Broadband decoupled spin and orbital angular momentum detection via programming dual-twist reactive mesogens

Area of Science:

• Optoelectronics
• Optical Communications
• Photonics

Background:

• Increasing demand for higher optical network capacity necessitates advanced multiplexing techniques.
• Spin and orbital angular momentum mode division multiplexing offer significant capacity expansion potential.
• Development of compatible components is crucial for implementing these advanced techniques.

Purpose of the Study:

• To design and demonstrate a novel component for efficient spin and orbital angular momentum detection.
• To enable broadband, parallel, and decoupled detection of these angular momenta.
• To support the integration of spin and orbital angular momentum multiplexing in optical networks.

Main Methods:

• A geometric phase combined with Dammann vortex and polarization gratings was designed.
• The grating structure was encoded onto a dual-twist reactive mesogen.
• The component's performance was evaluated for broadband operation and spin/orbital angular momentum separation.

Main Results:

• The component efficiently generates dual vortex channel arrays.
• Orthogonal spins are spatially separated, enabling straightforward spin identification.
• Orbital angular momentum is detected by observing vortex recovery to Gaussian beams.

Conclusions:

• A highly efficient, broadband component for decoupled spin and orbital angular momentum detection was developed.
• The design facilitates parallel detection across the visible spectrum.
• This technology holds promise for extending to other optical communication components.