Thermo-optical analysis of the radial-symmetric plane-parallel plate.

Predicting aberrations due to heating of optical components often requires complex models combining optics, opto-mechanics, and thermo-mechanics. This complicates taking thermo-optical effects into account early in the design. This work is part of a project to find design rules and scaling laws to simplify conceptual choices early in the design. Aberrations are caused by thermal expansion and change of refractive index due to temperature and stress. Modelling of wavefront error requires combination of finite element methods with raytracing, including many variables for material properties, geometry, and heat transfer. Substantial complexity is the result. For a plane-parallel plate, parameter analysis is used to merge many of these variables into groups. This reduces model complexity and improves the understanding of underlying mechanisms. The thermal model is then analyzed with regular numerical solver techniques and resulting temperature fields are used to estimate wavefront error. The results agree with more complex finite element and ray-tracing methods. A future goal is to use the model as starting point for derivation of design laws for optimal thermo-optical behavior. 18 lbildung und Simulation T Henning Rehn