
Prof. Leonard Kahn's research has spanned several areas. His early work involved the study of the surfaces of solids. Specifically, he studied the chemisorption of alkalis on metal surfaces. The technique that was used was the density functional formalism. He used this formalism to study hydrogen in metals, as well as defects in metals. The main thrust of the work was to calculate the electric field gradient in these imperfect materials. His attention then changed to the study of the optical properties of one dimensional conductors, such as TTFTCNQ. These calculations led to the investigation of acoustic plasmons in one dimensional conductors. He then tackled the problem of superconductivity in the A15 materials, looking for an alternative mechanism to explain their high temperature transition. In the late 80's, Prof. Kahn became interested in nonlinear phenomena. This began as an interest in chaos and "strange attractors." With Ken Hartt, he developed some techniques for determining whether or not two sets of time series are dependent on common variables. While at Irvine, he noticed that the equations being used to describe nonlinear optics were very similar to those he had seen in studies of chaos. It turns out that very simple models contain a wealth of phenomena. This model of nonlinear optics is a useful platform for studying solitonic resonances, the temporal and spatial development of chaos, signal processing, and electron selftrapping. Prof. Kahn's interest in nonlinear optics continues. Specifically, he is examining layered structures to determine how electrical devices, such as diodes and transistors can be modeled by optical systems. He has had two seniors complete their senior research papers on this topic, as well as a Ph.D. thesis by Kelan Huang on nonlinear optics. Most currently, he is examining the effects of defects in the layered structure on the transmission properties of the system. Senior Project: Optical transmission through multilayers with nonlinear response 