PLZT ceramics electrooptic Fabry-Perot interference modulator with thermooptic bias

The electrooptic modulation of high power Ar+ laser radiation with a PLZT ceramics Fabry-Perot interference reflection and transmission modulator is described. At low intensities I-O of the incident radiation the PLZT Fabry-Perot interferometer without any additional reflective coatings on the surfaces (refractive index n approximate to 2.5, Fresnel reflections on the surfaces R approximate to 19%) provides modulation of the reflected beam in the range from 0 up to approximate to 0.45I(O), and of the transmitted beam from approximate to 0.55I(O) up to 1.0I(O). The increase of the intensity of the incident beam causes inevitable photorefraction effects, which can be avoided in the case of pulse modulation with a sequence of bipolar pulses. The bistable behaviour of the Fabry-Perot interferometer due to the pronounced thermooptic effect in PLZT ceramics causes a selfinstallation of the modulator working conditions at higher intensities (up to 1.5 W focused by a lens f = 80 mm) of the incident laser beam.