Professor Nikolaos Efremidis, Tenured Assistant Professor, Department of Applied Mathematics, University of Crete and member of Archimedes Center for Modeling, Analysis & Computation, is visiting the Faculty of Physics and Astronomy as an Abbe School of Photonics Visiting Professor in October 2012. During his stay he will give two lectures.
Professor Nikolaos Efremidis
Nikolaos K. Efremidis (NKE) is currently as Assistant Professor in the Department of Applied Mathematics, University of Crete. He obtained his Bachelors degree from the Department of Physics, University of Crete in 1996, and his Ph.D. from the Department of Electrical and Computer Engineering, National Technical University of Athens in 2001. He then worked as a Postdoctoral Fellow at Lehigh University, Department of Electrical and Computer Engineering (2001-2002), at
College of Optics and Photonics, University of Central Florida (2002-2004), and at the Department of Electrical and Computer Engineering, National Technical University of Athens (2005-2006). Since 2007 he joined the Department of Applied Mathematics, University of Crete as an Assistant Professor.
NKE research interests include the study of linear and nonlinear wave phenomena in optics and photonics and their potential applications, as well as solitons, and mathematical modeling, using analytical and numerical methods. His research activity over the last 10 years has led to the publication of more than 50 papers on international refereed journals, over 70 contributions at international conferences, including more than 15 invited presentations. His papers include contributions in the fields of linear and nonlinear optical wave propagation in periodic structures as well as in the area of curved light dynamics.
Curving and focusing light at will
We discuss about the possibilities of curving and focusing light and its applications in optics. By phase manipulation of a light beam we can generate pre-engineered arbitrary convex trajectories. For radially-symmetric optical fields such a behavior gives rise to a new family of waves with an abrupt focus: initially their maximum intensity remains almost constant during propagation, while close to a particular focal point, they suddenly autofocus and, as a result, their peak intensity increases by orders of magnitude. We show how such beams can be generated directly or in the Fourier space and discuss its applications in different settings such as particle manipulation and ablation. We also analyze curved beams propagation in periodic configurations such as waveguide arrays. The multi-band structure of the system can be utilized to manipulate light. Finally, we theoretically propose an extended light-focus structure that follows arbitrary trajectories (that are not necessarily convex). These ray cones have circular bases on the input plane, thus their interference results in a Bessel-like transverse field profile that propagates along the specified trajectory with a remarkably invariant main lobe.
Date: 24.10.2012, 10:30 am
Place: Seminar room IAP