Symmetry-free quantum-dot metasurfaces realize arbitrary polarization-direction emission

Abstract Emission from quantum dots is inherently broadband, isotropic, and unpolarized, exhibiting poor spatial and temporal coherence that largely limits their applications in directional and polarization-controlled light sources. While resonant metasurfaces supporting symmetry-protected BICs can enhance emission through high-Q radiative resonances near the BIC in momentum space, their rigid symmetries confine emission to fixed directions and polarization states, preventing robust emission control. Here, we overcome the symmetry-imposed limitations by introducing a symmetry-free resonant metasurface that transforms incoherent quantum dot emission into multiple directional illuminations with designable polarizations and enhanced spatial and temporal coherence. Our recipe allows continuous and robust control of emission while preserving resonance quality. Our approach unifies coherence enhancement and emission shaping within a unified framework, establishing a scalable and versatile platform for active photonic chips and tunable quantum light sources.