Frequency-comb-referenced quantum-cascade laser at 4.4 microm.
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.
Bartalini
S
S
CNR-Istituto Nazionale di Ottica Applicata, Firenze FI, Italy.
Cancio
P
P
Giusfredi
G
G
Mazzotti
D
D
De Natale
P
P
Borri
S
S
Galli
I
I
Leveque
T
T
Gianfrani
L
L