Recurring beams in hollow metal waveguides: paraxial approximation

Area of Science:

• Electromagnetics and Optics
• Wave Propagation Physics

Background:

• Directed wave propagation in free space and lenslike media often utilizes Gaussian or Hermite-sinusoidal-Gaussian beams in Cartesian coordinates.
• Recurring beam forms, distinct from continuing beams, have been theoretically possible within the paraxial approximation for specific hollow metal waveguides.

Purpose of the Study:

• To investigate the limitations of the paraxial approximation on recurring beam behavior in hollow metal waveguides.
• To estimate the maximum propagation distance for these recurring beams before significant distortion occurs.

Main Methods:

• Analysis of the paraxial approximation's implications for recurring beam dynamics.
• Derivation of estimates for the maximum propagation distance based on distortion onset.

Main Results:

• The paraxial approximation imposes inherent limitations on the recurrence phenomenon of these beams.
• Quantitative estimates for the maximum propagation distance before significant beam distortion are provided.

Conclusions:

• Understanding these limitations is crucial for practical applications of recurring beams in hollow metal waveguides.
• The findings provide guidance on the operational range for maintaining beam integrity in such systems.