Core-shell TiO 2 @Silica nanoparticles for light confinement

Abstract Anderson localization is one of the most interesting phenomena in solid-state physics. Particularly, localization of light is an open research frontier which, besides being a fundamental topic it also could present significant applications. In this paper, we report several experimental evidences of localization of light in a colloidal suspension composed of core-shell nanoparticles (TiO 2 @Silica) in ethanol solution. We demonstrate the crossover from a diffusive transport to a localization transition regime as nanoparticle concentration is increased. A striking phenomenon of enhanced absorption arises at localization transition, from which an increase of refractive index close to input border is proposed. Localization of light in liquid suspension opens new avenues in the photonics field, ranging from the designing and manufacture of novel photochemical reactors, powerful sensing tools and other advanced photonic devices, to investigations into fundamental topics, such as the light quantum nature and other phenomena involving photon interactions.