3D sub-wavelength refractive index adjusted metal oxides for applications in optical sensing

Abstract

We present a refractive index engineering scheme for functional metal oxides (SnO2, ZnO, TiO2) by the method of sub-wavelength engineering on the 10-50nm scale for applications in optical sensing. The method employed is based on templating by a triblock copolymer Pluronic F-127 for the manufacture of controllable 3D sub-wavelength nanostructures. By this method we demonstrate that the refractive indices of functional metal oxides can be altered substantially from their nominal value of ≥ 2 to be as low as 1.25.