Optimization of corrugated QWIPs for high speed infrared imaging

Corrugated quantum well infrared photodetectors (C-QWIPs) offer simple detector architecture for large format infrared focal plane arrays. The detector relies on inclined sidewalls to couple normal incident light into the absorbing material. In this work, we describe the light coupling characteristics of C-QWIPs based on a simple geometrical-optics model and a rigorous modal transmission-line model. Based on these two theoretical models, we optimize the detector structure toward a large quantum efficiency η. In addition, we investigated material structures that give both high photoconductive gain and large spectral bandwidth. Combining these two material properties with a large η offered by the corrugated structure, the detector photocurrent can be greatly increased, which will be useful in high speed infrared imaging.