Open AccessModelocked Cavity--Enhanced Absorption Spectroscopy
Author(s) -
Titus Gherman,
D. Romanini
Publication year - 2002
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.10.001033
Subject(s) - finesse , optics , laser , materials science , femtosecond , spectrograph , absorption (acoustics) , overtone , tunable diode laser absorption spectroscopy , spectroscopy , optical cavity , tunable laser , physics , spectral line , fabry–pérot interferometer , quantum mechanics , astronomy
We demonstrate the principle of cavity enhanced absorption with femtosecond modelocked lasers. The wide spectral coverage allowed by these sources makes this a promising high-sensitivity linear absorption technique. The uniformity of the modelocked frequency comb is the feature allowing effective injection of a high finesse cavity. The smooth and stable laser spectral profile guarantees a good background for the intracavity sample absorption spectrum, recorded by a spectrograph and a linear detector array. With a modelocked Ti:Sa laser and a cavity of finesse F 420 (F/pi is the enhancement factor) we obtain a 4nm section of a weak overtone band in 40 ms with 0.2 cm-1resolution,a nd a detection limit of 2x10-7/cm/ radicalHz.