Spectrally Adaptive Smart Sensors Based on Nanoscale Quantum Dots

University Of New Mexico, Albuquerque NM

Investigators

Abstract

The aim of the proposed effort is to develop adaptive sensors in the mid-infrared regime (3-14 _m) for incorporation into large area focal plane arrays. Traditional infrared sensors employ either a forward-looking infrared (FLIR) imager or a Fourier transform infrared (FTIR) spectrometer. We plan to achieve this goal by developing high performance intersubband quantum dot (QD) detectors and integrating them with adaptive signal-processing algorithms to enhance their performance, tunability, and adaptability. One possible application of these sensors is detection of toxic chemical and biological agents, most of which have characteristic absorption features in this wavelength regime. Using this approach, preliminary measurements have yielded an adaptive sensor whose center wavelength can be continuously tuned from 5-8_m with a user chosen bandwidth between 0.5-2_m. We wish to further increase the operating wavelength range and optimize the bandwidth of the sensor. Intellectual Merit of the Proposed Activity: Although QD detectors provide a wide spectral coverage; the broad line width is inadequate for spectral sensing applications. Innovative post-processing schemes have been developed by Co-PIs, Tyo and Hayat, to reduce the available spectral resolution while maintaining the broad spectral coverage of the QD detectors. Besides its benefit as an enabling technique in virtually controlling the spectral response of individual detectors, another advantage of the proposed post-processing technique is that it allows the same FPA to be operated in the FLIR mode, as a two-color camera, as an MSI system, or even as a quasi HSI system. Broader Impacts Resulting from the Proposed Activity: The PIs have a commitment both to classroom education and to involving undergraduates in laboratory research. The PIs presently have six undergraduates in their research group, including two students. Additionally, results from this project will impact two new courses that have been developed by the PIs in optoelectronic devices and spectral imagery. The project would lead to a broader dissemination of knowledge in forums such as the New Mexico Nano-Science Alliance, which would aid the economic development of the state. The proposed research would also provide potential benefits to society. For example, an airborne system based on the adaptive QD sensor technology developed here could provide early detection and warning of a possible chemical agent threat and prevent loss of life.