Abstract

As we have shown,^1,2several output conditions can be obtained from a hybrid optical bistable device when twisted nematic liquid crystal cells are employed as nonlinear elements. Depending on the amplification factor and/or the bias polarization, with a linear feedback, several different oscillations have been obtained having frequencies ranging from ~35 to 350 Hz. We extend these results to the case of a nonlinear feedback. Three different feedback devices have been employed. Both are represented in Fig. 1 where the black box corresponds, in the first case, to a classical electronic oscillator with different waveform and frequency outputs. In the second case, a Schmitt trigger works as the nonlinear feedback mechanism. In the third case, a hybrid electrooptical bistable device is added to the system.

© 1983 Optical Society of America