On-chip laser emission from a 2-µm-thick Er³⁺-doped lithium niobate on insulator

We demonstrate a laser emission scheme based on a 2-μm-thick Er³⁺-doped lithium niobate on insulator (Er:LNOI), using a Fabry-Pérot (FP) cavity with Sagnac loop reflectors (SLRs). The experimental results show a multimode laser output at a central wavelength of 1531.5 nm, with a measured on-chip power of 0.36 mW, and slope efficiency of 0.57%. We enhance the laser power of Er:LNOI lasers via a 2-μm-thick lithium niobate on insulator (LNOI) with an enlarged mode area. Additionally, it offers high coupling efficiency with the taper-lensed fiber, making it suitable for light sources in lithium niobate based photonic integrated circuits (PICs) and optical communication systems.