Arrayed narrow linewidth erbium-doped waveguide-distributed feedback lasers on an ultra-low-loss silicon-nitride platform

We demonstrate an array of erbium-doped waveguide-distributed feedback lasers on an ultra-low-loss Si3N4 platform. Sidewall gratings providing the lasing feedback are defined in the silicon-nitride layer using 248 nm stepper lithography, while the gain is provided by a reactive co-sputtered erbium-doped aluminum-oxide layer. We observe lasing output over a 12 nm wavelength range (1531–1543 nm) from the array of five separate lasers. Output powers of 8 μW and lasing linewidths of 501 kHz are obtained. Single-mode operation is confirmed, with side-mode suppression ratios over 35 dB for all designs.