E. G. SAUTER, PhD, is a member of the research staff in quantum electronics at the Institute for High Frequency Technique and Quantum Electronics of the University of Karlsruhe, Germany. He has been a visiting professor at the University of Wisconsin and the Academy of Sciences of the USSR. Dr. Sauter received a doctorate in nonlinear oscillations from the University of TA1/4bingen and an advanced degree in quantum electronics from the University of Karlsruhe.