An Adaptive Technique for Automatic Region Detection and Extraction of FTIR Spectral Material Absorption for Mid-Wave Infrared Microsphere-Lens-Enhanced Type II Strained Layer Super-Lattice Photodetectors

In general, spectral absorptions are known to negatively affect photodetector Fourier Transform Infrared Transform (FTIR) responses. In this paper, we present an adaptive technique for automatic spectral region detection, absorption modeling and extraction. We show how a combination of several automated signal processing steps, including automatic piecewise-polynomial models derivation in addition to an automatic adaptive boundary based spectral absorption removal, leads to an effective determination of overall FTIR signal performance improvement. Our results show that for different types of lens materials the proposed adaptive algorithm can automatically quantify the increase in the detector sensitivity while additionally finding material-based absorptions and reducing their adverse effects across the MWIR band.