Characterization Group

  • Highly-precise determination of optical losses

  • Laser radiation resistance of air- and space-borne optical components

  • Analysis of coating defects down to the nm range

  • International standardization of measurement methods for the qualification of optical components


The Characterization Group specializes in examining and qualifying optics for a wide application field, for example in laser material processing, semiconductor lithography, aerospace technology, and also for fundamental research. The core competencies of this group are the highly-precise determination of the slightest optical losses, or determination of the laser-induced damage threshold. A focal point of research activities also lies on the identification and characterization of layer defects, which determine the life-span and power compatibility of laser optics, especially for UV and high power applications. However, work in this group is not limited to the development of new measurement techniques and sensor technology. Fundamental physical mechanisms of the interaction of such defects with electromagnetic radiation are also examined.

For these activities, a variety of analysis techniques are available:

  • Spectral broadband absorption measurement using laser calorimetry from the VUV to the IR spectral range
  • Measurement of the laser-induced damage threshold down to the 5th harmonic of the Nd:YAG laser
  • High sensitivity measurement of angle-resolved and total scattering down to the ppm range
  • EUV/XUV spectrophotometry
  • Fluorescence spectroscopy
  • Standardized environmental tests for aerospace applications

These measurement techniques, which have been tested and established by the work group, are constantly being further developed and improved according to the requirements from different industrial branches, and according to customer requirements, for the implementation of new technologies.

The continual further development and improvement of the measurement technology is, however, only one aspect. Rapid advancements in the optical industry in the past few years have shown that modern optical components are partially far ahead of the standardized testing procedures. The working group is thus also very active in the field of international standardization, in order to adapt the current requirements to the state-of-the-art of technology.