Abstract

Mariy applications on the coherent excitation of optical material have been developed to date. The quantum interference effects in a multi-level system have remarkable future: the electro-magnetically induced transparency, lasing without inversion,¹ refractive index enhancement, and group velocity control etc. The coherence of optical materials can be excited when Rabi frequency is grater than absorption line width i.e. ω_R >ω_a In historically, these experiments only demonstrated in hyper fine structure or ultra-narrow absorption line in atomic gas media, solid hydrogen or rare earth ion doped crystals at the liquid helium temperature.

© 2001 Optical Society of America