Near-zero dispersion photonic crystal slab waveguide using ring-shape-holes and optofluidic infiltration

A photonic crystal slab waveguide is presented which utilizes the benefits of both ring-shape-holes (RSHs) and optofluidic infiltration approaches. A tailorable bandwidth is achieved, while the group velocity dispersion is kept near zero adjusting the inner radii of the RSHs (r from 0.179a to 0.221a) and using different refractive indices of optofluids (nf from 1.3 to 2.1). Results of numerical simulations using three-dimensional plane wave expansion method yield slow light with different group indices (ng from 25.5 to 122) and bandwidths (from 15 nm to 1.7 nm) for the different r and nf. Normalized delay-bandwidth product is also calculated in the range of 0.25 to 0.135. Fabrication error tolerance is 0.23% for ±2 nm error in r which means that the dependence of the proposed structure to the fabrication accuracy is negligible.