Silicon nitride (SiN) is currently the most prominent platform for photonics in the visible and near-IR wavelength bandwidth. However, realizing fast electro-optic modulators, the key components of any integrated optics platform remain challenging in SiN. Recently, transparent conductive oxides have emerged as a promising platform for photonic integrated circuits. In this work, we take an important step toward combining the advantages of both platforms, reporting for the high-speed indium tin oxide electro-optic modulators based on silicon nitride waveguides. We demonstrate a bandwidth higher than 1 GHz, 9.3-μm-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 layers.
Lotkov et al. (Mon,) studied this question.