Phys.org May 2, 2022
Active metasurfaces have been proposed as one attractive means of achieving high-resolution spatiotemporal control of optical wavefronts, having applications such as LIDAR and dynamic holography. An international team of researchers (South Korea, USA – University of Wisconsin) has developed an electrically tunable metasurface design strategy that operates near the avoided crossing of two resonances, one a spectrally narrow, over-coupled resonance and the other with a high resonance frequency tunability. It displayed an upper limit of 4Ï€ range of dynamic phase modulation with no significant variations in optical amplitude, by enhancing the phase tunability through utilizing two coupled resonances. A proof-of-concept metasurface was justified analytically and verified numerically in an experimentally accessible platform using quasi-bound states in the continuum and graphene plasmon resonances, with results showing a 3Ï€ phase modulation capacity with a uniform reflection amplitude of ~0.65…read more. Open Access TECHNICAL ARTICLEÂ
Schematic of the metasurface and the band structure of the gratings. Credit: Nature Communications volume 13, Article number: 2103 (2022)Â