We describe the interference between two caustics of diffraction fields that are generated in a double-curve-shaped-slit interferometer. One of the slits is obtained from the other through a projective mapping in the normal direction. In this way the diffraction fields present the same caustic region because the slit functions have a common evolute. Catastrophe functions are used for describing the optical path length of the rays involved. We show that the phase difference between the diffracted rays can also be considered a catastrophe function, which permits us to describe the geometry of the interference pattern because its singular points correspond to organized regions of the interference pattern. Experimental results are shown.
© 1999 Optical Society of America
(050.1940) Diffraction and gratings : Diffraction
(050.1960) Diffraction and gratings : Diffraction theory
(080.1510) Geometric optics : Propagation methods
(260.3160) Physical optics : Interference
Gabriel Martínez-Niconoff, Javier Muñoz-Lopez, and Alejandro Cornejo-Rodriguez, "Interference between two diffraction fields with a common caustic region," J. Opt. Soc. Am. A 16, 1970-1973 (1999)