Dual-Comb Scanning Spectrometer for Remote Sensing of Traces of Explosives

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&#x2013;<inline-formula> <tex-math notation="LaTeX">$8~\mu \text{g}$ </tex-math></inline-formula>/cm² in a scanning regime and 2&#x2013;<inline-formula> <tex-math notation="LaTeX">$3~\mu \text{g}$ </tex-math></inline-formula>/cm² with stationary beam in reflection&#x2013;absorption and backscattering modes.