Angelo Angelini
Polytechnic of Turin, Italy
Title: Photon management assisted by surface waves on an all-dielectric platform
Biography
Biography: Angelo Angelini
Abstract
An overview of recent results on photon management through surface modes on purely dielectric multilayers is provided. Diffraction as well as guidance and confinement of Bloch Surface Waves (BSW) are shown, and a particular focus on near-field coupling of emitters with BSW modes is provided. The ability of modifying the radiation pattern of emitters by employing nano structured surfaces is gaining growing attention in a variety of applications related to nanophotonics, such as few-molecule and quantum emitters detection. In this framework, Surface Plasmon Coupled Emission (SPCE) has demonstrated to be an effective way to address this issue. Generally, plasmonic-based mechanisms exploit a near-field transfer of energy from the emitters to plasmonic modes. However, the main drawback in using plasmons on metal is represented by ohmic losses, producing broad resonances and absorption of useful signal. An effect similar to SPCE occurs on properly tailored one dimensional photonic crystals sustaining BSWs. Due to the very low absorption coefficient of the 1DCP materials, the BSW-coupled fluorescence can propagate for longer distances as compared to plasmons. In addition, the use of dielectric structures offers interesting advantages such as a wide spectral tunability (from UV to IR); the possibility to have either TE or TM polarized BSW and higher Q-factors. By properly structuring the surface of 1DPC, light coupled to BSWs can be manipulated in several ways (e.g. diffracted, guided, and focused). In particular, spontaneous emission of emitters lying on the surface of 1DPC can be efficiently beamed out in arbitrary directions with low divergence.
