Diffraction by apodized apertures

This paper investigates the diffraction of light by apodized apertures. The diffraction equation is solved numerically starting with an apertured plane wave or Gaussian beam. A function chosen to characterize spatial intensity modulation is then plotted versus Fresnel number for differing amounts of apodization so that the benefit gained thereby may be quantitatively assessed. In addition, the energy loss incurred due to insertion of an apodized aperture in front of an existing hard aperture is determined.