Kuyken Bart, Ideguchi Takuro, Holzner Simon, Yan Ming, Hänsch Theodor W, Van Campenhout Joris, Verheyen Peter, Coen Stéphane, Leo Francois, Baets Roel, Roelkens Gunther, Picqué Nathalie
1] Photonics Research Group, Department of Information Technology, Ghent University-imec, Sint-Pietersnieuwstraat 41, 9000 Ghent, Belgium [2] Center for Nano- and Biophotonics (NB-Photonics), Ghent University, 9000 Ghent, Belgium.
Max Planck Institut für Quantenoptik, Hans-Kopfermannstrasse 1, 85748 Garching, Germany.
Nat Commun. 2015 Feb 20;6:6310. doi: 10.1038/ncomms7310.
Laser frequency combs, sources with a spectrum consisting of hundred thousands evenly spaced narrow lines, have an exhilarating potential for new approaches to molecular spectroscopy and sensing in the mid-infrared region. The generation of such broadband coherent sources is presently under active exploration. Technical challenges have slowed down such developments. Identifying a versatile highly nonlinear medium for significantly broadening a mid-infrared comb spectrum remains challenging. Here we take a different approach to spectral broadening of mid-infrared frequency combs and investigate CMOS-compatible highly nonlinear dispersion-engineered silicon nanophotonic waveguides on a silicon-on-insulator chip. We record octave-spanning (1,500-3,300 nm) spectra with a coupled input pulse energy as low as 16 pJ. We demonstrate phase-coherent comb spectra broadened on a room-temperature-operating CMOS-compatible chip.
激光频率梳是一种光谱由数十万条均匀间隔的窄线组成的光源，在中红外区域的分子光谱学和传感新方法方面具有令人振奋的潜力。目前正在积极探索此类宽带相干光源的产生。技术挑战减缓了此类发展。识别一种能显著拓宽中红外频率梳光谱的通用型高非线性介质仍然具有挑战性。在此，我们采用一种不同的方法来实现中红外频率梳的光谱展宽，并研究绝缘体上硅芯片上与CMOS兼容的、经过高非线性色散工程设计的硅基纳米光子波导。我们以低至16 pJ的耦合输入脉冲能量记录了倍频程跨度（1500 - 3300 nm）的光谱。我们展示了在室温下工作的与CMOS兼容的芯片上实现的相位相干梳状光谱展宽。
