Thermo-Optical (TOP) analysis of transmissive elements for laser systems

Increasing laser beam qualities make thermal lensing again a hot topic and demand for a thermo-optical simulation for improving classical ray tracing and enabling optimization possibilities for thermally aberrated optical systems. This paper summarizes the approach for coupling FEM and ray tracing using a weighted least squares approximation algorithm and demonstrates the abilities of the coupled simulation in the case of a CO2 laser system for polishing of glass and plastics. It can be demonstrated that the algorithm can be used for the analysis of higher order aberrations, since the application contains a Gaussian to top-hat conversion lens group which suffers from thermal gradients. Finally, the benefits and further developments of analyzing thermal gradients in optical simulation are being discussed.