title: High-precision molecular interrogation by direct referencing of a quantum-cascade-laser to a near-infrared frequency comb.
abstract: This work presents a very simple yet effective way to obtain direct referencing of a quantum-cascade-laser at 4.3 μm to a near-IR frequency-comb. Precise tuning of the comb repetition-rate allows the quantum-cascade-laser to be scanned across absorption lines of a CO2 gaseous sample and line profiles to be acquired with extreme reproducibility and accuracy. By averaging over 50 acquisitions, line-centre frequencies are retrieved with an uncertainty of 30 kHz in a linear interaction regime. The extension of this methodology to other lines and molecules, by the use of widely tunable extended-cavity quantum-cascade-lasers, paves the way to a wide availability of high-quality and traceable spectroscopic data in the most crucial region for molecular detection and interrogation.
authors.affiliation: Dipartimento di Fisica, Politecnico di Milano, Milano, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Gatti
authors.forename: A
authors.initials: A
authors.lastname: Gambetta
authors.forename: A
authors.initials: A
authors.lastname: Castrillo
authors.forename: G
authors.initials: G
authors.lastname: Galzerano
authors.forename: P
authors.initials: P
authors.lastname: Laporta
authors.forename: L
authors.initials: L
authors.lastname: Gianfrani
authors.forename: M
authors.initials: M
authors.lastname: Marangoni