NONUNIFORM OPTICAL DIFFRACTION GRATINGS FOR LASER-PULSE COMPRESSION

It is shown that a pair of perpendicular optical diffraction gratings leads to a time delay which grows strictly linearly as a function of f requency. Such a device associated with a simple nonuniform diffractio n grating allows the realization of lasers with very powerful short pu lses following the principle of amplification of long optical pulses l inearly frequency modulated. The compression and expansion factors wit hin reach are of the order of 10(4) to 10(5).