Modeling of multilayer ultrathin-film photonic crystals for selective filters

The aim of the work was to study the optical properties of the one-dimensional photonic crystals from ultrathin alternating layers of titanium and silicon oxides with different order of alternating layers to form defective half-wave layers in the bulk of the photonic crystal. The layer thicknesses were optimized by the dispersion of the refractive index and it was shown that for the formation of 16-layer photonic crystal structure without a half-wave layer with a photonic band gap in the UV region, it is necessary to use layers of titanium dioxide and silicon oxide with a thickness of 28.3 and 53.2 nm, respectively. The structure of the 26-layer photonic crystal with a thickness of 2130 nm with two non-equidistant half-wave layers forming resonant transmission bands in the photonic band gap with peaks at 550 and 601 nm is proposed. Due to the dispersion of the refractive index, the ratio of the thicknesses of TiO2:SiO2 layers varies from 1:1.88 in the case of a 16-layer structure with a photonic band gap in the UV region to 1:1.5 in the case of a 26-layer structure with a photonic band gap in the visible range . The effect of a photonic crystal structure without half-wave layers on the emission spectrum of a liquid crystal display manufactured using IPS technology has been demonstrated in order to reduce the intensity of the blue component to increase the safety of the user's vision. The using of the photonic crystals with two half-wave defective layers allows to achieve complete separation of the spectrum components, which can be used to modify the spectra of large liquid crystal panels, their manufacture using AMOLED technology is a very difficult technological task even for leaders in this field.