Broadband comb spectroscopy through spectral envelope shaping.

Abstract

Optical frequency combs have facilitated fast and compact multi-component chemical analysis due to their broad spectral bandwidth. Although dual-comb spectrometers are an established implementation of this technology, their design requires a pair of matched combs with high mutual coherence, making the system considerably complex. In this study, we propose and implement a rapid, compact and broadband spectroscopy technique that operates without moving components, leveraging the stability, controllability and speed of a single Quantum Wwalk Ccomb laser. By using a comb based on a Quantum Cascade Laser, emitting within the molecular fingerprint region of the mid-infrared spectrum, we build a non-interferometric setup for the targeted and non-targeted analysis of various organic solvent vapours. With a time resolution as small as 10 μs and a high dynamic range reaching three orders of magnitude in concentration, this approach is suitable for the real-time analysis of chemical kinetics.