Tunable Infrared Photodetectors for MASINT Applications

University Of New Mexico, Albuquerque NM

Investigators

Abstract

Spectral imagery has emerged in the past decade as one of the most powerful tools to be applied to the problem of measurement and signals intelligence (MASINT). A conventional imaging sensor measures the radiance over a broad range of wavelengths at every pixel in a scene. A spectral sensor provides more information to the observer by measuring the radiance in a number of spectral bands across an interesting region of the spectrum. The infrared detectors proposed here represent a revolutionary change in sensors for spectral imagery and other MASINT applications. As discussed below, the spectral response can be controlled and adapted simply by changing the bias voltage of the FPA. This spectral agility will allow two-color, multispectral, and low-resolution hyperspectral imagery to be performed with the same detector, and the spectral sensitivity, bandwidth, and number of bands can be independently controlled at will. A novel, normal incidence mid-infrared quantum dot (QD) detector based on intersubband transitions is at the heart of the new technology. These nanoscale, self-assembled detectors have shown a broad response with voltage bias dependent tunable spectral characteristics. In this effort, the team emphasize 1) controlling the spectral response and tenability of the QD detectors, 2) understanding the performance characteristics of arrays of the QD detectors, to include noise and pixel-to-pixel nonuniformity, and 3) how to use this new class of sensor to perform adaptive spectral imagery The team includes students from under-represented groups at a major minority-serving institution.