Specific features of polarization anisotropy in optical reflection and transmission of colloidal photonic crystals

This paper reports on the measurements (in linearly polarized light) of the transmission and reflection spectra of colloidal photonic crystals with three-dimensional and one-two-dimensional photonic band structure, i.e., opal films and Langmuir-Blodgett crystals with a refractive index contrast of ∼1.5: 1.0. It has been shown that the polarization anisotropy is enhanced considerably in the diffraction resonance range both in transmitted and reflected light, and that the anisotropy in the resonance range can be as high as 99%. The interaction of photonic crystal eigenmodes has been found to affect the polarization anisotropy. The assumption has been made that the coincidence of the maxima in polarization anisotropy of the resonant and nonresonant light reflection in colloidal crystals originates from the disorder in their lattices. The generality of the results obtained is confirmed by the fact that the polarization anisotropy manifests itself in the same way in colloidal crystals with different lattice symmetries.