We report an experimental observation of the enhancement of nondegenerate four-wave mixing (NDFWM) based on electromagnetically induced transparency (EIT) in a lambda-type three-level system of rubidium atoms. We measured both the linear susceptibility Im χD(1) (absorption) and the third-order nonlinear coefficient χD(3) separately for the NDFWM process at a low atomic density. We found that, owing to the EIT effect, the linear absorption term Im χD(1) is greatly reduced, while the nonlinear generation term χD(3) is resonantly enhanced, permitting us to observe a significant enhancement of the NDFWM signal in an optically dense medium.
© 1996 Optical Society of America
Yong-qing Li and Min Xiao, "Enhancement of nondegenerate four-wave mixing based on electromagnetically induced transparency in rubidium atoms," Opt. Lett. 21, 1064-1066 (1996)