Distortion-free gain and noise correlation in sodium vapor with four-wave mixing and coherent population trapping. Academic Article uri icon


  • 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.

author list (cited authors)

  • Grove, T. T., Shahriar, M. S., Hemmer, P. R., Kumar, P., Sudarshanam, V. S., & Cronin-Golomb, M.

citation count

  • 32

publication date

  • June 1997