Steady-state theory of optical striations

An analysis is made of a steady-state theory of a striated plasma column of a long laser spark. Modulation solutions of the steady-state problem are found and their stability is investigated. An approximate analysis and the results of numerical modeling, are used to formulate general conditions for the existence of metastable optical striations. In general, states with spatial temperature oscillations having the largest possible amplitude are found to be the longest-lived. A numerical solution of the problem is obtained for a laser spark in air. If dust particles are present in the air, each of these may become a striation nucleus; in this case, the striation distribution will be random.