Distortion of femtosecond pulses in lenses. Wave optical description

Abstract The propagation and distortion of a 100 fs long pulse in a silica lens is described using wave optical theory. A fifty-fold increase of the pulse duration was calculated. The intensity distribution in the focal plane turned to be essentially different from the Airy pattern. Furthermore, the formation of a forerunner pulse is predicted. The forerunner is caused by the interference of the boundary waves generated by the aperture of the lens. Approximate analytical solutions for the diffraction of fs pulses are also given.