Dual-Comb Scanning Spectrometer for Remote Sensing of Traces of Explosives
J. Macarthur, Jakob Hayden, Matthew Warden, Christopher Carson, David Stothard, Vasili G. Savitski
Abstract
Standoff scanning dual-comb spectroscopy of explosive materials is demonstrated with quantum cascade lasers at <inline-formula> <tex-math notation="LaTeX">$\sim 8~\mu \text{m}$ </tex-math></inline-formula>. The proof-of-concept of the spectrometer, capable of the detection and identification of explosive materials at a distance of 3 m, has a detection limit of cyclotrimethylenetrinitramine (RDX) and pentaerythritol tetranitrate (PETN) on various surfaces of 5–<inline-formula> <tex-math notation="LaTeX">$8~\mu \text{g}$ </tex-math></inline-formula>/cm<sup>2</sup> in a scanning regime and 2–<inline-formula> <tex-math notation="LaTeX">$3~\mu \text{g}$ </tex-math></inline-formula>/cm<sup>2</sup> with stationary beam in reflection–absorption and backscattering modes.