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

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. © 1969 The American Institute of Physics.