Joint Annual Meeting of SPS and ÖPG 2019

【178】A polarization-rotating Vivaldi antenna for improved far-field patterns of broadband terahertz quantum cascade lasers

28 Aug 2019, 19:00

1h 30m

Lichthof

Poster Condensed Matter Physics (KOND) Poster Session

Speaker

Mr Urban Senica (ETH Zurich)

Description

Terahertz quantum cascade lasers based on double metal waveguides are compact sources of terahertz radiation with excellent properties in terms of covering a large bandwidth and exhibiting low waveguide dispersion. However, as the optical mode is confined to subwavelength dimensions, the emitted radiation produces a highly divergent far-field pattern. We designed and fabricated an antipodal Vivaldi antenna which adiabatically expands the optical mode while rotating its polarization from vertical towards horizontal polarization. Numerical simulations predict a single-lobed far-field pattern with a beam width of less than 20°, spanning over two octaves in frequency (1.5-4.5 THz). Far-field measurements agree well with simulations.