Enhancement of Refractive Index Sensitivity in Photonic Crystal Waveguide-Based Sensors by Selective Infiltration

We present a liquid refractive index sensor based on a photonic crystal waveguide slab structure.Sensing mechanism employed in this study is based on the shift in cut-o wavelength as the lattice holes are selectively inltrated.Three-dimensional plane-wave expansion and nite-dierence time-domain methods are used to determine the band structure and transmission spectra, respectively.First, the sensitivity of the device is analyzed for the structure where only the rst rows of holes adjacent to the line-defect are inltrated.In addition, this analysis is repeated for a range of hole diameters.Second, the eects of inltrated holes which are placed in the line-defect are investigated.As these inltrated central holes are introduced, the proposed device exhibits 5.3 times improved sensitivity.