Abstract

With the ongoing transition from infrared (IR) imaging systems based on single detector elements or a line of detectoo-dimensional focal-plane arrays, there is an emerging need¹ for temporal modulation (chopping) of the IR scene in order to achieve full TV rate integration and to reduce 1/f noise problems. Quantum-well infrared photodetectors (QWIPs) are particularly suited for such arrays because of their ease of fabrication and high uniformity.² The design flexibility of quantum-well intersubband transitions (ISBTs) has also made them natural candidates for modulation of the IR absorption.³ In this paper, we report on the monolithic vertical integration of a bound-to-continuum detector and an electron-transfer modulator. An analysis of the required doping concentrations, layer thicknesses, and bias voltages for near-unity modulation depths, and of the compatibility with array fabrication, is also presented.

© 1995 Optical Society of America