In‐Plane 1.5 µm Distributed Feedback Lasers Selectively Grown on (001) SOI

Abstract Hetero‐epitaxy for integration of efficient III‐V lasers on silicon can enable wafer‐scale silicon photonic integrated circuits, which can unleash the full advantages of silicon photonics in production on large silicon wafers with low cost, high throughput, and large bandwidth and large‐scale integration. In this work, efficient III‐V distributed feedback (DFB) lasers selectively grown on (001) silicon‐on‐insulator (SOI) wafers are presented. The selective hetero‐epitaxy of sufficiently large areas of III‐V segments allows the demonstration of DFB lasers on the SOI wafer. The fabricated DFB lasers feature a co‐planar configuration with the Si layer, allowing for efficient coupling between III‐V lasers and Si waveguides. The unique III‐V‐on‐insulator structure also provides strong optical confinement for the lasers. Gratings are designed and fabricated with minimal non‐radiative recombination and a simple process with good tolerance. The optically pumped DFB laser has a low lasing threshold of around 17.5 µJ cm −2 , stable single‐mode lasing at 1.5 µm, a side‐mode‐suppression‐ratio of over 35 dB, and a spontaneous emission factor of 0.7. The results here demonstrate a step forward towards wafer‐scale integration with monolithically grown lasers, thus outlining the prospect of fully integrated Si photonics.