Discontinuous orbital angular momentum metasurface holography

Area of Science:

• Optics and Photonics
• Information Security
• Metasurface Technology

Background:

• Orbital angular momentum (OAM) multiplexing holography is key for high-capacity optical systems.
• Conventional OAM modes face security limitations due to rotational symmetry, requiring multiple inputs for decoding.

Purpose of the Study:

• To introduce a novel OAM multiplexing holography paradigm for multi-channel holographic encoding with a single incident light.
• To enhance the security and channel capacity of optical information encryption and communication systems.

Main Methods:

• Leveraging discontinuous OAM with spatially varying topological charge (TC) to break rotational symmetry and enable angular selectivity.
• Developing a modified weighted Gerchberg-Saxton algorithm for holographic phase profile calculation.
• Encoding the holographic profile onto a pure geometry-phase metasurface.

Main Results:

• Demonstrated discontinuous OAM's self-orthogonality at different rotation angles, enabling multiplexed holography.
• Successfully expanded channel capacity for holographic multiplexing by integrating discontinuous OAM pairs.
• Achieved significant advancements in high-security and high-capacity optical information encryption.

Conclusions:

• Discontinuous OAM provides a versatile platform for secure optical communications, high-density data storage, and dynamic holographic displays.
• This approach bridges structured light manipulation with cryptographic robustness.
• The methodology overcomes limitations of conventional OAM modes, paving the way for next-generation optical technologies.