Abstract

We demonstrate a simple method, based on blind deconvolution, for simultaneously measuring two arbitrary ultrashort laser pulses. The method is a variation of the well-known frequency-resolved optical gating (FROG) technique, and which we call “double-blind” FROG because it measures the two unknown pulses by simultaneously measuring two FROG spectrograms, but obtained from a single apparatus. It retrieves both pulses robustly by using a slightly modified FROG/blind-deconvolution algorithm. Using the polarization-gating FROG beam geometry, we simulate it using very complex pulses and demonstrate it using simple ultrashort pulses from a Ti:Sapphire laser. We find that double-blind FROG has no nontrivial ambiguities and works well.

© 2011 Optical Society of America