Tunable Infrared Photodetectors for MASINT Applications

光谱图像在过去的十年中已经成为应用于测量和信号情报（MASINT）问题的最强大的工具之一。传统的成像传感器测量场景中每个像素处的宽波长范围内的辐射率。光谱传感器通过测量光谱的感兴趣区域上的多个光谱带中的辐射率来向观察者提供更多信息。这里提出的红外探测器代表了光谱成像和其他MASINT应用的传感器的革命性变化。如下所述，可以简单地通过改变FPA的偏置电压来控制和调整光谱响应。这种光谱灵活性将允许使用相同的探测器执行双色，多光谱和低分辨率高光谱图像，并且光谱灵敏度，带宽和波段数量可以随意独立控制。 基于子带间跃迁的新型正入射中红外量子点（QD）探测器是这项新技术的核心。这些纳米级的自组装检测器已经显示出具有依赖于电压偏置的可调谐光谱特性的广泛响应。在这项工作中，该团队强调1）控制QD探测器的光谱响应和可维持性，2）理解QD探测器阵列的性能特征，包括噪声和像素间的不均匀性，以及3）如何使用这种新型传感器来执行自适应光谱成像该团队包括来自少数民族服务机构的代表性不足的学生。

Spectral imagery has emerged in the past decade as one of the most powerful tools to be appliedto 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.