NIT Strategic Workshop Emerging Technologies for Future Optical and Wireless Networks September 8 & 9, 2003 Nonlinear effects in periodic structures J. Stewart Aitchison Nortel Institute Chair in Emerging Technologies Electrical and Computer Engineering University of Toronto Abstract. Structures with a periodic modulation in refractive index are receiving an increasing amount of experimental and theoretical interest because of their potential to control and manipulate light. In this presentation we will consider their application in nonlinear optics. In particular we will consider the propagation of gap solitons in periodically modulated waveguides. A gap soliton occurs when the nonlinearity locally detunes the stop gap of the material and a pulse of energy can propagate through the structure. More interesting dynamics take place where we include a local defect at the center of the structure. We will describe our recent results using a localized population inversion as a controllable defect and present results on the collisions and trapping of gap solitons. Biography. J. Stewart Aitchison received a B.Sc., with first class honors, and a Ph.D from the Physics Department, Heriot-Watt University, in 1984 and 1987 respectively. His dissertation research was on optical bistability in semiconductor waveguides. From 1988 to 1990 he was a Postdoctoral Member of Technical Staff, at Bellcore, Red Bank N. J. His research interests were in high nonlinearity glasses and spatial optical solitons. He joined the Department of Electronics and Electrical Engineering, University of Glasgow in 1990 and was promoted to a personal chair as Professor of Photonics in 1999. His research was focused on the use of the half band gap nonlinearity of III-V semiconductors for the realization of all-optical switching devices and the study of spatial soliton effects. He also worked on the development of quasi phase matching techniques in III-V semiconductors, monolithic integration, optical rectification, and planar silica technology. His research group developed novel optical biosensors, waveguide lasers and photosensitive direct writing processes based around the use of Flame Hydrolysis Deposited (FHD) silica. In 1996 he was the holder of a Royal Society of Edinburgh Personal Fellowship and carried out research on spatial solitons as a visiting researcher at CREOL, University of Central Florida. In 2001 he became the holder of the Nortel Institute chair in Emerging Technology, in the Department of Electrical and Computer Engineering, at the University of Toronto. He is the author, or coauthor of over 250 refereed journal and conference papers. Prof Aitchison is a Fellow of the Institute of Physics (London), a senior member of IEEE - LEOS and a member of the Optical Society of America. More info: Prof. Aitchison's web site