Graduate School in Nonlinear Science

Sponsored by the Danish Research Academy

Role of the Critical Collapse Singularity in forming and sustaining Nonlinear Waveguides in Air

by J.V. Moloney
Arizona Center for Mathematical Sciences
University of Arizona, Tucson

Tuesday, June 30, 1998 14:00 h
at MIDIT, Building 305 room 027

MIDIT-seminar No. 410

Abstract: High power femtosecond duration laser pulses can undergo critical collapse while propagating in air. Two distinct physical mechanisns can arrest the formation of the critical collapse singularity. Weak normal group velocity dispersion may cause the laser pulse to split in two with the posibility of further collapse and splittings. Alternatively a weak plasma filament can form and limit the explosive intensity growth. This weak dissipation causes the collapsing filament to decay. However the background reservoir of energy, not contained in the collapsing filament, can feed subsequent collapses leading to a novel dynamic waveguiding effect.