Adaptive control of pulse phase in a chirped-pulse amplifier

Using experimental feedback, we demonstrate that a chirped-pulse amplifier can adaptively learn to compensate for the higher-order phase dispersion that is inherent in the amplification process. A genetic algorithm-based search routine is used to repetitively update the pulse phase in a programmable pulse stretcher during a plasma breakdown experiment to maximize the magnitude of spectral blueshift. Reductions in pulse duration from 37 to 30 fs and substantially better wing structure are typically obtained as a result of the optimization.