Intrinsic linewidth of quantum cascade laser frequency combs
Authors: Cappelli F., Villares G., Riedi S., Faist J.
Autors Affiliation: Institute for Quantum Electronics, ETH Zurich, Zürich, 8093, Switzerland; CNR-INO, Istituto Nazionale di Ottica, Largo Enrico Fermi 6, Firenze, FI 50125, Italy; LENS, European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, Sesto Fiorentino, FI 50019, Italy
Abstract: Optical frequency combs based on quantum cascade lasers have recently been demonstrated in the mid- and far-infrared spectral regions, opening the possibility for broadband, compact spectrometers. The successful operation of these systems will depend on understanding the frequency noise of these lasers, whose mode-locking dynamics leads to an almost constant optical power rather than pulse generation. We demonstrate that the four-wave mixing process— responsible for comb formation—effectively correlates the quantum frequency noise of the individual comb modes. The plateau observed in the high-frequency portion of the noise spectrum is attributed to the quantum noise limit. This result proves that four-wave mixing introduces no additional frequency noise, showing that quantum cascade laser combs are well suited for high-resolution spectroscopy applications.
Volume: 2 (10) Pages from: 836 to: 840
KeyWords: Four wave mixing; Infrared lasers; Laser mode locking; Locks (fasteners); Quantum cascade lasers; Quantum noise; Spectrometers; Spectroscopic analysis, Four-wave-mixing process; High frequency HF; High-resolution spectroscopy; Infrared and far-infrared lasers; Lasers and laser optics; Optical frequency combs; Quantum cascades; Quantum noise limit, Semiconductor lasersDOI: 10.1364/OPTICA.2.000836Citations: 31data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2023-02-05References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here