Characterization of arbitrarily polarized ultrashort pulses using frequency-resolved optical gating

We discuss two alternative solutions to the ultrashort pulse characterization problem. A numerical study is developed comparing their performance when facing the amplitude and phase retrieval of arbitrarily polarized pulses. Both algorithms are based on Frequency Resolved Optical Gating (FROG) with the use of Second Harmonic Generation (SHG) and the method of Generalized Projections. One of them allows to characterize both components of the pulse after transforming it into a linearly-polarized double pulse while the other one makes possible to retrieve directly the full amplitude and phase evolution of two unknown components (BLIND FROG). We conclude, after some numerical testing, that both algorithms allow an accurate retrieval, even in presence of noise, in a reasonably short computing time.