Open AccessDual-comb mid-infrared spectroscopy with free-running oscillators and absolute optical calibration from a radio-frequency reference
Author(s) -
Oguzhan Kara,
Z. Zhang,
Tom Gardiner,
Derryck T. Reid
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.016072
Subject(s) - optics , hitran , femtosecond , spectroscopy , materials science , calibration , frequency comb , near infrared spectroscopy , absorption spectroscopy , laser , physics , quantum mechanics
By using free-running independent femtosecond OPOs with a repetition-rate difference of 500 Hz we demonstrate methane absorption spectroscopy with spectral coverage simultaneously spanning the methane P, Q and R branches and with a resolution of 0.5 cm -1 . Absolute optical frequency calibration with an accuracy of 0.25 cm -1 (0.27 nm) is achieved from simultaneous repetition-rate and carrier-envelope-offset frequency measurements, without the need for any optical reference. The calibration technique allows registration and averaging of consecutively acquired dual-comb spectra, leading to a high quality and low-noise absorbance measurement in good agreement with the HITRAN database.