LIGHT-SHIFT-INDUCED LEVEL-CROSSING AND RESONATORLESS OPTICAL BISTABILITY IN SODIUM VAPOR

It is demonstrated experimentally and theoretically that a light-shift -induced level crossing in an oblique magnetic field results in a nonm onotonous dependency of the transmission of a sodium vapor cell on the input power. If feedback by a single plane mirror is added, bistabili ty of the transmission and of the beam profile (resonatorless transver se optical bistability) is observed. The origin of the bistable behavi or and the parameter dependencies is explained by the properties of th e homogeneous solution. Numerical simulations with a Gaussian incident beam reproduce well the switching behavior of the beam profile found in the experiment.