@inproceedings{d5a6410c785a4088bd51e526c4235c60,
title = "Narrow-linewidth ultra-broadband terahertz sources based on difference-frequency generation in mid-infrared quantum cascade lasers",
abstract = "We discuss novel approaches to improve the tuning bandwidth and power output of terahertz (THz) sources based on difference-frequency generation (DFG) in mid-infrared quantum cascade lasers (QCLs). Using a double Littrow external-cavity system, we experimentally demonstrate that both doubly-resonant terms and optical rectification terms in the expression for the intersubband optical nonlinearity contribute to THz generation in DFG-QCLs and report THz DFG-QCLs with the optimized optical rectification terms. We also demonstrate a hybrid DFG-QCL device on silicon that enables significant improvement on THz out-coupling efficiency and results in more than 5 times higher THz output power compared to that of a reference device on its native semi-insulating InP substrate. Finally, we report for the first time the THz emission linewidth of a free-running continuous-wave THz DFG-QCL.",
keywords = "Difference-frequency generation, Linewidth, Nonlinear optical rectification, Quantum cascade lasers, Terahertz",
author = "Seungyong Jung and Yifan Jiang and Kim, {Jae Hyun} and Luigi Consolino and Saverio Bartalini and {De Natale}, Paolo and Miriam Vitello and Kazuue Fujita and Masahiro Hitaka and Akio Ito and Jeremy Kirch and Dan Botez and Frederic Demmerle and Gerhard Boehm and Amann, {Markus Christian} and Belkin, {Mikhail A.}",
note = "Publisher Copyright: {\textcopyright} 2017 SPIE.; Novel In-Plane Semiconductor Lasers XVI 2017 ; Conference date: 30-01-2017 Through 02-02-2017",
year = "2017",
doi = "10.1117/12.2256099",
language = "English",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Smowton, {Peter M.} and Belyanin, {Alexey A.}",
booktitle = "Novel In-Plane Semiconductor Lasers XVI",
}