Silicon Nitride Integrated Electro-Optic Absorption Modulator

Silicon nitride (SiN) is currently the most prominent platform for photonics in the visible and near-IR wavelength bandwidth. However, realizing fast electro-optic (EO) modulators, the key components of any integrated optics platform, remains challenging in SiN. Recently, transparent conductive oxides (TCO) have emerged as a promising platform for photonic integrated circuits. In this work, we take an important step towards combining the advantages of both platforms, reporting for the first-time high-speed indium tin oxide (ITO) electro-optic modulators based on silicon nitride waveguides. We demonstrate a bandwidth higher than 1 GHz, 9.3-um-length active element and an insertion loss of 5.7 dB for a 300 nm-thickness SiN waveguide platform. Simulation results of optimized device designs indicate that further improvements are possible, offering promising opportunities for silicon nitride photonic integrated circuit platform combined with indium oxide based TCO layers.