High Power on-chip Integrated Laser

The lack of high power integrated lasers have been limiting silicon photonics. Despite much progress made in chip-scale laser integration, power remains below the level required for key applications. The main inhibiting factor for high power is the low energy efficiency at high pumping currents, dictated by the small size of the active device. Here we break this power limitation by demonstrating a platform that relies on the coupling of a broad-area multimode gain to a silicon-nitride feedback chip, which acts as an external cavity. The feedback provided by the silicon-nitride chip is routed through a ring resonator and a single-mode filter, thus causing the otherwise 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 high-performance metrics while maintaining a small footprint of 3 mm^2.