The propagation of a femtosecond pulse along the optical axis of a lens is analytically described near the focus assuming homogeneous illumination. The results are compared with previous numerical calculations. The time dependence of the intensity in the focal point is also obtained. For small input beam size the diffraction, for large input beam size the pulse broadening causes the decrease of the intensity in the focal point. There is an optical input beam radius for the highest intensity and an analytical expression is derived for it.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering