Femtosecond optics—optics of the elementary waves packets

We have critically reconsidered the standard representation of optical signals in the form of quasimonochromatic electromagnetic waves. We propose an alternative formulation in terms of ortho-normalized series of elementary wave packages (EWP). We show that this allows the synthesis and analysis of superwideband optical signals, for example, femtosecond optical pulses (fs pulse). In addition, it includes the general properties of electromagnetic waves. We also propose a technique for describing the polarization and angular momentum of the fs pulse. As examples of the application of the proposed EWP representation, we investigated nonstationary diffraction of fs pulse of any duration by a slit and interaction of the fs pulse with a two-level system. We have established the resonant character of these processes over the duration of the fs pulse.