Dynamic shaping of orbital-angular-momentum beams for information encoding.

Area of Science:

• Optics and Photonics
• Optical Communication

Background:

• Digital micromirror devices (DMDs) are increasingly used for complex optical field shaping.
• Orbital-angular-momentum (OAM) beams offer potential for advanced optical communication and microscopy.

Purpose of the Study:

• To present an optimized method for dynamic OAM beam shaping using a binary DMD.
• To enhance hologram design accuracy for high-fidelity wavefront shaping.

Main Methods:

• Utilized an optimized Lee method combined with an error diffusion algorithm for binary-amplitude hologram design.
• Employed a digital micromirror device (DMD) for dynamic wavefront control.
• Performed numerical simulations and experimental demonstrations.

Main Results:

• Achieved high fidelity (F > 0.985) for various OAM fields with independent phase and amplitude modulation.
• Experimentally demonstrated dynamic shaping of pure and mixed OAM modes.
• Reached a high switching rate of up to 17.8 kHz for OAM beam generation.

Conclusions:

• The optimized Lee method with error diffusion enables high-fidelity dynamic OAM beam shaping using binary DMDs.
• This technique supports accurate information encoding into multiplexed OAM beams.
• Paves the way for high-speed classical and quantum communications utilizing spatial mode encoding.