Evolution of rod antennas for integrated terahertz photonics

Abstract

Integrated terahertz photonics has emerged as a viable option for routing and processing terahertz signals with high efficiency and broad bandwidth. This can be implemented by using photonic crystal waveguides entirely made of a float-zone intrinsic silicon slab that has exceptionally low loss for terahertz waves. A challenge presented here is to couple guided waves in this integrated platform with free-space waves. It is imperative that the coupling antennas must have low loss, high bandwidth, and high gain, and be integrated as a part of the platform. Here we present an evolution of antenna designs from a single dielectric rod to a rod array that can satisfy all these requirements. All these antennas are integrated onto the same silicon photonic crystal slab used for waveguiding.