  The commercialization of lithium niobate on insulator (LNOI) wafer has
sparked significant on-chip photonic integration application due to its
remarkable photonic, photoacoustic, electro-optic and piezoelectric nature. A
variety of on-chip LNOI-based optical devices with high performance has been
realized in recent years. Here we developed 1 mol\% erbium-doped LN crystal and
its LNOI wafer, and fabricated an erbium-doped LNOI microdisk with high quality
($ \sim $ 1.05$\times 10^{^5}$ ). C-band laser emission with $ \sim $1530 nm
and $ \sim $1560 nm from the high-Q erbium-doped LNOI microdisk was
demonstrated both with 974 nm and 1460 nm pumping, and the latter has better
thermal stability. This microlaser would play an important role in the photonic
integrated circuits of lithium niobate platform.
