High-Performance Reconfigurable Infrared Metasurfaces with Phase-Change Materials

Optical metastructures and metasurfaces are emerging with properties that could support the development of flat optics with aberration correction, ultrathin focusing lenses, resonant absorbers, polarimeters without moving parts, phase shifters, and holograms. Optical metasurfaces consisting of subwavelength optical resonators or antennas can provide control over the phase, amplitude, and polarization of incoming light, beyond what classical refractive and diffractive optical components can offer. Currently, there is growing interest in reconfigurable or tunable metasurfaces, which can add additional functionality enabling multi-functional dynamic optical components. Phase change materials (PCMs) have been recently explored for reconfigurable optical devices such as spatial light modulators [1,2] and metasurfaces [3,4], where the PCM-based reconfigurable resonant absorber concept has been demonstrated with an optical reflectance contrast of 40% - 75% in the Near-Infrared spectral range.<br/>In this talk, we will present large-scale reconfigurable infrared metasurfaces consisting of greater than 30 million pixelated optical antennas integrated with PCM mesa structures over a 1cm x 1cm area, where the metasurfaces demonstrate 99% resonant absorption and state-of-the-art optical reflectance contrast at off-resonant wavelengths.<br/> <br/>[1] J. S. Moon et al., Proc. of SPIE Vol. 10982, 2019<br/>[2] J. S. Moon et al., Proc. of SPIE Vol. 11389, 2020<br/>[3] Y. Zhang et al., <i>Nat. Nanotechnol.</i> <b>16</b>, 661–666 (2021)<br/>[4] S. Abdollahramezani et al., arXiv:2014.10381 (2021)