Propagating free-space nonparaxial beams.

Area of Science:

• Optics and Photonics
• Computational Electromagnetics
• Beam Propagation

Background:

• Accurate modeling of nonparaxial beams is crucial for advanced optical applications.
• Existing methods may lack precision or computational efficiency for complex beam structures.

Purpose of the Study:

• To develop and validate a novel iterative method for propagating the transverse component of nonparaxial beams.
• To provide a computationally efficient and accurate alternative to existing beam propagation techniques.

Main Methods:

• Simultaneous combination of the propagation operator and Fourier transform with an arbitrary index.
• Iterative computational implementation for propagating transverse field structures in free space.

Main Results:

• The method successfully propagates nonparaxial beams from arbitrary initial transverse field structures.
• Closed-form nonparaxial corrections for Bessel-Gaussian beams were derived, showing significant differences from previous results.
• The approach's validity was confirmed using a recently introduced paraxiality estimator.

Conclusions:

• The developed iterative method offers a robust and accurate solution for nonparaxial beam propagation.
• The findings challenge previous theoretical results for Bessel-Gaussian beams, highlighting the method's distinct capabilities.
• This technique provides a valuable tool for research and applications involving complex optical beams.