Plasmonic Metasurfaces for Switchable Photonic Spin-Orbit Interactions Based on Phase Change Materials

Area of Science:

• Photonics and Nanotechnology
• Metasurface Optics
• Phase Change Materials

Background:

• Metasurfaces enable precise control of light polarization and wavefront.
• Achieving reconfigurable optical functionalities in metasurfaces remains a significant challenge due to fixed optical performance post-fabrication.

Purpose of the Study:

• To demonstrate switchable spin-orbit interactions (SOIs) in plasmonic metasurfaces by integrating phase change materials (PCMs).
• To develop reconfigurable metadevices for dynamic manipulation of light polarization and wavefront.

Main Methods:

• Numerical and experimental investigation of plasmonic metasurfaces combined with phase change materials (PCMs).
• Fabrication and characterization of three metadevices exhibiting switchable SOIs.

Main Results:

• Demonstrated switchable SOIs enabling spin Hall effect, vortex beam generation, and holography in the amorphous state (ON) and their disappearance in the crystalline state (OFF).
• Achieved high polarization conversion contrast between ON and OFF states over a broadband wavelength range (8.5–10.5 µm).

Conclusions:

• The proposed switchable photonic SOIs offer a promising pathway for designing reconfigurable optical devices.
• Potential applications include beam steering, dynamic holographic displays, and secure optical communications.