Tuesday June 28, 2005
4 PM - 5:30 PM
ENG Z-50 Auditorium

Office Hours:
Wednesday June 29, 2005
3:30 PM - 4:30 PM
ENG B-16

"Energy conservation and the optical theorem"
Prof. P. Scott Carney
University of Illinois at Urbana-Champaign

The conservation of energy in wave fields leads to a remarkable result known as the optical theorem, the cross-section theorem, or sometimes the unitarity relation. We will discuss some recent generalizations of the theorem to fields with complex momenta (inhomogeneous fields) and arbitrary incident fields. Further, we will consider lossy scattering objects which give rise to non-unitary systems. The basic mathematical approach will be covered with emphasis on physical interpretation. A recently developed imaging modality based on the measurement of extinguished power as an alternative to standard holography will be presented with experimental results. A poster by one of the junior participants, D. R. Lytle II, will cover the experiment in more detail.