On the mechanism of non-linear optical attenuation at 1.3-1.5 mu m in arsenic sulfide and tellurium oxide glasses

The mechanism of optical non-resonant non-linear refraction and absorption/ attenuation in glasses at 1.3-1.5 mum is of interest for efficient all-opti cal switching in optical fibre telecommunications. We discuss the mechanism of nonresonant non-linear attenuation (loss) at 1.3-1.5 mum in glasses wit h the largest linear refractive indices, such as As2S3- and TeO2-based glas ses. These glasses are transparent and possess the largest non-resonant non -linear refraction at 1.3-1.5 mum to date (up to 10(-14) cm(2)/W), allow si ngle-mode fiberization and therefore are suitable for all-optical fibre swi tching. We show that with a single beam Z-scan technique we identify the co ntribution of small-angle non-linear scattering to the total non-linear att enuation at 1.3-1.5 mum. We show that small-angle non-linear scattering doe s contribute to the non-linear attenuation at such irradiances at which non -linear absorption is not present yet. (C) 2001 Elsevier Science B.V. All r ights reserved.