Enhanced directive terahertz radiation emission from a horn antenna-coupled W/Fe/Pt spintronic film stack

Abstract

We demonstrate enhanced directive terahertz (THz) radiation emission from a horn-antenna coupled spintronic THz radiation emitter without the use of additional lenses. The waveguide-fed horn antenna is fabricated using 3D lithography and is coupled directly to the THz-emitting film serving to direct the highly divergent THz radiation emitted by the spintronic THz radiation emitter. The antenna-coupled emitter provides a 19.6dB increase in the measured signal power at 1.5THz compared to a bare emitter. Finite-difference time-domain simulations are conducted to gain insight into the behavior of the antenna at different frequencies, providing results that match those observed experimentally. Our device is well suited for platforms where footprint size is a constraint and can be modified to act as a directive bandpass filter.