Spectroscopic ellipsometry on opaline photonic crystals

In the present paper, the optical and structural properties of an opaline photonic crystal consisting of a closest packing of nanospheres have been studied via spectroscopic ellipsometry. This method allows for a non-destructive determination of the effective refractive index without any assumption on material properties. Further we are able to gather information about the structural constitution of the opal by introducing a multi-layer model. The layer distance and the maximum size of the nanospheres can be extracted