EXPERIMENTAL CONFIRMATION OF SELF-TRAPPING FROM THE DEPENDENCE OF SELF-MODULATION ON PROPAGATION DISTANCE

Abstract

The self‐trapping interpretation of apparent small‐scale filaments has recently been questioned. Experiments were therefore undertaken to test whether the observed filamentary structure is caused by self‐trapping. We found that the filaments propagated over distances of the order of a few centimeters. To confirm this result, the spectral broadening in filaments versus propagation distance was determined. These observations give a nonlinear index change which agrees with the index change calculated from the observed diameter.