The monitoring of the furnace chamber and the material to be heated under the influence of high temperatures imposes special demands for the employed imaging optics. Conventional components, which are usually equipped with a front aperture of several cm² in size, cannot be used because they cannot withstand the high temperatures (up to 1500 °C) and also have a negative influence on the temperature distribution in the furnace due to heat conduction. New types of optical components made of temperature-resistant materials enable the design of optical systems within the framework of keyhole diagnostics, which at the same time reduces heat flow, is temperature-stable and can record a variety of signals (thermal imaging, 3D acquisition, etc.).
In the sub-project, an optical sensor is being developed as a keyhole diagnostic device that provides high resolution in harsh environmental conditions while requiring little space. This sensor will be able to work autonomously as well as being a part of a more complex autonomous sensor module. To realize the sensor concept, complex optical components are required, which are manufactured from new temperature-resistant materials using additive manufacturing processes. Besides the most comprehensive imaging of the furnace interior possible, 3D imaging or thermal imaging are to be realized.