Integrated and Steerable Vortex Lasers using Bound States in Continuum

Orbital angular momentum is a fundamental degree of freedom of light that manifests itself even at the single photon level. The coherent generation and beaming of structured light usually requires bulky and slow components. Using wave singularities known as bound states in continuum, we report an integrated device that simultaneously generates and beams powerful coherent beams carrying orbital angular momentum. The device brings unprecedented opportunities in the manipulation of micro-particles and micro-organisms, and, will also find applications in areas such as biological sensing, microscopy, astronomy, and, high-capacity communications.