1. Investigation of Novel materials for Grating based Infrared Surface Plasmon Resonance (SPR) biosensor; Funded by Air Force Office of Scientific Research (AFOSR) USA.
Conductors with infrared plasma frequencies are potentially useful hosts of surface plasmon polaritons (SPP) with sub-wavelength mode confinement for sensing applications. A challenge is to identify such a conductor that also have sharp SPP excitation resonances and the capability to be functionalized for biosensor applications that operates deep into the infrared (3-11 µm) wavelengths. In this project, I studied experimental and theoretical investigations of IR SPP grating coupling on doped silicon semimetals such as antimony, bismuth and conducting polymer such as polyaniline.
QCLs tend to fail at optical power densities on the order of 10MW/cm2, which roughly corresponds to total power level of 5W for narrow-ridge (10µm-wide) devices. In this project a systematic basic research is carried out on catastrophic optical damage (COD) for high power quantum cascade lasers (QCLs) to identify positive feedback loops responsible for the thermal runaway in high power QCLs. The goal of this project is to develop a COD model capable of accurately predicting the damage threshold based on thermal and optical data and analyzing defect formation and defect diffusion near the output facet on a long time-scale to quantify the impact of the defect formation and propagation on high power QCL reliability.
