Random optical media based on hybrid organic-inorganic nanowires: Multiple scattering, field localization, and light diffusion

Random optical media (ROM) are a novel class of photonic materials characterized by a disordered assembly of the elementary constituents (such as particles, wires and fibers), that determines unique scattering, absorption and emission properties. The propagation of light in ROM is affected by the size and optical properties (refractive index, absorption and emission wavelengths) of their components, as well as by the overall 3-dimensional architecture. So far, most of the investigated ROM have been realized using liquid dispersions or bulk samples embedding colloidal nanoparticles or porous systems. While nanowire-based ROM are poorly investigated, such materials can feature new optical effects related to the elongated shape of their building blocks and to their light-transport properties. Here we report on the fabrication and on the morphological and spectroscopic characterization of hybrid organic-inorganic nanowires, realized by doping polymers with dielectric nanoparticles. We investigate light diffusion and multi-scattering properties of 3-dimensional ROM formed by organic and hybrid nanowires, as well as field localization in 2-dimensional networks. The influence of nanowire geometry and composition on the scattering properties is also discussed.