Efficient nonlinear frequency mixing using Autler-Townes splitting

Abstract

Exploring enhanced nonlinear optics based on electromagnetically induced transparency (EIT) has always been one of the striking issues in cavity quantum electrodynamics. However, it is not clear whether the validity of EIT in enhancing nonlinear processes is universal. In this paper we demonstrate an efficient frequency conversion scheme via Autler-Townes splitting, instead of the so-called EIT mechanism, in a three-level quantum system. Because the selective system can be used to implement the conventional three-level EIT phenomenon, we present a direct evidence for the breakdown of nonlinear processes assisted by EIT. This strongly suggests that previously physical insight into the application of the standard EIT technique in nonlinear optics is not sufficient enough.