Theodosi, Anna and Otoo, Isaac Appiah and Koulouklidis, Anastasios D. and Matthaiakakis, Nikolaos and Kakarantzas, George and Mustonen, Petri and Lipsanen, Harri and Fedorov, Georgy and Liontos, Ioannis and Tzortzakis, Stelios and Kuzhir, Polina and Kafesaki, Maria and Tsilipakos, Odysseas (2025) Graphene Nanosheet-Gold Nanopatch Metasurfaces for Nonlinear Response at THz Frequencies. ACS APPLIED NANO MATERIALS, 8 (51). pp. 24473-24479. ISSN 2574-0970
Full text not available from this repository. (Request a copy)Abstract
Graphene's exceptional nonlinear optical properties combined with resonant photonic structures offer a promising pathway for efficient nonlinear applications at terahertz (THz) frequencies. In this work, we propose and demonstrate a fabrication-friendly hybrid nonlinear metasurface composed of gold patches integrated with uniform graphene, circumventing the need for complex graphene patterning. The structure supports strong localized resonances that enhance nonlinear interactions. By exploiting resonant enhancement at both the fundamental and third harmonic frequencies, we predict via simulations third-harmonic generation efficiencies as high as -15 dB (3.2%) under continuous-wave excitation at modest intensities (0.1 MW/cm2). The metasurface is fabricated via electron-beam lithography and experimentally characterized under pulsed excitation using THz time-domain spectroscopy. The broadband excitation spectrum prevents unambiguous isolation of a third-harmonic signal; however, we experimentally observe pronounced nonlinear frequency shifts up to 0.5 THz (12.5% fractional change), driven by self-phase modulation, consistent with simulation results. Our findings highlight the potential of tailored graphene-based metasurfaces for efficient nonlinear THz photonic devices.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | third harmonic generation; nonlinear frequency shift; self-phase modulation; doubly resonant enhancement; metamaterials; nonlinear optics |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Theroretical Physics Regensburg Center for UltrafastNanoscopy (RUN) |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 31 Mar 2026 04:45 |
| Last Modified: | 31 Mar 2026 04:45 |
| URI: | https://pred.uni-regensburg.de/id/eprint/66772 |
Actions (login required)
 |
View Item |
