Dicke-Narrowing Spectroscopy of Doubly Dressed Electromagnetically Induced Transparency and Singly Dressed Four-Wave-Mixing in a Confined Atomic System

Dicke-narrowing effect appears both in doubly dressed electromagnetically induced transparency and singly dressed four-wave-mixing lines due to the contribution of slow atoms resulting from de-excited effects of atom-wall collision and transient behaviour of atoms in a confined system. A robust recipe for high resolution spectroscopy of electromagnetically induced transparency dressed by two fields and four-wave-mixing lines comparable with the cold atoms is achievable in a thin vapour cell in experiments.