Optical anisotropy induced by two intense laser fields in sodium vapor

R. Holzner, S. Dangel

Qihuang Gong, Y. H. Zou

Alexei G. Leonov, A. A. Panteleev, А. Н. Старостин +1 more

Jing Cheng Wang

William V. Davis, Alexander L. Gaeta, Robert W. Boyd

We show that for a broad range of intensities the polarization ellipse of a laser beam can undergo rotation while propagating through an atomic vapor. The ellipse rotation is predicted to occur for the case in which the field is tuned near a J = 1/2 to J-1/2 transition of the atomic vapor and the input intensity is sufficiently strong to saturate the ground-state optical pumping but not the transition itself. Under these conditions, the ellipse rotation is independent of the laser intensity and, hence, is unlike the ellipse rotation predicted and observed by Maker and Terhune1 for a tensor nonlinear susceptibility.

Celestino J. Gaeta, Juan Francisco Lam, R. C. Lind

We have used a two-wave mixing gain process in sodium vapor to construct a self-pumped phase conjugator. This was done by forming a resonator around a quartz sodium cell equipped with Brewster angle windows. A pump beam is then directed into the sodium cell at a small angle to the longitudinal axis of the resonator. At sufficiently high cw pump intensities, the ac-Stark effect pro- vides sufficient gain to achieve oscillation. Although this gain is unidirectional it occurs on the wings of the sodium resonance so that the backward traveling optical field in the resonator does not experience loss due to sodium absorption. The counterpropagating optical fields in the resonator interact with the pump in an internal four- wave mixing process to produce a fourth optical field (phase conjugate to the pump field). Our experiment was conducted at the sodium D2 resonance. The pump laser was a 699 autoscan single frequency ring dye laser providing pump intensities up to several hundred watts per square centimeter.