of the Performance in Comparison with Experimental Results

Abstract High power diode pumped solid state lasers are attractive sources for various applications in material processing. One of the advantages of diode pumping of solid state lasers is the higher brilliance (maximumoutput power I poorest beam parameter product using equal plan-plane resonators) compared to arc lamppumped solid state lasers.The solid state laser we report on is a side pumped Nd:YAG rod laser. Ten pump modules each consisting of 13 diode lasers, are arranged in a ten fold symmetry. The pump radiation is concentrated into thediffuse reflecting cavity by non imaging optics. For designing the non imaging optics a ray tracing modelwas developed to calculate the distribution of absorbed pump power. In order to get a nearly aberrationfree thermal lensing it is important to get smooth formed pump power.To examine the aberrations influence on output power and beam quality we have set up a model that includes all physical aspects relevant in the high power region. Temperature and stress inside the rod are computed with the help of finite element program using the raytracing results. Temperature and stress distribution in the Nd:YAG rod are used to describe the thermallensing and birefringence of the rod with a two dimensional complex field of Jones matrices. The Jonesmatrices are used by an optical simulation program to compute beam propagation within and outside the