OPTICAL BISTABILITY IN PLZT CERAMICS

Optical bistability in PLZT ceramics due to the Ar+ laser induced heat ing and changes of the optical thickness of a plane parallel PLZT plat e (behaving as the Fabry-Perot cavity) is observed. Such PLZT ceramics plate is used also as an extracavity laser mirror. Thermooptical tuni ng of the mirror causes a non-liner behaviour of such system. A negati ve feedback brought by the thermooptic mirror can be used to stabilise the laser output. On the contrary, the competitive action of the PLZT plate as the coupled mirror, on one hand, and as the non-linear Fabry -Perot cavity, on the other hand, can cause periodical fluctuations in the output of the laser.