Abstract

We present preliminary results on a quantum-well (QW) light modulator operated all optically in the sense that one write laser beam strongly modulates a read beam resonant to a QW exciton. The principle of operation of the device is as follows: every period of the heterostructure contains three QWs are designed in such a way that after above-bandgap photoexcitation, a large fraction of the photogenerated electrons and holes tend to separate and accumulate in the exterior QWs. The resulting space-charge field has its maximum in the region in between and acts through the quantum confined Stark effect (QCSE)¹ on the exciton resonance of the central QW.

© 1995 Optical Society of America