Abstract

Optical modulators with a high contrast ratio are desirable for use in optical information processing applications. Devices based on semiconductor multiple quantum wells are of particular interest because of the possibility of combining modulators with detectors and electronic components on a single substrate to make high-speed smart-pixel arrays. However, it is difficult to obtain large contrast ratios in conventional MQW modulators, which function by using the quantum confined Stark effect to modify the absorption coefficient of the MQW. For example, a typical p-i(MQW)-n modulator has a contrast ratio of 3:1 to 5:1, although contrast ratios as high as 10:1 have been obtained. Fabry-Perot cavities have been used to increase the contrast ratio to 100:1, but at the expense of optical bandwidth.

© 1995 Optical Society of America