Broadband Terahertz Hybrid Twisted Horn Antenna for the Electric Field Polarization Manipulation of Spintronic Terahertz Radiation Emitters

With wireless communication frequencies steadily approaching the terahertz (THz) band, research into devices for on-chip wireless THz communication systems is at its zenith. In this work, we utilize two-photon lithography techniques to fabricate a continuous twisted waveguide exhibiting at least 90% electric field polarization rotation efficiency from 1.0 to 3.0 THz, as well as a hybrid twisted pyramidal horn antenna capable of both polarization rotation and beaming, with a 10 dB bandwidth of 1.7 THz (from 0.3 to 2.0 THz), providing a maximum gain of 12 dB at 1.1 THz, and having a wideband operating region with 90–100% polarization rotation efficiency from 0.3 to 1.75 THz. Due to their versatility and their innate ability to perform multiple functions such as guiding and beaming THz radiation from spintronic THz radiation emitters while manipulating their electric field polarization, we envision such structures to be used for on-chip applications similar to their microwave counterparts, eliminating the need for multiple elements such as antennas, waveguides, and polarizers on dense chips where device footprint comes at a premium.