Non-linear thermooptical self-action effects in relaxor ferroelectrics

Non-linear behaviors of a laser system with a thermooptically and electrooptically tuneable Fabry-Parot interferometer (FPI) on relaxer type ferroelectric PLZT ceramics are reported: the optical bistability, the bistable optical trigger - both taking place at conditions when the retroreflected beam is attenuated and does not effect lasing. The optical feedback provided by the reflected beam returned into the laser cavity causes other kind of non-linear phenomena: the laser output becomes a discontinuous pump function, and the electrooptical tuning of the FPI allows to switch the output power between bistable lasing levels.