Application of unfolding technique to dispersion calculating of reflective grating dispersion delay lines in the chirped pulses amplifier

Dispersion delay lines (such as the compressor and the stretcher) consisting of reflective optical elements (mirrors and reflection diffraction gratings), are now widely used in chirped-pulse amplification technique. It is shown that for their calculations the unfolding technique can be applied. According to this technique, the dispersion of the compressor and the stretcher can be characterized by the "zero-distant pulse fronts" in their spatial chirps.