Frequency stability characterization of a quantum cascade laser frequency comb
Authors: Cappelli F., Campo G., Galli I., Giusfredi G., Bartalini S., Mazzotti D., Cancio P., Borri S., Hinkov B., Faist J., De Natale P.
Autors Affiliation: CNR-INO – Istituto Nazionale di Ottica, Largo Enrico Fermi 6, 50125 Firenze FI, Italy & LENS – European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019, Sesto Fiorentino FI, Italy;
Institute for Quantum Electronics, ETH Zurich, 8093, Zurich, Switzerland
Abstract: Optical frequency combs generated by quantum cascade lasers have recently been demonstrated in the mid and far infrared, but a detailed analysis of the possibility of a fine control of the emission to use them for high-resolution spectroscopy and metrology applications is still missing. In this manuscript the attempt of frequency stabilizing a mid-infrared quantum cascade laser comb (QCL-comb) against a metrological mid-infrared intracavity-difference-frequency-generated comb through a single phase-locking chain acting on the driving current is presented. Following a brief derivation, simple relations between the QCL-comb frequency parameters and optical quantities such as the refractive index have been found and used to observe how the locking affects the physics of the system. The conclusion is that the current locking essentially acts on the effective refractive index to reduce the offset fluctuations (common noise), but does not sensitively affect the group refractive index and the mode spacing. Nonetheless, the overall single QCL-comb tooth linewidth is reduced from 500 kHz down to values ranging from 1 to 23 kHz on a 40 ms time scale.
Journal/Review: LASER & PHOTONICS REVIEWS
Volume: 10 (4) Pages from: 623 to: 630
More Information: We thank Gustavo Villares for useful scientific discussions. We gratefully acknowledge funding from ESFRI Roadmap – Extreme Light Infrastructure (ELI) project, Italian Ministry of Foreign Affairs – “Broadcon” Italy-Israel bilateral project, and EU 7th Framework Program, Laserlab-Europe – grant agreement 284464.KeyWords: Infrared devices; Laser mode locking; Locks (fasteners); Optical emission spectroscopy; Refractive index; Semiconductor lasers; Spectroscopic analysis, Effective refractive index; Frequency combs; Group refractive index; High-resolution spectroscopy; Laser stabilization; Mid-infrared quantum cascade; Optical frequency combs; Stability characterizations, Quantum cascade lasersDOI: 10.1002/lpor.201600003Citations: 21data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2020-08-09References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here