Multi-channel orbital angular momentum detection with metahologram.

Area of Science:

• Optics and Photonics
• Metamaterials
• Light-Matter Interactions

Background:

• Orbital angular momentum (OAM) is a key property of light with growing importance in various applications.
• Accurate detection of OAM states is critical for harnessing its potential in fields like optical communications.

Purpose of the Study:

• To propose a novel method for extending the detectable range of orbital angular momentum (OAM) states.
• To enhance the fidelity of OAM state identification.

Main Methods:

• Utilized a multi-sector metahologram to focus incident light carrying OAM.
• Converted OAM light into surface plasmon waves with distinct propagation directions.
• Employed multiple subwavelength detectors to spatially sample the surface plasmon waves.
• Quantized and mapped detector signals into a lookup table for OAM state distinction.

Main Results:

• Successfully demonstrated a method to extend the detectable range of OAM states.
• Achieved high-fidelity discernment of various OAM states.
• The multi-sector metahologram effectively separates and samples OAM-encoded surface plasmon waves.

Conclusions:

• The proposed multi-sector metahologram offers a powerful approach for high-fidelity OAM state detection.
• This principle holds significant promise for advancements in optical communications and information processing utilizing OAM states.