Abstract

Optoelectronic devices which use large absorption changes in quantum wells typically use the Quantum Confined Stark Effect (QCSE).¹ Negative differential absorption modulation (NDAM), which entails high absorption at zero field and lower absorption at large bias, is limited by the shifting of light hole excitons. Although the excitons are quenched with high bias, the devices require very high electric fields to produce any substantial absorption drop. Here we demonstrate a method for obtaining a higher degree of NDAM than is obtainable through the QCSE and at a far lower voltage than is typically required by the QCSE. In addition, at other wavelengths the same device displays positive differential absorption modulation (PDAM). Finally, the devices can display absorptive bistability. These characteristics make it uniquely suited for use in vertical cavity modulators², self electro-optic effect devices (SEEDs)³, and waveguide devices, as well as a whole host of new devices.

© 1993 Optical Society of America