title: Distortion-free gain and noise correlation in sodium vapor with four-wave mixing and coherent population trapping.
abstract: We observed optical gain as great as 30 with nearly distortion-free beam propagation in optically dense sodium vapor, using four-wave mixing. Moreover, 15-dB classical noise correlations were seen in the amplified probe and conjugate beams. To achieve this performance in such a strongly absorbing medium, one must suppress unwanted absorption and self-focusing effects. This is accomplished with coherent population trapping.
authors.forename: T T
authors.initials: TT
authors.lastname: Grove
authors.forename: M S
authors.initials: MS
authors.lastname: Shahriar
authors.forename: P R
authors.initials: PR
authors.lastname: Hemmer
authors.forename: P
authors.initials: P
authors.lastname: Kumar
authors.forename: V S
authors.initials: VS
authors.lastname: Sudarshanam
authors.forename: M
authors.initials: M
authors.lastname: Cronin-Golomb