Hybrid-2D Excitonic Metasurfaces for Complex Amplitude Modulation

Area of Science:

• Metasurface technology
• Optoelectronics
• Nanophotonics

Background:

• Dynamic control of visible light is essential for holographic displays and adaptive optics.
• Current active metasurfaces struggle with simultaneous phase and amplitude modulation.
• Existing metasurfaces often exhibit amplitude variations during broad phase modulation.

Purpose of the Study:

• To demonstrate a hybrid-2D excitonic metasurface for independent amplitude and phase control in the visible spectrum.
• To leverage gate-tunable excitonic responses for dynamic wavefront shaping.
• To design a reconfigurable beam-steering metadevice.

Main Methods:

• Utilizing an inverse-design pipeline for numerical demonstration.
• Employing gate-tunable excitonic response of monolayer WS2.
• Integrating a second tunable monolayer for enhanced control.

Main Results:

• Achieved independent amplitude and phase control over the full 0-2π phase range.
• Designed a π-phase modulator with a uniform amplitude profile.
• Demonstrated a reconfigurable beam-steering metadevice using the designed metasurface.

Conclusions:

• Hybrid-2D excitonic metasurfaces enable electrically tunable wavefront shaping in the visible regime.
• This platform overcomes limitations of previous metasurfaces in dynamic phase and amplitude control.
• The developed technology paves the way for advanced optical devices.