Thermo-optic modulation of plasmonic bandgap on metallic photonic crystal slab

We demonstrate active control of plasmonic bandgap on a metallic photonic crystal slab using thermo-optic effects. The Au grating, which is milled by focused-ion beam on a glass substrate, is designed to exhibit an extraordinary optical transmission and a sharp transitional edge for high modulation efficiency. Only a moderate refractive index modulation of Δn = 0.0043 is required to obtain more than 60% modulation depth with surface-normal optical coupling.