High-Q terahertz bandpass filters based on coherently interfering metasurface reflections

Opt Lett. 2013 Mar 15;38(6):908-10. doi: 10.1364/OL.38.000908.

Abstract

We present compact and easy-to-realize terahertz bandpass filters with Q values in the order of 500. The filters are based on coherently interfering reflections from two parallel metasurfaces applied to the boundaries of a semiconductor disk. By changing the thickness of the semiconductor disk and the dimensions of the metasurface structures, the filter can be optimized for various terahertz frequencies. Moreover, a precise tuning of the resonance frequency is possible via the temperature of the structure or its angle with respect to the propagation direction.