Broadband Light Absorption Using Ultrathin Plasmonic Super Absorbers

Abstract

Nanophotonics is an emerging technology that involves the interaction of light with small structures. One of the significant fields of nanophotonics is Plasmonics and metamaterials. The field of plasmonics has emerged as an interesting area for the fundamental studies, with important application possibilities in miniaturized photonics components. Plasmonic structures allow for the control of fundamental optical processes such as absorption, emission and refraction at the nanoscale due to the large field enhancement of localized or propagating surface plasmon resonances on the surface of the substrate. This thesis is focused on fabricating such a device which yields broadband light absorption over the visible spectrum (400-700 nm) as well as in the infrared spectrum (750 nm -1000 nm). The design is based on an ultrathin plasmonic super absorber consisting of a metal-insulator-metal stack with a nanostructured top silver film composed of circular holes of fishnet type structure for the visible spectrum and periodic elliptical holes of fishnet type structure for the infrared spectrum. Proposed broadband absorbers will open new device possibilities in thermal sensors, photovoltaic, optoelectronic devices, and also to conceal photo detectorsunpublishednot peer reviewedU of I OnlyUndergraduate senior thesis not recommended for open acces