Abstract-Selective excitation of resonances in gammadion metamaterials for terahertz wave manipulation

DaCheng WANG,  Qin HUANG,  ChengWei QIU,  MingHui HONG,

http://engine.scichina.com/publisher/scp/journal/SCPMA/58/8/10.1007/s11433-015-5674-7?slug=fulltext

A gammadion terahertz (THz) metamaterial embedded with a pair of splits is experimentally investigated. By introducing the pair of splits at different arms, the transmitted amplitude at the resonance frequency can be manipulated from 61% to 24%. Broadband static resonance tunability from 1.11 to 1.51 THz is also demonstrated via varying the relative split positions at certain arms. The amplitude change and static resonance tunability are attributed to the introduced split pairs, which enable selective excitation of different resonance modes in the gammadion metamaterials. This work promises a new approach to design THz functional devices.

Abstract-Coupling effect of spiral-shaped terahertz metamaterials for tunable electromagnetic response

Dacheng Wang, Chengwei Qiu, Minghui Hong
http://link.springer.com/article/10.1007/s00339-013-7928-4
Coupling effect in spiral-shaped metamaterials composed of four half rings at different sizes is investigated to achieve tunability in THz range. This novel spiral-shaped structure was fabricated on flexible substrate with laser micro-lens array (MLA) lithography and measured by THz time domain spectroscopy (THz-TDS). The experimental results suggest that mutual capacitance and inductance coupling in the spiral-shaped structure would result in frequency shifts of the four resonances. The observed shifting trends of the four resonant frequencies are in good agreement with simulation and are further explained by the electric field distribution. By varying the gap sizes among the half rings, four resonant frequencies can be tuned flexibly. Such a spiral-shaped design has potential applications in multi-band tunable THz MEMS devices.