Modern optical systems must satisfy high demands in terms of functionality and performance. With complex optical elements the problems in manufacturing surfaces with sufficiently high quality require new approaches in manufacturing technology. Although the geometrical shape of such structures can be generated by different means, achieving a high surface quality is not always possible for complex surfaces.
A concept for the manufacturing of high quality complex glass surfaces is presented within this publication. The idea is to develop a microwave assisted thermal polishing process supported by CO2-laser radiation. This combination aims to the reduction of thermal gradients in the glass, by heating a definite glass volume during surface treatment using laser radiation. To realise the high surface quality it is absolutely necessary to control the process temperatures. With temperature measurement devices i.e. pyrometers, the average volume temperature is monitored as well as the temperature in the laser spot on the glass surface. By controlling the temperatures of the volume and the temperature on the optical glass surface, it is possible to implement a stress reduced thermal polishing process.
The results of the software based process controlling will be shown by means of CO2-laser polished samples. Additionally the method of process optimisation by analysing the control parameters will be explained and demonstrated. The use of such a system allows the processing of many temperature based laser process applications of amorphous materials. The request for quick polishing processes, independent from the 3D-shape of the surface will be reached by this innovative technique.