Passive metasurfaces suffer from a complex balancing of their nonlinear efficiency, phase modulation capabilities and directionality. Here, authors propose a nonlocal meta-lens integrating Mie-type resonances with quasi-bound states in the continuum. Driven by the asymmetry of a low-index silica substrate, they realize directional response with a forward-to-backward ratio of up to 10 dB.
- Jin Yao
- Zhihui Wang
- Din Ping Tsai