Локализованные состояния вблизи тонкого слоя с нелинейными свойствами, разделяющего нелинейные фокусирующие и дефокусирующие среды

Based on the nonlinear Schrödinger equation, new types of localized states near the contact of defocusing and self-focusing media with the Kerr nonlinearity separated by a thin defect layer with the similar nonlinearity have been described. The occurrence of the localized states of two types is demonstrated. The dispersion relations between the excitation localization energy and characteristics of the media and defect layer have been obtained. The localization energy levels for particular cases have been obtained in the explicit analytical form.

Effect of the Substitution of S for Se on the Optical Absorption Spectra of the Glassy Alloys Ag1,6Ga1,6Ge31,2S61,6-xSex

Optical absorption spectra of the glassy alloys Ag1,6Ga1,6Ge31,2S61,6-xSex in the range of 400-1000 nm at 80 and 300 K have been investigated. It was revealed that with increasing of Se the width of the energy gap of the glasses decreases. In samples with x = 13.1, 19.7, 26.2, 32.8, 45.9, 52.5 at 80 K the photoluminescence was observed. It has the vague of peak and half-width emission band ΔE≈0,26-0,30 eV, which is characteristic for the recombination luminescence of the disordered systems. Peculiarities of the optical absorption spectra and photoluminescence are in good correlation with Mott's and Davis' model for localization energy states in the disordered systems.