LAUSR

All-dielectric metasurfaces provide unique solutions for advanced wavefront manipulation of light with complete control of amplitude and phase at sub-wavelength scales. One limitation, however, for most of these devices is the lack of any post-fabrication tunability of their response. To break this limit, a promising approach is employing phase-change-materials (PCM), which provide a fast, low energy and non-volatile means to endow metasurfaces with a switching mechanism. In this regard, great advancements have been done in the mid infrared and near infrared spectrum using different chalcogenides. In the visible spectral range, however, very few devices have demonstrated full phase manipulation, high efficiencies, and reversible optical modulation. Here, we experimentally demonstrate a programmable all-dielectric Huygens' metasurface made of antimony sulfide (Sb2 S3 ) PCM, a low loss and high-index material in the visible spectral range with a large contrast (∼0.5) between its amorphous and crystalline states. We show ∼2π phase modulation with high associated transmittance and use it to create programmable beam steering devices. These novel chalcogenide PCM metasurfaces have the potential to emerge as a platform for next generation spatial light modulators and to impact application areas such as programmable and adaptive flat optics, LiDAR, and many more. This article is protected by copyright. All rights reserved.