Chiral quasi bound states in the continuum for a high-purity circularly polarized light source

An ultracompact circularly polarized light source is a crucial component for the applications of classical and quantum optics information processing. The development of this field relies on the advances of two fields: quantum materials and chiral optical cavities. Conventional approaches for circularly polarized photoluminescence suffer from incoherent broadband emission, limited DOP, and large radiating angles. Their practical applications are constrained by low efficiency and energy waste to u...