(Received July 3, 1978)
The theoretical and experimental examination of an electrooptic device with feedback are discussed in the paper. It is shown that many functions such as multistability, hysteresis, differential gain and limiter action are possible, on the characteristics of the optical output power versus input power, depending on the feedback gain and phase retardation. The examination of the dependence of the optical output power on phase retardation indicates that more efficient light modulation and switching may be achieved by using this device than by using the conventional light modulator. In addition, hysteresis was observed in the relation between optical output power versus phase retardation at the higher input range.