Unified and accurate diffraction calculation between two concentric cylindrical surfaces.

Area of Science:

• Optics and Photonics
• Computational Electromagnetics
• Wave Propagation

Background:

• Accurate diffraction calculations are crucial for modeling wave phenomena.
• Existing methods for concentric cylindrical surfaces often have limitations in accuracy or scope.
• The obliquity factor's physical interpretation has been a subject of study.

Purpose of the Study:

• To propose a unified and accurate fast diffraction calculation method for concentric cylindrical surfaces.
• To clarify the physical meaning of the obliquity factor in this context.
• To develop an accelerated computational approach for diffraction problems.

Main Methods:

• Developed a unified diffraction calculation formula applicable to both inside-out and outside-in propagation.
• Interpreted the obliquity factor as a projection of the complex amplitude.
• Implemented a fast calculation method utilizing Fast Fourier Transformation (FFT).

Main Results:

• Achieved a unified and accurate diffraction calculation for concentric cylinders.
• Demonstrated a speed-up factor exceeding 3.9×10^6 compared to direct methods.
• Identified significant computing errors in approximate inside-out propagation models.
• Removed limitations on cylinder radius and height ratios.

Conclusions:

• The proposed unified method provides accurate diffraction calculations for concentric cylinders.
• The FFT-accelerated approach offers substantial computational efficiency.
• The findings highlight the inaccuracies of prior approximate models and offer a more robust solution.