EMMANUEL DESURVIRE is Associate Professor of Electrical Engineering at Columbia University. For four years he was a member of the technical staff at AT&T Laboratories which did pioneering work in erbium-doped fiber amplifiers. In 1993 Dr. Desurvire received the IEEE’s Distinguished Lecturer Award. In 1994, he joined Alcatel-Alsthom Recherche in France. He is a contributor to the book Fiber Lasers and Amplifiers and is the author or coauthor of more than 90 technical papers. He received his Diploma of Advanced Studies in the field of theoretical physics from the University of Paris in 1981 and his PhD in physics from the University of Nice two years later. He spent two years in postdoctoral research at Stanford University.