Plasmonic Terahertz Nonlinearity in Graphene Disks

Advanced Photonics Research

Howard Dennis Drew¹  Kevin M. Daniels²  Gagan Kumar³  Dmitry Turchinovich⁴  Hassan A. Hafez⁴  Jeong Woo Han⁵  Sebastian Matschy⁵  Martin Mittendorff⁵  Angelika Seidl⁶  Stephan Winnerl⁶  Jayaprakash Poojali⁷  Matthew L. Chin⁷  Thomas E. Murphy⁷  Rachael L. Myers-Ward⁸  Matthew T. Dejarld⁸ 

[1] Center for Nanophysics and Advanced Materials University of Maryland College Park MD 20740 USA;Department of Electrical and Computer Engineering University of Maryland College Park MD 20740 USA;Department of Physics, Guwahati Indian Institute of Technology Guwahati Guwahati Assam 781039 India;Fakultät für Physik Universität Bielefeld 33615 Bielefeld Germany;Fakultät für Physik Universität Duisburg-Essen 47057 Duisburg Germany;Institut für Ionenstrahlphysik und Materialforschung Helmholtz-Zentrum Dresden-Rossendorf 01328 Dresden Germany;Institute for Research in Electronics and Applied Physics University of Maryland College Park MD 20740 USA;U.S. Naval Research Laboratory Washington DC 20375 USA;

关键词: carrier dynamics;    graphene;    plasmonic nonlinearities;    terahertz;    thermal nonlinearities;   

DOI  :  10.1002/adpr.202100218

来源: DOAJ

【 摘 要 】

The discovery of graphene and its unique optical and electronic properties has triggered intense developments in a vast number of optoelectronic applications, especially in spectral regions that are not easily accessible with conventional semiconductors. Particularly in the THz regime, where the free‐carrier interaction with low‐energetic photons usually dominates, detectors and modulators based on graphene often feature an improved response time. Nevertheless, the light−matter interaction suffers from the small interaction volume. One way to enhance the efficiency of such devices at elevated frequencies is by patterning graphene into plasmonic structures like disks. In addition to the increased linear absorption, the plasmon resonance also creates a strong, surface‐localized field that enhances the nonlinear optical response. While experimental studies so far have focused on hot carrier effects, theoretical studies also suggest an increase in the nonlinearity beyond thermal effects. Herein, polarization‐dependent pump‐probe measurements on graphene disks that disentangle the contributions of thermal and plasmonic nonlinearity are presented. An increase in the pump‐induced transmission is observed when pump and probe radiation are copolarized. To further elucidate the interplay of thermal and plasmonic effects, a model that supports the origin of the polarization‐dependent enhancement of the observed THz nonlinearities is developed.

【 授权许可】

Unknown