Rapid Polarization-Controlled Depth Sensing and Imaging with an Electrically Tunable Metalens

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• Metasurfaces offer advanced optical functionalities.
• Controlling light polarization is crucial for advanced imaging.
• Liquid crystals provide tunable optical properties.

Purpose of the Study:

• To demonstrate an electrically tunable metalens for polarization-controlled imaging and depth sensing.
• To integrate hydrogenated amorphous silicon meta-atoms with a liquid crystal layer.
• To achieve millisecond-scale reconfiguration of optical functions.

Main Methods:

• Fabrication of a metalens combining hydrogenated amorphous silicon meta-atoms and a liquid crystal layer.
• Encoding independent focusing profiles for LCP and RCP light using propagation and geometric phases.
• Electrical tuning of the liquid crystal layer and manipulation of incident polarization states.

Main Results:

• The metalens demonstrated independent focusing for LCP and RCP light.
• Millisecond-scale reconfiguration of focusing profiles was achieved by adjusting LC voltage and polarization.
• Linearly polarized light produced two rotating images, encoding object depth.
• Experimental results validated theoretical predictions, including a full π rotation during focal scanning.

Conclusions:

• The developed metalens is a compact, real-time platform for polarization-controlled imaging and depth sensing.
• This technology has potential applications in microscopy, holography, and adaptive optics.
• Electrically tunable metalenses offer versatile solutions for advanced optical systems.