THz Detectors and Emitters with On-Chip Antenna aligned on Hyper-Hemispherical Silicon Lenses

Abstract

On-chip antennas with radiation towards the substrate are affected by modest coupling performance to a free-space path. (Hyper-)hemispherical silicon lenses can improve the efficiency of quasi-optical emission and detection even at THz frequencies. This approach requires an alignment accuracy in the $\mu\mathrm{m}$-scale at THz frequencies. In this contribution, we report on the benefit of hyper-hemispherical silicon lenses in terms of relaxed alignment accuracy needs. We present the impact of alignment on quasi-optical measurements using indium phosphide resonant-tunneling diodes. The main components of the resulting setups are discussed while the effect of alignment is quantitatively evaluated for both, hemispherical and hyper-hemispherical silicon lenses. Moreover, design rules and concepts for a heterointegrated system are derived on consecutive observations.