Abstract

We present a precise calculation of the fields behind a conducting circular disk. The only assumption inherent in the calculation is that the true aperture field is approximated by the incident field. We compare this result with the rigorous electromagnetic calculation behind a perfectly conducting metal sphere. Although these are two physically different problems, one nonetheless expects certain similarities in their diffraction patterns. The calculations show that the two cases differ only slightly in the Fresnel region (paraxial). For the near field we present a detailed discussion of the differences. A numerical example is given, and photographs of the shadow region diffraction patterns are compared.

© 1987 Optical Society of America