Design and investigation of a novel silicon/ferroelectric hybrid electro-optical microring modulator

A silicon (Si) and lanthanum-doped lead zirconium titanate (PLZT) hybrid microring modulator based on silicon-on-insulator (SOI) platform is designed theoretically and investigated numerically in this paper. The heterogeneous integration of PLZT film with Si material enables the waveguide to acquire both excellent electro-optical property and strong mode confinement capacity. Such hybrid microring modulator (100 μm in radius) has a PLZT rib-loaded cladding and is integrated with optimized tuning electrodes. The simulation results demonstrated that the Si/PLZT hybrid microring modulator could operate at 14 GHz with a relative high modulation efficiency (<0.8 V cm),  which is much better than the other proposed Si/ferroelectric modulators. Meanwhile, under a driving voltage of 20 V, our modulator exhibits an extinction ratio of 32 dB at 1550.22 nm wavelength and a resonant wavelength tunability of 25 pm/V for TE mode. With these outstanding performances, the Si/PLZT hybrid microring modulator holds a great potential as a reliable on-chip device for optical communications and links.