Lasing in a Hybrid Rare-Earth Silicon Microdisk

Silicon photonics is an ideal platform for low-cost, energy-efficient, and high-performance optical microsystems. However, because silicon is an inefficient light emitting material, the development of simple, inexpensive, and scalable monolithic amplifiers and light sources has been a significant challenge. Here, optical gain and lasing in an ultra-compact hybrid rare-earth silicon microdisk resonator are reported. The microdisk design is straightforward and compatible with the fabrication steps and device dimensions available in all silicon photonics foundries, while the thulium-doped tellurite gain medium is added in a low-temperature single-step sputter deposition. This approach allows for low-cost and high-volume wafer-scale manufacturing and co-integration of rare-earth amplifiers and light sources with silicon passive and active devices with no adjustment to standard process flows. The hybrid laser is pumped at standard telecom wavelengths around 1.6 mu m and exhibits stable single-mode emission at 1.9 mu m, with an internal slope efficiency of 60% and >1 mW on-chip output power. The laser is highly promising for emerging communications and sensing applications and opens new possibilities for the development of monolithic rare-earth optical amplifiers and lasers directly on silicon.