title: Frequency-comb-referenced quantum-cascade laser at 4.4 microm.
abstract: We report what we believe to be the first absolute frequency measurement performed using a quantum-cascade laser (QCL) referenced to an optical frequency comb synthesizer (OFCS). A QCL at 4.43 microm has been used for producing near-infrared radiation at 858 nm by means of sum-frequency generation with a Nd:YAG source in a periodically poled lithium niobate nonlinear crystal. The absolute frequency of the QCL source has been measured by detecting the beat note between the sum frequency and a diode laser at the same wavelength, while both the Nd:YAG and the diode laser were referenced to the OFCS. Doppler-broadened line profiles of (13)CO(2) molecular transitions have been recorded with such an absolute frequency reference.
authors: CNR-Istituto Nazionale di Ottica Applicata, Firenze FI, Italy.
authors: S
authors: S
authors: Bartalini
authors: P
authors: P
authors: Cancio
authors: G
authors: G
authors: Giusfredi
authors: D
authors: D
authors: Mazzotti
authors: P
authors: P
authors: De Natale
authors: S
authors: S
authors: Borri
authors: I
authors: I
authors: Galli
authors: T
authors: T
authors: Leveque
authors: L
authors: L
authors: Gianfrani