Statistical Description for Assumption-free Single-shot Measurement of   Femtosecond Laser Pulse Parameters via Two-photon-induced Photocurrents
  Through examining the product of the mathematical variance of intensity with respect to time and frequency, we arrive at a temporal characterization of laser pulses through parameters for pulse duration, group delay dispersion and temporal form. These statistics, which are sufficient to predict subsequent pulse behavior, are recoverable in a simple experiment, measuring the two-photon-induced photocurrents in three nonlinear diodes. With only two photodiodes, we demonstrate that pulse durations as low as several tens of femtoseconds can be easily measured in a single shot if the usual assumptions of pulse form and dispersion are made as in the more difficult autocorrelation setup. 
Eric R. Tkaczyk (CUOS), Sylvain Rivet (LSOL), Lionel Canioni (CPMOH),   St\'ephane Santran (CPMOH), Laurent Sarger (CPMOH)