Thesis of Rabih El Sokhen

Defense of thesis Rabih El Sokhen - laboratory PhLAM

Information on the organization of this presentation in visio: Possibility to attend it in the amphitheatre.

Abstract :

This thesis presents experimental and numerical investigations into bulk and edge invariants within a 2D synthetic photonic lattice subjected to discrete step walks. The lattice is engineered by time-multiplexing light pulses in two unequal-length optical fiber rings coupled with a variable beam splitter (VBS). In this configuration, one dimension exhibits real-space dynamics, while the other is governed by an external phase modulator (PM). Employing heterodyne detection, we access spectral information and measure eigenvalues and eigenvectors, enabling the extraction of bulk invariants such as Berry curvature and Chern number associated with the photonic bands. Furthermore, we derive an expression for the winding number and demonstrate that the emergence of edge states is tied to specific geometric boundaries. Finally, we highlight the impact of edge topology on the overall system topology, which can either suppress or induce the presence of edge states.

Keywords : Photonic lattices,coupled fiber rings,Discrete step walk,Eigenvalue,Eigenstates,Topological invariants