Dispersive distortions correction of femtosecond pulses because of the surface shape choice of a diffraction optical element

Specific features of femtosecond pulses transmission through a focusing diffraction optical element are considered. It is shown that the time delay between the pulse and phase wave fronts can be decreased if a diffraction optical element is fabricated on an optimal curvilinear surface. The introduction of the non-plane surface allows one to reduce the dispersive distortions of femtosecond pulses in comparison with the diffraction optical elements on a plane surface.