Propagation of a high-intensity laser pulse with small-scale intensity modulation

Abstract

For laser beams of large aperture with power far above the critical power for self-focusing, nonlinear propagation instabilities lead to the growth of small-scale variations in intensity and phase. We report measurements of the growth rate for interference fringes in unpumped ED-2 laser glass as a function of fringe spacing and intensity. Calculations based on the simplest form of linearized small-scale instability theory agree approximately with the measured rates, and a more complete linearized treatment predicts the growth rates within experimental error.