Optical simulation of colloidal photonic crystals with controllable size spheres of silica Anis Chaouachi, Chtourou Radhouane, Adel M’nif and Ahmed Hichem Hamzaoui Eur. Phys. J. Appl. Phys., 67 3 (2014) 30501 Published online: 20 August 2014 DOI: 10.1051/epjap/2014140079