Date of Award
Master of Science (MS)
Electrical and Computer Engineering (Holcomb Dept. of)
Judson D Ryckman
William R Harrell
Guided wave-optics is an emergent platform for label free optical biosensing. However, device sensitivity toward surface-attached biomolecules is directly restricted because of only evanescent interaction and low modal overlap with the active sensing region. In this work, we demonstrate a mesoporous silicon waveguide design created via a novel inverse processing technique that overcomes the limitations imposed by evanescent field sensing by achieving maximal transverse confinement factor in the active sensing region. Our sensor can also maintain this confinement factor and sensitivity across a large dimensional variation while preserving single-mode operation. Our devices are characterized in a Fabry-Perot interferometer configuration and the ultra-high sensitivity to small molecule adlayers is shown. We also discover dispersion to be a promising degree of freedom for exceeding the bulk sensitivity limits predicted by non-dispersive and isotropic effective medium theory.
Talukdar, Tahmid Hassan, "Porous Silicon Photonics at Unity Confinement Factors for Surface Adlayer Biosensing" (2019). All Theses. 3216.