Integration of cascaded electro-optic and nonlinear processes on a lithium niobate on insulator chip.

Cascading of the electro-optic (EO) effect and nonlinear wave mixing can provide a way to manipulate photonic conversion in an electrically controllable manner. Here we experimentally demonstrate simultaneous transverse EO coupling and second-harmonic generation (SHG) in a periodically poled lithium niobate on insulator ridge waveguide. With tight light confinement, large EO, and nonlinear coefficients in the LNOI waveguide, the integrated device features a low-voltage fast-speed response for EO coupling and efficient conversion for SHG. The proposed scheme holds promise in realizing electrically controllable on-chip nonlinear devices.