Engineered second-order nonlinearity in silicon nitride

The lack of a bulk second-order nonlinearity ( χ (2) ) in silicon nitride (Si 3 N 4 keeps this low-loss, CMOS-compatible platform from key active functions such as Pockels electro-optic (EO) modulation and efficient second harmonic generation (SHG). We demonstrate successful induction Si through electrical poling with an externally-applied field to align the Si-N bonds. This alignment breaks centrosymmetry , enables . sample is heated over 500°C facilitate poling. comparison between EO responses poled non-poled measured using micro-ring modulator, shows at least 25X enhancement r 33 component. maximum we obtain 0.30pm/V. observe remarkable improvement speed GHz 15 (3 dB bandwidth) after poling, which confirms nature response induced by work paves way for high-speed on platform.