Two color control of spontaneous emission from a single-channel system

Abstract

We propose a scheme for the control of spontaneous emission, employing a single spontaneous channel, the decaying state of which is coupled to two long living states by two laser fields. This scheme provides a controllable way for the equivalent realization of a two-channel system and thus is easier to implement. While effects obtained previously for the two channel system such as selective elimination and spectral narrowing are preserved, two new effects are predicted. A three-peaked spectrum alternatively appears with a single ultrasharp line as either of two driven transitions is slowly detuned from one-photon resonance. Double dark lines occur in the spontaneous emission spectrum when the two driven transitions are off two-photon resonance. We also show that the phase control of spontaneous emission can be realized under significantly looser conditions.