Accession Number : AD0781129

Title :   The Fresnel Diffraction Pattern of a Circular Aperture at Large Distances.

Descriptive Note : Rept for Apr-Nov 73,


Personal Author(s) : Tavis,M. T. ; Chang,N. C.

Report Date : 15 MAR 1974

Pagination or Media Count : 65

Abstract : A technique for evaluation of the Fresnel diffraction pattern of a circular aperture with obscuration is discussed. The analysis considers Gaussian illumination over the aperture with constant illumination as the limiting case of infinite beam width. A lens correction factor is also applied. Examples of the pattern in the near region and Rayleigh region are given. Examples with lenses with positive and negative focal lengths are also given. All numerical cases considered are for constant illumination. A computer program for the calculation is given in the Appendix. An Addendum comparing these results with the results of another author has been included. (Author)

Descriptors :   *Apertures, *Diffraction, Circular, Laser beams, Computer programs

Subject Categories : Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE