Infrared Optical Sensor

Abstract

This thesis study integrated gas sensing in the mid infrared (MIR) range of wavelength for on chip applications. For this purpose a detailed sensitivity analysis of different waveguides in gaseous medium in the MIR have been carried out including both plasmonic and dielectric waveguides in order to determine a high sensitivity and low loss sensor. Then, MIR waveguide platforms have been proposed to serve as interconnects and to build different photonic devices. Finally, two high performance refractive index gas sensors working near the absorption fingerprints of many gases have been proposed. Intensity interrogation method is used as it offers compact and cheap sensors. The first sensor use suspended silicon waveguide and the second uses metal insulator plasmonic waveguide and both are in a Mach-Zehnder Interferometer (MZI) configuration.