Infrared Detection and Waveguiding Using Metasurfaces

Abstract

The goal of this work is to be able to detect thermal radiation in the long-wave and mid-infrared spectrum to a reasonable efficiency. In order to aid this effort, antenna arrays with large collection apertures are coupled with infrared bolometers. This dissertation shows the performance of a series-fed patch type of leaky-wave antenna array coupled to a Nickel bolometer in terms of the angular-frequency scanning abilities of the antenna. The antenna is then made out of electrooptic Graphene in order to be able to dynamically tune the radiation properties of the antenna. A two-dimensional leaky-wave antenna array made from Gold is shown to be able to cover a conical swath of 360degrees in azimuth (ϕ) and 64degrees in elevation (θ). Improving the efficiency of the antenna requires designing the antenna out of a low-loss material. To this effect, hybrid waveguides using phonon polaritons are then explored. The hybrid waveguide performances are benchmarked using the propagation length and field-confinement area (modal area) of the guided wave as figures of merit. A hybrid waveguide is designed using Silicon Carbide and hexagonal Boron Nitride. In the latter case, the unique hyperbolic properties that result in unique hybrid-waveguide modes based on volumetric hyperbolic phonons are explored. Finally, a hybrid slot waveguide is designed using h-BN’s hyperbolic surface phonon polaritons and is shown to have more modal confinement and longer propagation length (lower loss) than the volumetric hyperbolic phonons. This novel hyperbolic hybrid slot waveguide is then coupled into an antenna in order to radiate.