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Updated: May 29, 2026

Direct Imaging of Laser-driven Ultrafast Molecular Rotation
Published on: February 4, 2017
Noncontact optical detection of explosive particles via photodissociation followed by laser-induced fluorescence
C M Wynn1, S Palmacci, R R Kunz
1Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, MA 02420, USA. cwynn@ll.mit.edu
Abstract:
High-sensitivity (ng/cm²) optical detection of the explosive 2,4,6-trinitrotoluene (TNT) is demonstrated using photodissociation followed by laser-induced fluorescence (PD-LIF). Detection occurs rapidly, within 6 laser pulses (~7 ns each) at a range of 15 cm. Dropcasting is used to create calibrated samples covering a wide range of TNT concentrations; and a correspondence between fractional area covered by TNT and PD-LIF signal strength is observed. Dropcast data are compared to that of an actual fingerprint. These results demonstrate that PD-LIF could be a viable means of rapidly and remotely scanning surfaces for trace explosive residues.
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