump with frequency difference twice the two-photon recoil frequency ${\ensuremath{\omega}}_{r}$. In the good-cavity regime the atoms behave as a three-recoil-level system, collectively scattering a single-frequency radiation mode. In the bad-cavity regime, the superradiant cascade through the different recoil momentum states is strongly accelerated. The emitted radiation shows a discrete spectrum whose harmonics are separated by $2{\ensuremath{\omega}}_{r}$ and generated by transitions between adjacent momentum levels.