High power chip-scale laser

The lack of high-power integrated lasers has been limiting silicon photonics. Despite much progress in chip-scale laser integration, power output remains below levels required for key applications due to low energy efficiency at high pumping currents. Here we break this power limitation by coupling a broad-area multimode gain chip to a silicon-nitride ring resonator and single-mode filter. The resulting optical feedback causes the multimode-gain chip to concentrate its power into a single highly coherent mode. Our device produces more than 150 mW of power and 400 kHz linewidth. We achieve these metrics while maintaining a small footprint of 3 mm 2 .