Hybrid Si-LiNbO 3 microring electro-optically tunable resonators for active photonic devices

Hybrid Si-LiNbO3 electro-optic tunable ring resonators have been proposed and demonstrated as a path to achieving ultracompact and high-speed electro-optic devices. Free standing single crystal LiNbO3 microplatelets (∼mm long and ∼1 μm thick) were obtained from a z-cut LiNbO3 substrate by ion implantation and thermal treatment. The platelets were transferred and thermally bonded on top of Si resonators that were fabricated in a Si-on-insulator platform by a 0.18 μm standard complementary metal-oxide-semiconductor process. For the hybrid microring resonator, a free spectral range of 16.5 nm, a finesse F of ∼1.67×102, a Q-factor of ∼1.68×104, and an effective r coefficient of ∼1.7 pm/V were achieved for the TE mode. These values are in good agreement with the calculated results.