Dual-comb spectroscopy for the characterization of laboratory flames
Abstract
Optical spectroscopy, in particular dual-comb (DC) spectroscopy, is a critical, non-invasive tool for combustion diagnostics, offering high precision and calibration-free advantages. However, its implementation remains challenging, especially in the mid-infrared region. This work presents the development of a robust DC spectroscopic system based on electro-optical (EO) frequency comb generators and difference frequency generation (DFG), specifically designed for the characterization of laboratory flames. Operating at a center wavelength of 3427.43 nm, the system utilizes a differential detection strategy to enable precise, calibration-free measurements of unburned methane () concentrations in a McKenna burner. The experimental results demonstrate an estimated detection limit of 1.1 ppm for a 1 m path length and effectively resolve spatial concentration gradients across the combustion region. Furthermore, the system's high temporal resolution allowed for the identification of dynamic combustion instabilities, including self-sustained pulsations and fuel leakage under fuel-lean conditions. These findings validate the proposed EO architecture as a flexible and highly sensitive tool for advanced flame characterization.
Keywords
Cite
@article{arxiv.2512.21093,
title = {Dual-comb spectroscopy for the characterization of laboratory flames},
author = {Bernat Frangi and Laura Monroy and Aldo Moreno-Oyervides and Oscar E. Bonilla-Manrique and Mariano Rubio-Rubio and Mario Sanchez-Sanz and Pedro Martín-Mateos},
journal= {arXiv preprint arXiv:2512.21093},
year = {2026}
}