Tunable Infrared Photodetectors for MASINT Applications

在过去的十年中，光谱图像已经成为应用于测量和信号智能(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在广泛波长范围内的辐射。光谱传感器通过测量光谱中感兴趣区域的多个光谱波段的辐射度，为观察者提供更多的信息。这里提出的红外探测器代表了用于光谱图像和其他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同一探测器执行双色、多光谱和低分辨率的高光谱图像，并且光谱灵敏度、带宽和波段数量可以随意独立控制。一种基于子带间跃迁的新型垂直入射中红外量子点(QD)探测器是这项新技术的核心。这些纳米尺度的自组装探测器表现出了广泛的响应，具有依赖于电压偏置的可调光谱特性。在这项工作中，团队强调1)控制QD探测器的光谱响应和稳定性，2)了解QD探测器阵列的性能特征，以包括噪声和像素间的不均匀，以及3)如何使用这种新型传感器进行自适应光谱成像团队包括来自主要少数群体服务机构的未被充分代表的群体的学生。

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.