We are developing a technology for stand-off detection based on photo-thermal infrared imaging spectroscopy (PT-IRIS). In this approach, one or more infrared (IR) quantum cascade lasers are tuned to strong absorption bands in the analytes and directed at the sample while an IR focal plane array is used to image the subsequent thermal emissions. In this paper we present recent advances in the theory and numerical modeling of photo-thermal imaging and spectroscopy of particulates on flat substrates. We compare the theoretical models with experimental data taken on our mobile cart-based PT-IRIS system. Synthetic data of the photo-thermal response was calculated for a wide range of analytes, substrates, particle sizes, and analyte mass loadings using their known thermo-physical and optical properties. These synthetic data sets can now be generated quickly and were used to accelerate the development of detection algorithms. The performance of detection algorithms will also be discussed.

Date Published: 19 May 2015
PDF: 12 pages
Proc. SPIE 9455, Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) Sensing XVI, 94550I (19 May 2015); doi: 10.1117/12.2177270

Published in SPIE Proceedings Vol. 9455:
Chemical, Biological, Radiological, Nuclear, and Explosives (CBRNE) Sensing XVI
Augustus Way Fountain III, Editor(s)