Miniaturized Imaging Spectrometer Based on HgCdTe Infrared Focal Plane Arrays

To satisfy the Army"s needs for the detection and identification of chemical and biological compounds and agents present in improvised explosive devices, we propose to develop a miniaturized infrared (IR) imaging spectrometer consisting of a HgCdTe-based IR focal plane array (IRFPA) coupled with a Fabry-Perot interferometer, by combining microelectromechanical systems (MEMS) technology with HgCdTe IR detector technologies. MEMS technology will be used to tune the sensor wavelength, allowing for multiple wavelength detection. All IRFPA pixels are tuned to specific wavelengths and a hyperspectral image cube is obtained by capturing an image at each wavelength of interest. During Phase I of the project we will perform optical, electronic and system studies and will develop pattern recognition algorithms for quantitative spectral decomposition and compound identification. We will design the interferometer cavity, study the materials for Bragg reflectors and perform finite element modeling of the mechanical displacements. We will study various beam structures, simulate the electrostatic actuation and determine the optimal actuation voltages. We will build a characterization set-up to assess the sensitivity, selectivity, false positive rates and probability of detection of the sensor. These figures of merit will be compared with those obtained in standard Fourier transform setups