摘要
Nonlinear optical processes play vital roles in the field of optics. Among various nonlinear photonic material platforms, lithium niobate (LN) is a particularly attractive and versatile one owing to its superiorχ^((2))nonlinearity and wide transparency window. The recent development of the lithium-niobate-on-insulator (LNOI) platform has further allowed these processes to be realized in an efficient and compact manner thanks to the strong light confinement in the sub-micron thin LN device layer [1-3].