Previous asymptotic expansions of the diffraction integral are valid for only certain regions in the observation plane. This paper gives a method for calculating semiuniform expansions that are valid in the intermediate regions. They are especially useful and simple for the near-axis field of a circularly symmetric aperture. The case for circularly symmetric ρ<sup>2v.</sup> aberrations is presented.
© 1980 Optical Society of America
E. Loh, Jr., "Semiuniform asymptotic expansions of the diffraction integral," J. Opt. Soc. Am. 70, 1075-1079 (1980)