Logical and relational operations of optical bistable devices operating without external bias

We report successful optical realization of both logical and relational functionality using a multiple quantum well optical bistable device operating without external bias and a simple experimental setup. For the nonbiased optical bistability, we employed extremely shallow quantum wells and asymmetric Fabry-Perot cavity structure in self electro-optic effect device. The change between logical and relational mode was simply realized by controlling the intensity of the optical bias beam into devices following the basic operation principle of the optical bistability.