Storage and Retrieval of a Weak Optical Signal Improved by Spontaneously Generated Coherence in an Atomic Assemble

Abstract

We investigate the reversible storage of a weak single-mode light signal in a Λ-type three-level atomic system with spontaneously generated coherence (SGC) and pumped by an incoherent field. The scheme is phase-dependent. If the phase of the controlling field is set oppositely to that of the signal field, the combination of SGC with weak pump overcomes the drawback of incompletely retrieval in the conventional scheme, leading to 100% retrieval fidelity or even to the amplification of the retrieved signal with respect to its initial one.