Far and near fields of Hermite-Gaussian beams passing through an annular aperture and its numerical simulation by the angular spectrum method.

This research focuses on the analysis of the free propagation of Hermite-Gaussian beams diffracted by a symmetrical annular aperture placed at the beam waist plane. The propagation is studied analytically and numerically using the angular spectrum method and the 2D fast Fourier transformation. Numerical simulation examples illustrate the propagation characteristics of the Hermite-Gaussian beams diffracted by an annular aperture. The beam truncation parameters and obscuration ratio influence Hermite-Gaussian beam diffraction properties. [ABSTRACT FROM AUTHOR]