Abstract

We propose and analyze a graphene electromagnetic filter for the terahertz (THz) region. The filter represents a planar square array of graphene elements. A unit cell of the array is formed by two coaxial graphene rings placed on the opposite sides of a thin dielectric substrate. The two electromagnetically coupled rings resonate with dipole plasmonic modes. The rings have slightly different dimensions and consequently different yet close individual resonant frequencies. At a frequency lying between these two resonances, the currents in the two interacting rings have opposite directions. This leads to a suppression of the reflected from the array waves and consequently to a high transmission through the array. For the chemical potential of the graphene ${\mu }_c=0.6\mathrm{eV}$, the calculated quality factor of this resonant mode is $Q=5$ at the frequency $f=0.8\mathrm{THz}$. At this frequency, the reflection coefficient of the array equals $-36\mathrm{dB}$ and the transmission peak which is defined by the graphene losses is $-1.8\mathrm{dB}$. We show that the frequency position of the transmission peak can be varied in a wide range by the graphene chemical potential.

© 2015 Optical Society of America

Planar tunable graphene based low-pass filter in the terahertz band

Amin Ghahremani and Gholamreza Moradi
Appl. Opt. 57(27) 7823-7829 (2018)

Tunable circular polarization selective surfaces for low-THz applications using patterned graphene

Yuezhou Li, Junmin Zhao, Hai Lin, William Milne, and Yang Hao
Opt. Express 23(6) 7227-7236 (2015)

Graphene-based metasurface for a tunable broadband terahertz cross-polarization converter over a wide angle of incidence

Vinit Singh Yadav, Sambit Kumar Ghosh, Somak Bhattacharyya, and Santanu Das
Appl. Opt. 57(29) 8720-8726 (2018)

Planar all-silicon metamaterial for terahertz applications

Sergey L. Prosvirnin, Victor A. Dmitriev, Yeugenii M. Kuleshov, and Vyacheslav V. Khardikov
Appl. Opt. 54(13) 3986-3990 (2015)

Active plasmonic band-stop filters based on graphene metamaterial at THz wavelengths

Zhongchao Wei, Xianping Li, Jianjun Yin, Rong Huang, Yuebo Liu, Wei Wang, Hongzhan Liu, Hongyun Meng, and Ruisheng Liang
Opt. Express 24(13) 14344-14351 (2016)