Parametric downconversion has for many years been a major testing ground in studies of basic concepts of quantum theory. This talk will focus on some recent investigations probing aspects of complementarity in both spontaneous and stimulated parametric downconversion, and on the role of vacuum fields in the modeling of experiments performed at the University of Potsdam (Germany). Recent observations of transverse spatial properties of single photon fields generated in spontaneous downconversion will be described and shown to be well explained by a theoretical model that takes into account the fiber-coupled photodetection and the degree of spatial coherence implied by the van Cittert-Zernike theorem.

Dr. Milonni graduated summa cum laude from Niagara University in 1969 with a B.S. in physics. He then commenced graduate studies, where he completed a Ph.D. in theoretical physics in 1974. He was a research physicist at the Air Force Weapons Laboratory (1974-1977), a senior staff engineer at the Perkin-Elmer Corporation (1977-1980), and a professor of physics at the University of Arkansas (1980-1985) before becoming at staff member (1985-2005) and a laboratory fellow (since 1994) in the Theoretical Division of the Los Alamos National Laboratory. He is currently a guest scientist at Los Alamos and a Research Professor of Physics at the University of Rochester. Dr. Milonni’s primary research interests have been in quantum optics and electrodynamics, especially in connection with the quantum and fluctuation properties of electromagnetic radiation. In addition to many research papers, he has authored several books, including Lasers (1988, with J.H. Eberly); The Quantum Vacuum. An Introduction to Quantum Electrodynamics (1994); Fast Light, Slow Light, and Left-Handed Light (2005); and Laser Physics (2010, with J. H. Eberly). Dr. Milonni was awarded the 2008 Max Born Award by the Optical Society of America "for exceptional contributions to the fields of theoretical optics, laser physics and quantum mechanics, and for dissemination of scientific knowledge through authorship of a series of outstanding books".