Multipolar silicon-based resonant meta-surface for electro-optical modulation and sensing

A multipolar silicon-based resonant meta-surface scheme is proposed and numerically presented via intercalating oblique slits into the silicon patches, leading to an ultra-sharp resonant spectrum via the excitation of electric and magnetic quadrupoles and their hybridization coupling. High-performance electro-optical modulator is demonstrated, showing a spectrally shifted modulation sensitivity up to 1.546 nm/V. Moreover, novel, to the best of our knowledge, optical sensing for ion solution concentration with the detection limitation down to 5.15 × 10^-3 is demonstrated as another application. These findings provide an impressive strategy for resonant silicon-based nano-photonics and opto-electronic devices.