Programmable Wavefront Control in the Visible Spectrum Using Low-Loss Chalcogenide Phase-Change Metasurfaces

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• All-dielectric metasurfaces offer precise light control but typically lack post-fabrication tunability.
• Phase-change materials (PCMs) provide a promising route for tunable metasurfaces, with advancements mainly in infrared spectra.
• Few visible-spectrum devices achieve full phase manipulation, high efficiency, and reversible modulation.

Purpose of the Study:

• To demonstrate a programmable all-dielectric Huygens' metasurface operating in the visible spectral range.
• To utilize antimony sulfide (Sb2S3) as a phase-change material for tunable optical responses.
• To create programmable beam-steering devices with high efficiency and reversible modulation.

Main Methods:

• Fabrication of an all-dielectric Huygens' metasurface using antimony sulfide (Sb2S3).
• Characterization of Sb2S3's optical properties, noting its low loss, high refractive index, and significant contrast between amorphous and crystalline states.
• Experimental demonstration of ≈2π phase modulation with high transmittance.

Main Results:

• Successful implementation of a programmable metasurface in the visible spectrum using Sb2S3.
• Achieved ≈2π phase modulation with high optical transmittance.
• Demonstrated programmable beam-steering capabilities using the tunable metasurface.

Conclusions:

• Antimony sulfide (Sb2S3) is a viable PCM for visible-light metasurfaces, offering significant optical contrast.
• The developed metasurface enables programmable beam steering and holds potential for spatial light modulators.
• These chalcogenide PCM metasurfaces pave the way for adaptive optics, LiDAR, and other advanced photonic applications.