Intensity analysis on caustic of autofocusing chirp beams

For autofocusing beams formed by a generalized lens, an expression is obtained for the amplitude and intensity of the field along the caustic line. We have considered three types of incident beam amplitude: constant, power-law and generalized exponential. In the first two cases, the dependence of intensity on distance will be monotonous; in particular, it may be constant. At the amplitude of the incident beam of the third type, the intensity dependence has a single maximum point.