Conference Agenda

In this presentation, an open source Quasi Normal Mode (QNM) solver based on Finite Elements will be presented. In typical cases encountered in photonics with dispersive materials and open geometries, computing the QNMs reduces to solving a Non Linear Eigenvalue Problem (NEP). Various linearization schemes will be detailed, as well as several intrinsic pitfalls of the method. Then, a QNM expansion onto the QNMs set will be introduced based on the Keldysh theorem. Finally, the resulting open source template model packaging all the features introduced will be presented.

We propose a simple theoretical model based on the coupled-mode theory which allows to calculate the spectral properties and transmittance of the one-dimensional waveguide structures. The model was verified on the common coupled-waveguide array in which the existence of the symmetry-protected bound state in the continuum (BIC) was confirmed experimentally by Plotnik et al.[Phys.Rev.Letters 107, 28-31(2011)]. The method can be extended to topologically nontrivial lattices to explore the properties of the BICs protected by time-reversal symmetry (TRS).

An advanced hyperspectral sensing imaging taking advantage of engineered all-dielectric platforms supporting bound states in the continuum (BIC) here is discussed. This approach combines surface-enhanced fluorescence and refractometric sensing both based on high-Q resonances in proximity of BICs.To demonstrate the real implementation of the proposed BIC-enhanced imaging as a platform for biosensing, hyperspectral maps of prostate cancer cells are experimentally reconstructed.

An intensively studied quasiparticle in plasmonics is the localized surface plasmon, a collective oscillation of conduction electrons in metallic nanoparticles. Exploring how its resonance frequency changes depending on the nanoparticle geometry is a fundamental task of the field. Inspired by recent groundbreaking experiments, we derive, using a continuum mechanics model borrowed from nuclear physics, analytical expressions for the dipolar plasmon resonances in cylindrical nanoparticles. Importantly, our analytic theory is valid for any aspect ratio of the cylinder, and as such is of relevance for a wide range of experiments.