Abstract

Modulation-doped system of asymmetric coupled quantum wells is shown theoretically to possess a large optical nonlinearity due to the charge transfer associated with intersubband transition. The range of parameters leading to optical bistability has been determined. A novel triple quantum well system is suggested, allowing a few orders of magnitude reduction in switching power density, to ~50 W/cm², while having a response time of <100 ps. Optically assisted transfer of up to 90% of all carriers between wells can become an operating principle of novel hybrid optoelectronic devices, incorporating the triple quantum well system into the channel of modulation-doped field-effect transistor with potential applications as fast optoelectronic switches and detectors in the 10-µm range.

© 1989 Optical Society of America