Abstract

It was shown in [1-3] that the chromatic aberration of a lens causes a distortion of a femtosecond pulse front. In this paper the behaviour of the pulse front in the vicinity of a lens is described by using wave optics. For the calculation the input pulse (6 fs, 620 nm) is decomposed into monochromatic plane waves, which are converted by the lens into Airy-type of diffraction patterns. Due to chromatic aberration the positions of the diffraction patterns are slightly shifted with respect to each other along the optical axis. The pulse front is obtained as a result of the superposition of diffraction patterns of the components [4]. The calculation were made for BK7 lenses having the same focal length (f=30 mm) but different diameters (d=1,2,4,7 and 10 mm). The total input energy of the pulse was regarded to be constant. Spatially homogeneous illumination was assumed.

© 1992 The Author(s)