The paper presents an asymptotic expression of relative intensity distribution in a Fresnel diffraction pattern at an opaque straight strip illuminated with a spherical wave. The asymptotic expression is used in an analysis showing an area of validity where the asymptotic expression reduces to an asymptotic expression of relative intensity distribution in a Fresnel diffraction at a half plane. The area of validity is defined through width of the geometrical shadow in a Fresnel diffraction pattern at an opaque straight strip and distance of a point under study to the center of the Fresnel diffraction pattern. Within this area, relative intensity in the Fresnel diffraction pattern at an opaque straight strip shows sinusoidal behavior, which can be used in easy location of maxima or minima of the relative intensity. The result of the analysis is supported by experiments realized in the area of validity and outside it.
© 2012 Optical Society of America
Diffraction and Gratings
Original Manuscript: December 14, 2011
Revised Manuscript: February 16, 2012
Manuscript Accepted: February 27, 2012
Published: May 30, 2012
Petr Šmíd and Pavel Horváth, "Fresnel diffraction at an opaque strip expressed by means of asymptotic representations of Fresnel integrals," J. Opt. Soc. Am. A 29, 1071-1077 (2012)