  This paper presents the nonlinear dynamics of laser cooled and trapped cesium
atoms placed inside an optical cavity and interacting with a probe light beam
slightly detuned from the 6S1/2(F=4) to 6P3/2(F=5) transition. The system
exhibits very strong bistability and instabilities. The origin of the latter is
found to be a competition between optical pumping and non-linearities due to
saturation of the optical transition.
