Vortex nanolaser based on a photonic disclination cavity

Photonic topological insulators that exploit topological defects of disclinations provide a robust solution for light manipulation to form compact optical vortices and on-chip integration with reduced scattering loss and energy consumption. In this work, we demonstrate wavelength-scale, low-threshold, vortex and anti-vortex nanolasers in an optical cavity formed by a topological disclination. Various photonic disclination cavities are designed and analyzed using the similarities between tight-binding models and optical simulations. Unique resonant modes are strongly confined in these cavities, which exhibit wavelength-scale mode volumes and retain topological charges in the disclination geometries. In the experiment, the optical vortices of the lasing modes are clearly identified by measuring polarization-resolved images, Stokes parameters and self-interference patterns. Specifically, we measure topological charges of 1 and 2 in C5 and C6 disclination cavities, respectively. This work paves the way for the application of advanced nanophotonic devices in laser technology and high-precision optical communications.