Docent seminar in Physics by Katia Gallo Title: Nonlinear Photonic Crystals Abstract: Photonic crystals are materials patterned with periodic dielectric structures. Since they were first proposed, in 1987, they have grown into a burgeoning research field. Nowadays, their engineerable response is already used in a broad range of applications, ranging from telecommunications to biology and sensing. The next step is to achieve ultrafast tunability of such devices, made possible by optical nonlinearities. In this talk, we shall discuss several approaches to combining optical nonlinearities and photonic crystal structures. We shall also see examples of how the technological capability to engineer the quadratic nonlinearity in ferroelectric materials such as lithium niobate can yield a new class of photonic crystals, where the flow of light can be moulded by purely nonlinear mechanisms. Tid: Tisdagen 2010-12-14 kl 14.15 - 15.00 Plats: KTH Albanova, FD5, Roslagstullsbacken 21 Kontakt: Fredrik Laurell