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Proceedings Paper

Highly sensitive standoff detection and identification of traces of explosives and of biological and chemical agents
Author(s): Alexander Portnov; Illana Bar; Salman Rosenwaks
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Paper Abstract

Our experiments focused on monitoring the signal obtained from diffuse reflections of forward-generated coherent anti-Stokes Raman scattering (CARS), occurring in different samples, referred to as "backward-CARS" (B-CARS). The methodology of B-CARS was developed and the feasibility of using it as a spectroscopic tool for standoff detection of particles of explosives and related compounds studied. Signals of both the B-CARS and spontaneous Raman scattering under similar conditions were monitored to compare their sensitivities. In addition, the dependence of the B-CARS signal on the distance was measured at short ranges and the standoff detection capabilities of the method at long distances estimated. The measurements imply that B-CARS allows favorable detection as compared to Raman. However, an inherent drawback of the developed narrowband B-CARS method is the need to scan the Stokes beam frequency to monitor the different vibrational levels of the detected species. We therefore embarked on a broadband B-CARS method (patent pending) which is based on the application of a sub-ns ultra-broadband laser source for the Stokes beam and enables to monitor simultaneously a wide span of vibrational transitions of the detected species.

Paper Details

Date Published: 12 October 2010
PDF: 11 pages
Proc. SPIE 7838, Optics and Photonics for Counterterrorism and Crime Fighting VI and Optical Materials in Defence Systems Technology VII, 78380D (12 October 2010); doi: 10.1117/12.863471
Show Author Affiliations
Alexander Portnov, Ben-Gurion Univ. of the Negev (Israel)
Illana Bar, Ben-Gurion Univ. of the Negev (Israel)
Salman Rosenwaks, Ben-Gurion Univ. of the Negev (Israel)


Published in SPIE Proceedings Vol. 7838:
Optics and Photonics for Counterterrorism and Crime Fighting VI and Optical Materials in Defence Systems Technology VII
Colin Lewis; Doug Burgess; Roberto Zamboni; François Kajzar; Emily M. Heckman, Editor(s)

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