Pacific Northwest National Laboratory (PNNL) has active programs investigating the optical absorption strengths of several types of molecules including toxic industrial chemicals (TICs), microbiological threats such as bacteria, as well as explosives such as RDX, PETN and TNT. While most of our work has centered on the mid-infrared domain (600 to 6,500 cm-1), more recent work has also included work in the far-infrared, also called the terahertz (THz) region (500 to ~8 cm-1). Using Fourier transform infrared spectroscopy, we have been able to compare the relative, and in some cases absolute, IR/THz cross sections of a number of species in the solid and liquid phases. The relative band strengths of a number of species of interest are discussed in terms of both experimental and computational results.
Revised: March 13, 2008 |
Published: November 30, 2007
Citation
Johnson T.J., N.B. Valentine, P.L. Gassman, D.A. Atkinson, S.W. Sharpe, and S.D. Williams. 2007.On the Relative Utility of Infrared (IR) versus Terahertz (THz) for Optical Sensors. In Chemical and Biological Sensors for Industrial and Environmental Monitoring III, Proceedings of the SPIE, edited by KJ Ewing, et al., 6756, 1-7. Bellingham, Washington:SPIE.PNNL-SA-57352.doi:10.1117/12.754009