Post-compression of femtosecond laser pulses using self-phase modulation: from kilowatts to petawatts in 40 years

The pulse duration at the output of femtosecond lasers is usually close to the Fourier limit, and can be shortened by increasing the spectral width. To this end, use is made of self-phase modulation when a pulse propagates in a medium with cubic nonlinearity. Then, the pulse with a chirp (frequency dependence of the spectrum phase) is compressed due to a linear dispersion element, which introduces a chirp of the same modulus, but opposite in sign. This pulse post-compression, known since the 1960s, has been widely used and is being developed up to the present for pulses with energies from fractions of a nJ to tens of J. The review is devoted to the theoretical foundations of this method, problems of energy scaling, and a discussion of the results of more than 150 experimental studies.