Die allgemeine Intensitätsverteilung in der kohärent ausgeleuchteten Umgebung einer Kaustikfläche
It is found that in the case of coherent irradiation the intensity distribution in the near vicinity of any regular caustic surface is described by the same Airy integral. The scale in which the distance of intensity maxima and minima is measured depends only on the wave length and the difference of the curvatures of the tangent electron ray and the circle of curvature to which this ray is tangent. This result is confirmed by a simple light optical experiment. For the case of a charged particle in a homogeneous field the result of a direct wave mechanical calculation is in agreement with the above approximation in which some concepts of geometrical optics were used.