You are cordially invited to UNAM Nanocolloquium seminars focusing on advancements in the field of nanoscience and nanotechnology. The seminars bring us the most recent developments in these exciting fields. This week’s talk will be presented by Prof. Stefan Rotter (Vienna University of Technology) Nanocolloquium series
Title: Coherent perfect absorption and transmission of light
Date: May 8, 2024 (Wednesday)
Time and Venue: 11:00 UNAM Conference Hall (SU-01)
Abstract:
In my talk I will present two recent works focused on the perfect absorption and transmission of waves through interferometric cancellation of backscattering. In the first case [1], we demonstrate that even a weakly absorbing film can be turned into a “coherent perfect absorber” by building a degenerate cavity around it. This special cavity perfectly couples incoming light fields with arbitrary wavefronts into the absorber – even for the case that light is a dynamically varying speckle pattern. In the second case [2], we demonstrate how to construct an anti-reflection structure for a complex scattering system like a disordered medium. Similar to an anti-reflection coating for conventional eye-glasses, this structure leads to perfect transmission across the scattering system by suppressing back-scattering for any incoming wavefront. If time permits, I will also say a few words about the topological origin of the above effects and how this aspect can be used to engineer thermal radiation [3].
[2] M. Horodynski, M. Kühmayer, C. Ferise, S. Rotter, and M. Davy, Nature 607, 281 (2022)
[3] M. S. Ergoktas, A. Kecebas, K. Despotelis, S. Soleymani, G. Bakan, A. Kocabas, A. Principi, S. Rotter, S. K. Özdemir, and C. Kocabas, arXiv:2401.08316
Short Bio:
Stefan Rotter is professor at TU Wien’s Institute for Theoretical Physics. After studies in Vienna and Lausanne, he obtained his Ph.D. in 2004, followed by a postdoctoral position at Yale University. His group was established in 2011 and focuses on non-Hermitian physics, theoretical quantum optics and on the propagation of classical or quantum waves through complex media. In all of these fields the Rotter group aims at identifying interesting new research directions and at exploring them in close collaboration with the experiment.