Ultra-high-Q substrate-mode coupled resonances in complementary THz metamaterial

Researchers at the Hebrew University of Jerusalem and Shandong Normal University made a terahertz metamaterial with very sharp resonances. It uses two complementary aluminium layers, a disk-hole pattern separated by a thin SU-8 layer, on a quartz substrate. Coupling the metamaterial’s resonance to modes trapped inside the substrate gave experimental Q-factors of up to 750, which the authors describe as a record. Sharp resonances like these are useful for terahertz sensing and filtering. The device was measured with a continuous-wave photomixer system from 0.25 to 1.3 THz. A Purewave wire-grid polarizer was used to measure how the polarization of the test setup changed with frequency.