Modelling and Measurement of Electronically Tunable Photonic Crystals

This paper presents details of the modelling that has been used to extract particle spacing from measured diffraction patterns in tunable photonic crystal structures. The photonic crystals are formed from colloidal suspensions of latex spheres with the application of rotating Alternating Current (AC) electric fields. The particle spacing can be rapidly changed by altering the amplitude of the AC field. Initially simple ID diffraction grating theory is used to extract the particle spacing. This is followed by Finite Element (FE) modelling which shows good agreement with the simple theory. Full 3D modelling was investigated but only small number of spheres could be modelled.