Fabrice Mortessagne

Institut de Physique de Nice – Université Côte d’Azur & CNRS

Transport and localization of electromagnetic waves in correlated media

Wave propagation in ordered or disordered media can lead to various transport phenomena depending on the short or long range order present in the structures. Understanding and being able to predict the transport properties in such systems is therefore important from a fundamental point of view, and might be crucial for many different applications. In my talk, I will focus on transport properties in photonic media composed of high index dielectric cylinders in air placed according to (i) stealthy hyperuniform point patterns, in a 2D cavity, and (ii) lattices neither fully ordered, nor disordered, namely aperiodic Vogel spirals, in a cavity of variable height. Measurements are performed in the microwave range (1 to 10 GHz) in finite-size open systems. As a function of the degree of correlation of disorder, a rich “phase diagram” can be built exhibiting band-gaps, transparent or diffusive transport regimes, and different types of localization. Indeed, the deterministic aperiodicity fosters new regime of hampered transport, based on specific localized modes. Unlike their counterparts in disordered media, these modes are remarkably robust to changes in cavity dimensionality.

Related papers:
– Experimental Tuning of Transport Regimes in Hyperuniform Disordered Photonic Materials, G. Aubry et al., PRL 125, 127402 (2020)
– Strong localization of microwaves beyond two dimensions in aperiodic Vogel spirals, L. A. Razo-López et al., PRB 109, 014205 (2024)
– Aperiodicity is more effective than disorder in localizing electromagnetic waves, L. A. Razo-López et al., Opt. Mater. Express 14, 816 (2024)