Design, Fabrication and Characterization of Capacitively Coupled Silicon-Organic Hybrid Modulators

Silicon-organic hybrid (SOH) modulators [1] offer fast and efficient electro-optic modulation with very small footprints. Traditional SOH modulators suffer from bandwidth limitation due to the higher RC time constant that originates from the resistive coupling of the RF signal. In the current thesis, we propose a new modulator concept establishing a capacitive coupling of the RF signal as opposed to the resistive one in the conventional SOH modulators and hence the name capacitively coupled SOH (CC-SOH) modulator. A high-κ dielectric, BaT iO3 is characterized in optical and in RF regime and later used to design capacitively coupled SOH modulator. The fabicated CCSOH is characterized to have a flat frequency response up to 65 GHz indicating that the 3-dB bandwidth is at least 3 times higher than the SOH modulators.