Nanoantenna for Sensing Applications

Abstract

This thesis studies optical antennas in the IR range. Optical antennas have been studied based on two sections. The first section is studying Silicon-on-Insulator (SOI) grating coupler for coupling the light between an optical fiber and a strip waveguide at operating wavelength 1550 nm based on the available techniques of fabrication. However, the grating coupler has a drawback in the method of coupling as it depends on the incident angle of the light. Therefore, the second section of the thesis solves the problem mentioned above by studying the nanoantenna for coupling and sensing. Nanoantennas can be used for coupling the light, and the incident light, in this case, is perpendicular to the nanoantenna structure. Furthermore, different nanoantenna arrays structures have been studied to be operated at near-infrared (IR) and mid-IR, paving the way to be used as a compact sensor for condensed phase analytes or biomedical enzymes with high efficiency. Finally, this thesis suggests a design of highly doped semiconductor nanoantenna array operating in the Mid-IR, which can be used for sensing condensed phase analytes. These analytes work as biomarkers to detect the enzymes in the blood and work as a biomedical sensor.