Multifunctional terahertz metasurfaces for polarization transformation and wavefront manipulation.

Area of Science:

• Optics and Photonics
• Metamaterials
• Terahertz Technology

Background:

• Metasurfaces traditionally use Pancharatnam-Berry (PB) and dynamic phases for polarization control.
• Existing methods are limited to spin-dependent wavefront manipulation for circular polarization (CP).

Purpose of the Study:

• To develop a novel metasurface technology for versatile polarization transformation and wavefront manipulation.
• To overcome limitations of spin-dependent control for circular polarization.

Main Methods:

• Utilizing dynamic phase with a spatial interleaving unit arrangement in metasurface design.
• Designing a bifocal metasurface capable of multiple wavefront manipulations.
• Theoretical proof of independent manipulation for linear polarization (LP) components under arbitrary CP incidence.

Main Results:

• Achieved multiple wavefront manipulations for both spin and linear polarization transformations.
• Demonstrated a bifocal metasurface focusing CP components differently under LP incidence.
• Showcased independent manipulation of x-LP and y-LP components under arbitrary CP incidence.

Conclusions:

• The proposed dynamic phase metasurface offers versatile polarization and wavefront control beyond traditional PB phase methods.
• This technology enables independent manipulation of different polarization states, including linear polarization.
• The developed method provides a versatile platform for advancing terahertz integrated photonics.