LABEL-FREE REFRACTIVE INDEX SENSING WITH FREE-SPACE COUPLED PHOTONIC CRYSTAL SLABS

Abstract

Label-free optical resonance sensors can detect small changes of refractive index (RI), which could be used for biochemical molecular detection, drug screening or gas detection. One of the most critical parameters in these sensors is the sensor detection limit (DL). Reducing DL can be achieved by increasing the resonance quality factors (Q) and the spectral sensitivity (S). Another critical research challenge in these sensors is the sensing specificity.

In this thesis, based on Fano resonance principle in two-dimensional photonic crystal slabs (PCS) and the integration with gas separation columns, we investigated various free-space coupled on-chip optical resonance sensors for both liquid sensing and gas sensing/separation.