Michael Vollmer received his PhD degree for the studies of clusters on surfaces, and his ha-bilitation on optical properties of metal clusters from the University of Heidelberg, Germany. Later assignments were with the University of Kassel, Germany, the university of California in Berkeley, USA, as well as with various institutions in the United States and Asia during sabbaticals. His research interests include atmospheric optics, spectroscopy, infrared thermal imaging, and the didactics of physics. Professor Vollmer has authored one science book and co-authored a scienti� c monograph and about 140 scienti� c papers. Klaus-Peter Möllmann received his PhD from the Humboldt University of Berlin, Germany, studying strongly doped narrow band semiconductors at low temperatures and later, for his habilitation, MCT photo detectors. He subsequently held positions with the Humboldt Uni-versity and with several businesses in industry. Professor Möllmann's research interests include MEMS technology, infrared thermal imaging, and spectroscopy. He is the co-author of about 100 scienti� c and didactical papers.

Both authors are professors of experimental physics at the University of Applied Sciences in Brandenburg, Germany.