Tunable Terahertz Bessel-Beam Launchers

Bessel-beam launchers are planar devices capable of focusing electromagnetic energy in their radiative near-field region in the form of Bessel beams. Bessel-beam launchers are typically designed to have certain static beam features over a given operating bandwidth in the microwave/millimeter-wave range. Here, taking cues from some recent advancements in the field, we propose innovative architectures capable of generating Bessel beams at terahertz frequencies and featuring a dynamic control of the cover distance. The ideas outlined in this Vision are expected to pave the way for the realization of the first tunable terahertz Bessel-beam launchers.