High purity orbital angular momentum of light

Area of Science:

• Optics and Photonics
• Quantum Information Science

Background:

• Orbital angular momentum (OAM) light beams offer unique properties for applications in communication and microscopy.
• Existing methods for generating OAM beams often suffer from low mode purity and significant beam divergence.
• Controlling singularity splitting and beam divergence is crucial for practical OAM applications.

Purpose of the Study:

• To introduce a novel technique for generating OAM beams with enhanced mode purity and controlled divergence.
• To analyze a tunable parameter for optimizing the trade-off between beam purity and power.
• To demonstrate a simplified experimental setup using only phase-modulating optical elements.

Main Methods:

• Development of a new optical configuration for OAM beam generation.
• Analysis of beam propagation characteristics, including mode purity and divergence.
• Investigation of a tunable parameter influencing the purity-to-power ratio.
• Experimental validation using phase-only optical elements.

Main Results:

• Achieved orders-of-magnitude reduction in singularity splitting and increase in mode purity.
• Demonstrated effective control and mitigation of beam divergence within the Rayleigh length.
• Identified a tunable parameter allowing adjustment of the purity-to-power ratio.
• Confirmed feasibility using only phase-modulating elements, reducing complexity and energy loss.

Conclusions:

• The presented technique offers a significant advancement in OAM beam generation.
• This method provides a flexible and efficient approach for producing high-quality OAM beams.
• The simplified experimental requirements make this technique highly attractive for various applications.