Abstract

Optical modulators/switches with high speeds, high extinction ratios and small device sizes are fundamentally important in optical communications and optical signal processing systems[1],[2]. In recent years, people have made switches by using free carrier injection[3],[4]. Unfortunately, using forward biased carrier injection the switch speed is limited since the carrier lifetime is long, and the current spreading will smear the index change to give a poor reflection. In order to overcome these problems, it is necessary to pursue some new kinds of switches. Some work has been presented that shows switching operation in a reverse biased GalnAsP/InP multiple quantum well optical switch which has a p-n junction in the intersection region by a regrowth technique[5]. In this paper we propose an optical modulator/switch which uses the concept of reflection from a depletion edge that can be translated across the waveguide. We also describe initial calculated and experimental results.

© 1989 Optical Society of America