Phys.org  May 26, 2023 Compared to metasurfaces composed of the periodic arrangement of nanoparticles, inverse membrane metasurfaces offer unique possibilities for supporting multipolar resonances, while maintaining small unit cell size, large mode volume and high field enhancement for enhancing nonlinear frequency conversion. An international team of researchers (UK, Australia, China, Hong Kong) theoretically and experimentally investigated the formation of bound states in the continuum (BICs) from silicon dimer-hole membrane metasurfaces, and demonstrated that BIC-formed resonance featured a strong and tailorable electric near-field confinement inside the silicon membrane films. They showed that by tuning the gap between the holes, it is […]