Abstract
We compare the Fresnel diffraction pattern of a thin circular disk with that of a square obstacle, specifically evaluating the on-axis field strength. Photographs of the diffraction patterns reveal some curious features for the square obstacle. Second, the precise electric and magnetic fields behind a conducting circular disk are evaluated without invoking the Fresnel approximation and contrasted with the rigorous electromagnetic result for a metal sphere. The calculations show that the two cases differ only slightly in the Fresnel region. In the near-field new computational results for the sphere are analyzed.
© 1988 Optical Society of America
Full Article | PDF ArticleMore Like This
Gary E. Sommargren and H. Joseph Weaver
Appl. Opt. 29(31) 4646-4657 (1990)
Petras V. Avizonis, Janet S. Fender, and Robert R. Butts
Appl. Opt. 28(1) 163-172 (1989)
C. L. Andrews, Intaik Chung, and L.F. Libelo
J. Opt. Soc. Am. 70(7) 813-816 (1980)