High-dimensional information encoding with low-divergence rotating gear vortex beams

Area of Science:

• Optical Communications
• Structured Light Fields
• Free-Space Optics (FSO)

Background:

• Vortex beams with orbital angular momentum (OAM) are crucial in FSO communication due to their helical phase structures.
• Expanding light field degrees of freedom is key for enhancing communication capacity.

Purpose of the Study:

• To propose and investigate a novel structured light field, the rotating gear vortex beam (RGVB).
• To evaluate the RGVB's potential for high-dimensional information encoding and its performance in atmospheric turbulence.

Main Methods:

• Constructing the RGVB through mode superposition of two-dimensional Laguerre-Gaussian (LG) beams.
• Analyzing the RGVB's propagation characteristics and intensity distribution.
• Performing numerical simulations to compare encoding capacity with LG beams.
• Validating performance by transmitting grayscale images through simulated atmospheric turbulence.

Main Results:

• The RGVB exhibits a unique rotating gear intensity distribution and low divergence.
• RGVBs possess four tunable parameters, enabling high-dimensional encoding with 204 available modes (3.19x more than LG beams).
• RGVBs demonstrate superior turbulence resilience, achieving up to 25.14% higher recognition accuracy than LG beams in strong turbulence.

Conclusions:

• RGVBs offer significantly enhanced encoding capacity due to their tunable parameters.
• The RGVB shows remarkable resilience to atmospheric turbulence, outperforming conventional LG beams.
• RGVBs hold great potential for future high-capacity and robust free-space optical communication systems.