Terahertz-Wave Polarization Space-Division Multiplexing Meta-Devices based on Spin-Decoupled Phase Control.

Area of Science:

• Optics and Photonics
• Metamaterials Science
• Terahertz Technology

Background:

• Metasurfaces offer advanced control over light polarization.
• Terahertz (THz) wave applications require sophisticated polarization manipulation.
• Existing meta-devices often lack flexibility in multi-beam polarization control.

Purpose of the Study:

• To present a generalized design strategy for novel terahertz-wave polarization space-division multiplexing meta-devices.
• To enable multi-polarization generation, modulation, and analysis.
• To achieve flexible control over polarization directions and spatial distributions of multiple output beams.

Main Methods:

• Introduced a spin-decoupled phase control method.
• Combined gradient phase design with circular polarization multiplexing.
• Utilized all-dielectric metasurfaces for meta-device fabrication.

Main Results:

• Demonstrated meta-device M-4D converting linear polarization into four distinct beams.
• Designed meta-devices M-2B and M-4B for generating vector Bessel beams with tunable polarization.
• Validated dynamic multi-polarization beam modulation through simulations and experiments.

Conclusions:

• The proposed method expands design methodologies for multi-beam polarization control.
• The meta-devices show potential for THz imaging, sensing, communication, and information processing.
• The design strategy is adaptable to other spectral ranges.