Mixing rules for group velocities in nanocomposite materials and photonic crystals

Mixing rules for group velocities in nanocomposite materials with different architecture, including lamellarinhomogeneous nanotextures, Maxwell Garnett structures, and one-dimensional photonic crystals, are derived and analyzed. The group velocity can be controlled for such composite structures by changing nanocrystal sizes and varying the dielectric properties and the content of the constituent materials. The interference of scattered waves in structures with a spatial scale of optical inhomogeneities comparable to the radiation wavelength gives rise to new physical phenomena that cannot be described in terms of the effective-medium approximation.