Evolving FROGS: phase retrieval from frequency-resolved optical gating measurements by use of genetic algorithms

We present a new technique based on genetic algorithms for retrieving the e lectric field and the phase of ultrashort pulses from frequency-resolved op tical gating (FROG) traces. We have successfully applied a very basic genet ic algorithm to the two most common beam geometries: polarization gate and second-harmonic generation (SHG). In the case of SHG FROG, the genetic algo rithm returns a lower error than the standard iterative composite algorithm .