Dual-color upconversion luminescence emission from Er:LiNbO3 on-chip ridge waveguides

Dual-color upconversion luminescence of Er3+-doped (0.1% mol) lithium-niobate-on-insulator (Er:LNOI) on-chip ridge waveguides is observed under the excitation of a continuous-wave 980-nm semiconductor laser, emitting both blue (at 450 nm) and green (at 528.3 nm) fluorescence emissions. The on-chip waveguides, with a propagation loss of around 3 dB/cm at 1550 nm, are fabricated by diamond blade dicing technique. The experimentally observed waveguiding modal profiles are in fairly good agreement with simulation results, indicating good quality of the fabricated waveguides. We believe this work will benefit the development of LiNbO3-based integrated photonics.