High-power extremely shallow quantum-well modulators

It is found that extremely shallow quantum wells (QWs) are capable of modulating high-intensity light due to the enhanced sweep out of photogenerated carriers. These QWs are especially well suited for use in self-electrooptic effect devices (SEEDs) due to the existence of a strong room-temperature exciton that ionizes rapidly with field. For a 3- mu m diameter spot, bistable reflectivity changes (for a symmetric-SEED arrangement using a 7 V power supply) of 18% at 1 mW (24 kW/cm/sup 2/), 10% at 2 mW, and 4% at 3 mW were obtained, compared to 6.8% at 0.4 mW for the previous best sample.<
>