Integrated distributed Bragg reflector lasers in silicon nitride waveguides coated with erbium-doped tellurite

In this work, we show on-chip distributed Bragg reflector lasers in 200-nm-thick silicon nitride waveguides coated with erbium-doped tellurium dioxide. The devices consist of asymmetrical cavities defined by sidewall corrugations patterned directly on 2.2-cm-long silicon nitride waveguides. The lasers operate within the C-band (1530-1565 nm) with highly directional output and efficiencies up to 0.36% and lasing threshold as low as 13 mW when pumped with 1470 nm light.