Nonlinear compression of ultra-high-power laser pulses

Nowadays the peak power of PW lasers is limited by the damage threshold of optical compressor diffraction gratings. A promising way to overcome the difficulty and increase peak power is to use an additional pulse shortening after optical compressor without significant energy loses. The discussed method is called CafCA - Compression after Compressor Approach. CafCA possesses three undisputed merits: simplicity and low cost, negligible pulse energy loss, and applicability to any high-power lasers without changing their optical schemes. The key idea of the approach is to broaden spectrum of powerful laser pulses exactly after grating compressor and correct spectral phase with help of reflected dispersion devices (chirped mirrors in particular). The idea has been known since the end of 1960s but its application to lasers with a peak power higher 1 TW has been restricted by a number of physical reasons. The reasons and ways of its overcoming are discussed in the paper. We analyze the recent experimental results that demonstrate the CafCA efficiency in the range up to 200 TW.