Grazing-angle intersubband absorption and photocurrent in thick n-doped GaAs multiple-quantum-well structures

Abstract

We present an experimental study of the absorption and photocurrent in a thick n-doped GaAs/AlGaAs quantum-well infrared photodetector (QWIP). At grazing-angle incidence, we observed peaks that are far detuned from the intersubband resonance. These phenomena can be well explained by the resonant coupling of the light to leaky waveguide modes in the multiple-quantum-well stack. We propose taking advantage of these waveguiding effects for the design of QWIP structures operated at a high temperature.