Bottom-up, chip-scale engineering of low threshold, multi-quantum well microring lasers

Integrated, on-chip lasers are vital building blocks in future optoelectronic and nanophotonic circuitry. Specifically, III-V materials that are of technological relevance attract considerable attention. However, traditional micro-cavity laser fabrication techniques, including top-down etching and bottom-up catalytic growth, often result in undesirable cavity geometries with poor scalability and reproducibility. Here, we utilize the selective area epitaxy method to deterministically engineer thousands of micro-ring lasers on a single chip. Specifically, we realize a catalyst-free, epitaxial growth of a technologically-critical material, InAsP/InP, in a ring-like cavity with embedded multi-quantum wells heterostructures. We elucidate a detailed growth mechanism and leverage the capability to deterministically control the adatom diffusion lengths on selected crystal facets to reproducibly achieve ultra-smooth cavity sidewalls. The engineered devices exhibit tunable emission wavelength in the telecommunication O-band and show low-threshold lasing with over 80% device efficacy across the chip. Our work marks a significant milestone towards the implementation of fully integrated III-V materials platform for next-generation high-density integrated photonic and optoelectronic circuits.