Monolithically integrated MOSFET for controlling silicon optical switch: Is an on-chip transistor capable of driving a thermo-optic phase shifter?

This invited talk will review our work on the monolithic integration of the MOSFET and the thermo-optic (TO) based Mach-Zehnder switch (MZS) using the front-end process on the photonic SOI platform. This MOSFET was capable of driving the TO phase shifter because of its large current capability. By tuning the gate voltage of the MOSFET, the switching state of MZS was successfully controlled. We will also present our work on the robust switch design with the intention to minimize the negative influences on switching performance due to so many MOSFET process steps. For this purpose, we had proposed a new 3dB directional coupler which was more robust to the gap variation than the conventional one. Our monolithic MOSFET is promising in simplifying the driver circuits and in developing on-chip drivers for TO-based silicon photonics devices.