Near-infrared vortex emission from halide perovskite via a quasi-guided-mode-coupled bound state in the continuum

Abstract

Bound states in the continuum (BICs) present a promising quantum optics platform, yet their inherent field confinement typically limits the local density of optical states (LDOS) for emitters unless active materials are directly patterned into BIC structures. This constraint is particularly acute for solution-processed emitters. Here, we demonstrate a quasi-guided-mode-coupled second-order BIC in silicon metasurfaces that simultaneously ensures the LDOS within the emission layer and the light–matter interaction strength. This mechanism avoids complex direct patterning of active materials and enables the first observation of vortex emission from halide perovskites at 1 μm wavelength. At the same time, efficient spatial overlap between perovskite emitters and photonic modes realizes enhanced near-infrared emission coherence from perovskites and >50 nm emission wavelength tuning through metasurface parameter adjustments─the broadest reported range to date. This work provides critical insights for developing CMOS-compatible perovskite light sources leveraging BIC physics.