Contents I. Introduction
Uniform dispersion of nanoparticles in organic materials enables modification of the overall refractive index of the nanocomposites in the range between the indices of nanoparticle and organic materials [1]. Such hybrid materials have been attracting much attention as novel refractive index engineering materials for a wide range of optical applications including planar-gradient index lenses, reflectors, optical-wave guides, optical adhesives, anti-reflection films, holographic information storage devices and optical coupling materials [2]. Of particular importance for those applications is high optical transmittance at the wavelength of interest [1]. However, there is a trade-off between high refractive indices and high transparency. A high particle loading level not only leads to a high refractive index of the hybrid films but also increases light-scattering intensity, leading to low transparency [3].
