Additively Manufactured Multi-Material Ultrathin Metasurfaces for Broadband Circular Polarization Decoupled Beams and...

Area of Science:

• Optics and Photonics
• Metasurface Technology
• Electromagnetic Wave Manipulation

Background:

• Metasurfaces (MSs) are crucial for controlling electromagnetic waves, often combining phases to manipulate circular polarization states.
• Existing MS designs typically integrate propagation and Pancharatnam-Berry phases, limiting independent control of left-hand circular polarization (LCP) and right-hand circular polarization (RCP).

Purpose of the Study:

• To propose a novel strategy for fully decoupling and independently controlling the wavefronts of LCP and RCP waves.
• To demonstrate an ultrathin transmissive metasurface capable of independent LCP and RCP wavefront control using a unique meta-atom design.

Main Methods:

• Utilizing a conductive and dielectric multi-material-integrated additive manufacturing technique to create an ultrathin transmissive metasurface (0.11 free-space wavelength).
• Designing a meta-atom comprising a top receiving antenna, a bottom transmitting antenna, and a connecting strip-line.
• Leveraging the strip-line for identical phase shifts and the transmitting antenna's rotation for opposite phase shifts to LCP and RCP waves, providing two degrees of freedom.

Main Results:

• Achieving independent wavefront control for both LCP and RCP waves under linearly polarized incidence.
• Demonstrating the metasurface's ability to independently shape beams for LCP and RCP waves through combined phase delays and angular rotation.
• Successfully printing two metasurfaces with distinct functionalities for proof-of-concept validation.

Conclusions:

• The proposed metasurface design offers a new paradigm for independent control of circular polarization states.
• Additive manufacturing enables the creation of ultrathin, high-performance metasurfaces for advanced electromagnetic applications.
• Experimental verification confirms the independent beam shaping capabilities for LCP and RCP waves, paving the way for novel optical devices.