Phase conjugation with gaussian beams

Sheau‐Shong Bor

Steve Stuut, Murray Sargent

The effects of Gaussian-beam averaging with various apertures are derived for three-wave mixing in nonlinear two-level media. The model studies the phase transition from plane-wave to pure Gaussian saturation. Applications to phase conjugation, beat-frequency spectroscopy, and laser–optical-bistability instability phenomena are considered. The Gaussian beams are seen to reduce or wash out dynamic Stark splittings observed for plane-wave saturation. For strong saturation, the side-mode gain/absorption coefficient versus detuning yields slightly larger gain for the homogeneously broadened laser instability but substantially curtailed gain for the corresponding absorptive optical-bistability instability.

J. Auyeung, Avigail Yariv

Kei Hagiwara, Atsushi Okamoto, Hiroyuki Kaneko +2 more

With progress in phase conjugate optics, studies on forward four-wave mixing have been actively carried out. From the practical optical system design point of view, it is important to understand the angular dependence of phase conjugate intensity when pumping beams with limited spot size are used, especially with beam separation taken into consideration. In this paper, the angular dependence of phase conjugate intensity distribution is theoretically analyzed for the first time, in forward four-wave mixing when an optical Kerr medium is used. First, the phase conjugate intensity is calculated for a nonlinear medium thinner than the overlapping region of two pumping beams, where the intensity is relatively low. The results are used to calculate the output angle of the phase conjugate beam against the z-axis and the azimuth angle in the x-y plane. Then, a similar analysis is conducted for a medium sufficiently thick to cover the interaction region of two pumping beams. The differences between the above two cases are described and comparison with plane-wave pumping is made. Finally, the effects of spot size and curvature variation with Gaussian beam pumping on conjugate beam intensity are discussed for the case of a thick medium. © 1997 Scripta Technica, Inc. Electron Comm Jpn Pt 2, 80(4): 67–75, 1997

Jun-ichi Sakai

Concetto R. Giuliano, David A. Rockwell