Spatial aliasing based complementary meta-gratings for the high-efficient generation of different polarized multiple...

Area of Science:

• Optics and Photonics
• Metamaterials
• Electromagnetics

Background:

• Metasurfaces offer precise control over light polarization and wavefronts.
• Generating multiple beams with distinct polarizations from a single device is challenging.
• Birefringent metasurfaces provide a pathway for polarization manipulation.

Purpose of the Study:

• To demonstrate the synthesis of split dual circularly polarized (CP) beams with simultaneous linearly polarized (LP) radiation.
• To explore the capability of dual superposed birefringent meta-surface lenses for generating multiple beams with defined polarization states.
• To investigate the aperture efficiency of this meta-surface configuration for advanced spatial-phase engineering.

Main Methods:

• Synthesis of dual superposed birefringent meta-surface lenses using zebra crossing shaped meta-gratings.
• Designing meta-gratings to generate CP refractions with different helicities.
• Arranging meta-gratings complementarily to achieve spatial aliasing and multiple-beam generation.

Main Results:

• Successfully generated triple beams with distinct polarizations: left-hand CP (LHCP), right-hand CP (RHCP), and co-/cross-LP waves.
• Demonstrated that the polarization states of the triple-beam radiation can be precisely defined.
• Achieved promising aperture efficiencies for multiple-beam generation through the complementary arrangement of meta-gratings.

Conclusions:

• Dual superposed birefringent meta-surface lenses can simultaneously generate split dual CP beams and an additional LP beam.
• This approach enables tailored spatial-phase engineering with specific radiating characteristics.
• The findings pave the way for advanced applications in optical beam manipulation and meta-surface technology.