HOLOGRAPHIC-BASED LEAKY WAVE ANTENNAS AND PHONON-ENHANCED WAVEGUIDES FOR INFRARED APPLICATIONS
Manene, Franklin Muriuki
MetadataShow full item record
This work contributes to critical requirements for antenna-coupled detection applications: 1) large capture cross section with design control of angular response and 2) long propagation lengths of complex signals. Antenna-coupled detectors for infrared applications provide appreciable capture cross sections while delivering signals to sub-wavelength-sized detectors. In this work, leaky-wave antennas are considered for the first time in the infrared spectrum. Design characterization of angular radiation patterns as well as polarization is presented. While leaky-wave antennas hold great promise for enhancing capture cross section, thus narrowing the field of view of the detector, there is a parallel need to preserve coherent signals over long propagation lengths. Infrared electromagnetic fields can couple to phonon-polaritons, the collective oscillation of lattice charges, much like plasmonic coupling that is prominent in the visible spectrum. Hybrid plasmonic optical waveguides have been shown to provide an excellent tradeoff in propagation length and modal confinement. Here we integrate hybrid waveguide designs with silicon carbide, a polar material with a phonon resonance in the long-wave infrared, such that phonon-coupled enhancement, analogous to visible plasmonic effects, are achieved in the infrared.