Phys.org October 8, 2018
An international team of researchers (UK, USA – industry) was able to identify 11 white powder samples using their infrared laser system. No samples or disturbance of the powders were required, and they could be identified from up to one metre away. They illuminated each sample with broadband coherent light in the 8–9-µm band. Similarities between different spectra were quantified using Pearson’s correlation coefficient, confirming that spectral features in the 8–9-µm wavelength region were sufficient to discriminate between all eleven powders evaluated in the study. The researchers believe that the identification system will prove most useful for a different set of substances. The research could be useful in a range of scenarios, such as detecting counterfeit pharmaceuticals, conducting foodstuff analysis or identifying hazardous material like explosive residue…read more. Open Access TECHNICAL ARTICLE
(a,b) Prepared powder samples, and (c) illumination geometry used in the experiment. Credit: Optics Express (2018). DOI: 10.1364/OE.26.025364