Terahertz radiation in graphene hyperbolic medium excited by an electric dipole

Authors

Xiaodong Feng, University of Electronic Science and Technology of China, Cooperative Innovation Centre of Terahertz Science
Sen Gong, University of Electronic Science and Technology of China, Cooperative Innovation Centre of Terahertz Science
Renbin Zhong, University of Electronic Science and Technology of China, Cooperative Innovation Centre of Terahertz Science
Tao Zhao, University of Electronic Science and Technology of China, Cooperative Innovation Centre of Terahertz Science
Min Hu, University of Electronic Science and Technology of China, Cooperative Innovation Centre of Terahertz Science
C Zhang, University of Wollongong, Cooperative Innovation Centre of Terahertz ScienceFollow
Shenggang Liu, University of Electronic Science and Technology of China, Cooperative Innovation Centre of Terahertz Science

RIS ID

123242

Publication Details

Feng, X., Gong, S., Zhong, R., Zhao, T., Hu, M., Zhang, C. & Liu, S. (2018). Terahertz radiation in graphene hyperbolic medium excited by an electric dipole. Optics Letters, 43 (5), 1187-1190.

Abstract

In this Letter, the enhanced and directional radiation in a wide terahertz (THz) frequency range in a graphene hyperbolic medium excited by an electric dipole is presented. The numerical simulations and theoretical analyses indicate that the enhanced radiation comes from the strong surface plasmon couplings in the graphene hyperbolic medium, consisting of alternative graphene and dielectric substrate layers. The simulation results also show that the peak power flow of the enhanced THz radiation in the graphene hyperbolic medium is dramatically enhanced by more than 1 order of magnitude over that in a general medium within a certain distance from the dipole, and the electromagnetic fields are strongly concentrated in a narrow angle. Also, the radiation fields can be manipulated, and the fields' angular distributions can be tuned by adjusting the dielectric permittivity and thickness of the substrates, and the chemical potential of graphene. Accordingly, it provides a good opportunity for developing miniature, integratable, high-power-density, and tunable radiation sources in the THz band at room temperature.