A. A. Galkin Donetsk Institute for Physics and Engineering, National Academy of Sciences, Donetsk, Ukraine:

V. V. Rumyantsev

S. A. Fedorov

We show that the optical characteristics of an imperfect photonic crystal can vary significantly due to the transformation of the photon mode spectrum caused by the presence of impurity layers. The photonic mode spectrum has been studied using the model of imperfect superlattice of a one−dimensional crystal with two elements (layers) in the unit cell: the first layer is silicon, and the second one is the liquid crystal. Peculiarities of the dependence of the lowest band gap on the concentration of randomly embedded admixture layers (including plasma layers) in that system have been studied. The theory developed on the basis of virtual crystal approximation allows carrying out numerical calculations of the concentration dependence of the corresponding optical characteristics. This latter advantage significantly expands the possibilities for simulation of similar composite materials with predetermined properties.

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