Thermo-optical simulation is a compulsory improvement of classical ray tracing, since many branches of optical and laser technology have to deal with thermal gradients. This paper discusses an approach for coupling FEM and ray tracing simulation tools by processing FE data using scattered data approximation techniques. The implemented interface for two space dimensions is being validated by comparing approximated data to measured values from a CO2 laser application of up to 1.75 kW. Finally, the benefits and further developments of analyzing thermal gradients in optical simulation are being discussed

Thermo-optical simulation is a mandatory enhancement of classical ray tracing, since nowadays many fields in the branch of optical technology have to deal with thermal effects. This paper discusses an approach for coupling the finite element method (FEM) and ray tracing simulation by processing finite element (FE) data using scattered data approximation techniques, particularly with an adaptive weighted least squares approximation algorithm in two dimensions. The validation of the implemented interface is being conducted by comparing approximated data to analytical functions. Finally, FEM data are being processed by the developed algorithm to demonstrate the applicability on appropriate problems.