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Multimode Imaging in the Thermal Infrared for Chemical Contrast Enhancement. Part 1: Methodology

NCJ Number
Analytical Chemistry Volume: 82 Issue: 20 Dated: 2010 Pages: 8412-8420
Heather Brooke; et al
Date Published
9 pages

This project combined a thermal light source with a conventional thermal infrared camera, alternating current (AC) detection methods, and chemical filtering of the infrared (IR) light to generate several imaging modalities in a simple manner.


The project demonstrated that digital lock-in amplifier techniques can increase the chemical contrast in an active thermal infrared image, using both reflectance and thermal re-emission. This method was shown to be useful for visualizing thin coatings on fabrics that are invisible to the eye. The project also took advantage of a “like-detects-like” chemical filtering approach to chemical selectivity for the purpose of chemical identification using a broadband thermal detector. (publisher abstract modified)