A QCL-based metrological-grade source at 6 mu m
Authors: D’Ambrosio D., Borri S., Calonico D., Clivati C., De Natale P., De Pas M., Insero G., Levi F., Verde M., Santambrogio G.
Autors Affiliation: CNR, INO, Via Nello Carrara 1, I-50019 Florence, Italy; LENS, European Lab Nonlinear Spect, Via Nello Carrara 1, I-50019 Florence, Italy; Ist Nazl Ric Metrol, INRIM, Str Cacce 91, I-10135 Turin, Italy; Ist Nazl Fis Nucl, Sez Firenze, Via G Sansone 1, I-50019 Florence, Italy; Fritz Haber Inst Max Planck Gesell, Faradayweg 4-6, D-14195 Berlin, Germany; JRC, European Commiss, Karlsruhe, Germany
Abstract: In view of high-precision molecular spectroscopy in the infrared, we realized a narrow-linewidth laser source at 5.8 mu m traceable to the second in the International System of Units by mixing two near-infrared lasers in an orientation-patterned GaP crystal. The generated radiation is traceable to a Cs fountain through an optical fiber-delivered carrier; its estimated linewidth is 2.3 kHz at 1 s integration time. A quantum cascade laser emitting at the same wavelength is used to boost the power of the mid-IR radiation up to few tens of mW. Thanks to a phase-locking loop, about 70% of the quantum cascade laser output power is within the linewidth of the difference-frequency radiation. This apparatus is used for absolute molecular spectroscopy in a region, above 5 mu m, where high-precision traceability and reliable operation are still challenging. In this paper, we provide the basic information to implement a powerful and metrological grade source in the mid-infrared for precision measurements.
Journal/Review: APPLIED PHYSICS B-LASERS AND OPTICS
Volume: 126 (3) Pages from: 41-1 to: 41-8
KeyWords: QUANTUM CASCADE LASER; OPTICAL FREQUENCY; PRECISION SPECTROSCOPY; STABILIZATION; RADIOCARBON; LINEWIDTH; LIMIT; TIME; LINKDOI: 10.1007/s00340-020-7388-4Connecting to view paper tab on IsiWeb: Click here