Grating-Graphene Metamaterial as a Platform for Terahertz Nonlinear Photonics
Jan‐Christoph Deinert, David Alcaraz Iranzo, R. Pérez, Xiaoyu Jia, Hassan A. Hafez, Igor Ilyakov, Nilesh Awari, Min Chen, Mohammed Bawatna, Alexey Ponomaryov, Semyon Germanskiy, Mischa Bonn, Frank H. L. Koppens, Dmitry Turchinovich, Michael Gensch, Sergey Kovalev, Klaas‐Jan Tielrooij
Abstract
, or 21 esu, for a fundamental frequency of 0.7 THz. This nonlinearity is 50 times larger than what we obtain for graphene without grating. Such an enhancement corresponds to a third-harmonic signal with an intensity that is 3 orders of magnitude larger due to the grating. Moreover, we demonstrate a field conversion efficiency for the third harmonic of up to ∼1% using a moderate field strength of ∼30 kV/cm. Finally, we show that harmonics beyond the third are enhanced even more strongly, allowing us to observe signatures of up to the ninth harmonic. Grating-graphene metamaterials thus constitute an outstanding platform for commercially viable, CMOS-compatible, room-temperature, chip-integrated, THz nonlinear conversion applications.