Alexandru PopaAlexandru Popa received a Physicist Engineer degree at the Polytechnic University of Bucharest in 1966, a Master of Science degree from the University of California, Berkeley, in 1972, and a Ph.D. from the Polytechnic University of Bucharest in 1974.He was a Senior Researcher at the Laser Department, National Institute for Laser, Plasma and Radiation Physics, Institute of Atomic Physics, Bucharest. Since 2016 he has been retired but still works in the field of physical systems modeling. Among his achievements, over a period of more than 50 years, are a connection between quantum equations and classical equations of physical systems, a wave model for atomic and molecular systems, whose accuracy is comparable to the accuracy of the standard Hartree–Fock model and accurate models of relativistic and ultra-relativistic interactions between laser beams and electrons. The wave model is extended to new fields such as molecular biology and the generation of electromagnetic waves and very short pulses in the attosecond domain. Read More Read Less