Axial intensity oscillation suppression for plane-wave diffraction from a circular hole: Flattened Gaussian apodization

The flattened Gaussian apodization technique is employed to suppress the axial intensity oscillations, when a plane wave diffracts from a circular hole. Under different apodization parameters, the field intensities are simulated by the complete Rayleigh–Sommerfeld method in the scalar diffraction domain. Numerical results reveal that the axial intensity is uniform in a considerably long propagating range, within which the transverse intensity is also maintained stably. In addition, the flattened Gaussian apodization technique performs well in a wide wavelength band. It is expected to have many practical applications in optical coupling and optical communication systems.