Multicolor quantum dots-in-a-well focal plane arrays

This paper discusses recent and future advancements in the field of quantum dots-in-a-well (DWELL) focal plane arrays (FPAs). Additionally, for clarity sake, the fundamentals of FPA figures of merit are reviewed. The DWELL detector represents a hybrid between a conventional quantum well photodetector (QWIP) and a quantum dot (QD) photodetector (QDIP). This hybridization, where the active region consists of QDs embedded in a quantum well (QW), grants DWELLs many of the advantages of its components. This includes normally incident photon sensitivity without gratings or optocoupers, like QDIPs, and reproducible control over operating wavelength through 'dial-in recipes' as seen in QWIPs. Conclusions, drawn by the long carrier lifetimes observed in DWELL heterostructures using femtosecond spectroscopy, have recently backed up by reports of high temperature operation results for DWELL FPAs. This paper will conclude with a preview of some upcoming advances in the field of DWELL focal plane arrays.