ИСТИНА

Pendellösung effect is the periodic variation of the diffracted beams intensity. It was predicted by the dynamical diffraction theory for the X-ray diffraction. It was experimentally observed for the X-ray, neutron and microwave diffraction. In 2006 it was observed in optical range for the diffraction of light in 3-dimetsional opal photonic crystals. This effect can be used to obtain negative-index materials, for optical switching, Recently the pendellösung effect in one-dimensional photonic crystal at Laue geometry was predicted. The considered crystal consists of periodically alternating dielectric layers of two types. The pendellösung effect is caused by the formation of two spatial modes called borrmann and antiborrmann in a crystal and each of these modes is localized in layers of its own type. The periodic exchange of energy between these modes occurs. We present the numerical simulation and the experimental observation of this effect in the porous silicon photonic crystal.