Wide angle terahertz sensing with a cross-dipole frequency selective surface

Abstract

In this work, a terahertz sensor based on a cross dipole frequency selective surface is analyzed and experimentally tested. The sensing structure is optimized for operation at the fundamental band- stop resonance near 0.7THz and characterized under normal and oblique incidence. The sensing performance as a function of the incidence angle and the wave polarization is evaluated with good agreement between simulations and measurements. It is shown that a figure of merit for the pro- posed sensor can be enhanced from 0.2 up to 0.6 due to switching from normal to oblique excita- tion, which yields the maximum performance for TM polarization at the incidence angle of 70º. The presented results demonstrate a wide angle operation regime in THz sensing that opens up an alternative approach in improving capabilities of sensing devices.