Feature

Electromagnetically Induced Transparency in Solids

Yang Zhao, Dept. of Electrical and Computer Engineering, Wayne State Univ., Detroit, Mich., and Philip Hemmer, Rome Laboratory, Hanscom AFB, Mass.

Field-induced quantum interference can lead to lasing without inversion (LWI) and electromagnetically induced transparency (EIT) for the resonant enhancement of nonlinear effects with reduced absorption. Until recently, experimental studies of quantum interference have mainly focused on atomic gas media. Now EIT is reported in ruby and Pr+ doped YSO, using three-level systems wherein two of the levels are coupled by a strong electromagnetic field. These results significantly advance the understanding of quantum coherence and interference in solids, and serve as a valuable intermediate step in the development of inversion-less solid-state lasers and low power optical switches.