Conference Agenda

We present a new microscopic theory for wavefront shaping in complex media, extending the classical radiative transfer framework to describe the coherent propagation of structured waves. This formalism captures, for the first time, the full spatial structure and transmission properties of scattering eigenstates, revealing how their intensity profiles depend on the medium’s geometry. It remains accurate beyond the diffusive regime and naturally incorporates experimental complexities such as absorption and partial channel control. This framework offers powerful tools to understand and manipulate wave transport in complex photonic systems.

Strong Anderson Localization manifests itself as an interference wave phenomenon, potentially leading to completely localized states under infinite extension. We propose a framework for characterizing light transmission through three-dimensional high-refractive amorphous materials, showcasing both localization and photonic band gaps (PBG). Leveraging advanced numerical techniques and recent advancements in Finite-Difference Time Domain (FDTD) simulations, we explore how light behaves in complex dielectric materials and how these effects interact near the bandgap.

State-of-the-art computational methods combined with common idealized structural models provide an incomplete understanding of experimental observations on real nanostructures, since manufacturing introduces unavoidable deviations from the design. We propose to close this knowledge gap by using the real structure of a manufactured nanostructure as input in computations to obtain a realistic comparison with measurements on the same nanostructure. We demonstrate this approach by computing the transmission spectrum based on the structure of a real photonic bandgap crystal, as previously obtained by synchrotron X-ray imaging. This spectrum is complex with among others significant frequency speckle and shrinking of the stopband, which can not be predicted by a Utopian model with perfectly round pores. Our method provides essential insight in the effects of manufacturing deviations on the optical properties of real nanostructures.

Fruitful analogies exist between waves like light or sound that propagate in mesoscopic photonic or phononic metamaterials and the elementary excitations in atomic crystals like phonons, electron and spin waves. A peculiar class of wave transport is discretized transport with hopping in all three dimensions on superlattices, as demonstrated in phonons, electrons and spins, but not yet for light. Here, a superlattice is a periodic arrangement of a supercell that consists itself of multiple unit cells of an underlying crystal structure. In this work, we experimentally observe light waves propagating by hopping between neighbouring cavities along high-symmetry Cartesian directions in space. The hopping transport leads to the appearance of defect bands in the 3D photonic band gap, as theoretically identified by scaling and machine learning methods. Cartesian light is a completely new mode of light propagation (e.g., different from CROWs) that opens the door to a plethora of applications.

This study theoretically demonstrates the use of subwavelength structures to create a metamaterial (MM) for birefringent capping on a one-dimensional photonic crystal (1DPC). The MM-terminated 1DPC can simultaneously support both transverse electric (TE) and magnetic (TM) surface modes within the visible to near-infrared (VIS-NIR) range.