Electromagnetic transparency and slow light in an isotropic 3D optical metamaterial, due to Fano-like coupling of Mie resonances in excitonic nano-sphere inclusions

► Three dimensional isotropic MTM, composed of spherical excitonic (CuCl) nanoparticles in a dielectric host is introduced in UV regime, which is capable of exhibiting electromagnetic transparency and slow light effects. ► Group indices of refraction on the order of several thousands can be achieved within the transparency windows, around the excitonic resonance of the particles. ► The effect of the non-uniformity in the size distribution of the particles is also studied showing that the effect can be observed even for 10% fluctuation of the particles sizes.