On-chip coherent light sources are a cornerstone of integrated photonics, yet current nanolasers face fundamental limitations due to fabrication-induced scattering losses. This project pursues a bottom-up epitaxial approach to nanolaser cavities, where atomically smooth crystal facets naturally formed during growth eliminate the defects inherent to top-down fabrication. These high-quality, sub-wavelength dielectric cavities confine light with exceptional efficiency, enabling stronger light–matter interaction and reduced lasing thresholds.

Building on recent demonstrations of bottom-up micro-rings, nanowires, photonic crystal surface-emitting lasers (PCSELs), and quasi-bound state in the continuum (BIC) metasurfaces, the research will push towards next-generation designs, including flatband and topological nanolasers. By leveraging unique photonic band structures, these novel cavities promise robust, scalable, and disorder-immune operation. Ultimately, the project seeks to redefine nanoscale laser technology, opening new pathways for compact, high-performance photonic integration.