A narrow-linewidth, frequency-stabilized OPO for sub-Doppler molecular spectroscopy around 3 µm
Authors: Ricciardi I., De Tommasi E., Maddaloni P., Mosca S., Rocco A., Zondy J.-J., De Rosa M., De Natale P.
Autors Affiliation: INO–CNR, Istituto Nazionale di Ottica, Sezione di Napoli, and LENS, European Laboratory for Nonlinear Spectroscopy, Via Campi Flegrei 34, I-80078 Pozzuoli (NA), Italy; Laboratoire Commun de Metrologie LNE-CNAM, 61 rue du Landy, 93210 La Plaine Saint-Denis, France; INO–CNR, Istituto Nazionale di Ottica, Largo E. Fermi 6, I-50125 Firenze, Italy and LENS, European Laboratory for Nonlinear Spectroscopy, Via N. Carrara, I-50019 Sesto Fiorentino (FI), Italy
Abstract: We present a widely-tunable, singly-resonant optical parametric oscillator, emitting more than 1 W in the region between 2.7 and 4.2 mu m. Two configurations have been studied in order to improve the frequency stability and the linewidth of the OPO emission. First, we stabilized the signal frequency to a high-finesse Fabry-Perot cavity. Then, we locked both pump and signal frequency to the frequency comb generated by a NIR fs mode-locked fibre laser, linked to the caesium primary standard. With this last configuration we carried out saturation spectroscopy of several transitions belonging to the nu(1) rovibrational band of CH3I, resolving their electronic quadrupole hyperfine structure, and determining the absolute frequency of the hyperfine components with a 50-kHz-uncertainty. An upper limit for the idler linewidth has been estimated as 200 kHz FWHM.
KeyWords: Absolute frequency; Frequency combs; Hyperfine structure; Hyperfines; Optical frequency combs; Primary standards; Quadrupoles; Rovibrational band; Saturation spectroscopy; Signal frequencies; Sub-Doppler molecular spectroscopy; Sub-Doppler spectroscopy; Upper limits, Cesium; Linewidth; Mode-locked fiber lasers; Molecular spectroscopy; Optical parametric oscillators; Pumping (laser); Signal processing, Nonlinear opticDOI: 10.1117/12.960334Citations: 2data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2021-05-09References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here