Manipulation and control of 3-D caustic beams over an arbitrary trajectory

Area of Science:

• Optics and Photonics
• Computational Electromagnetics
• Beam Shaping

Background:

• Controlling light propagation in free space is crucial for applications like optical manipulation and wireless power transfer.
• Existing methods often struggle with complex, arbitrary trajectories and precise energy confinement.

Purpose of the Study:

• To develop a robust algorithm for manipulating 3-D field patterns with energy confined to arbitrary 3-D trajectories.
• To enable precise control over both the on-axis intensity profile and off-axis beam-width.

Main Methods:

• Utilizing aperture field phase to generate smooth caustic surfaces containing the desired trajectory.
• Iteratively updating aperture amplitude distribution for intensity and beam-width control.
• Numerical computation of radiation from finite apertures using Fast Fourier Transform (FFT) schemes.

Main Results:

• Demonstrated successful confinement of energy along planar, helical, and conical-helical trajectories.
• Verified the algorithm's design and assessed sensitivity to discrete implementation parameters.
• Showcased the generation of Airy beams along planar trajectories.

Conclusions:

• The presented algorithm offers precise control over 3-D light field propagation along complex paths.
• The method is suitable for realistic discrete implementations and various trajectory types.
• This work advances capabilities in free-space optical field manipulation.