This work was undertaken with a view to study the effects, which may be produced, in the Fresnel diffraction patterns of narrow obstacles, keeping the boundary the same (namely straight) and changing the shape of the cross section. Visible monochromatic light was used as a source and photometric analysis of the intensity distribution patterns was made. The experimental curves deviate from those obtained according to the classical Fresnel-Kirchhoff theory of diffraction and show a boundary effect. If a comparison of the experimental curves for tapes and wires is made with the theoretical curves, the tape curves appear to be a little better in agreement than the wire curves. Additional experiments performed indicate that the observed deviations are not the result of surface reflections from the obstacles.
A. P. THATTE, "An Experimental Study of Diffraction Showing the Boundary Effect," J. Opt. Soc. Am. 42, 166-170 (1952)