Optical aging behaviour naturally induced on As2S3 microstructured optical fibres

The efficiency and the stability of As2S3 microstructured optical fibres (MOFs) are limited by the shift of their optical properties that occurs over time due to a naturally induced aging process. Such sensitivity becomes more crucial for long optical path. Among the variety of fibre designs, the MOFs are developed for promising photonics applications such as supercontinuum generation for example. In the present work, we carried out an extensive aging study on As2S3 chalcogenide MOFs in ambient atmosphere. The evolution of the fibre transmission spectrum has been studied with regards to exposure time. The analysis of the transmission line profile was performed in terms of different spectral components Gaussian in shape and the infrared absorption bands have been attributed to the corresponding chemical groups' vibration modes or overtones. The time-dependent evolution of fibre attenuation has been studied as well as its longitudinal evolution for a given exposure time. Previous knowledge of extinction coefficient inherent to vibration components allows to predict their corresponding concentration. The content of hydroxyl groups tightly bonded to the glass network of the sulphide MOF core decreases exponentially with distance away from the MOF extremity. The report results show that a deleterious aging effect occurs over the first hours and days of exposure. This have crucial implications for storage and employment techniques and requires holes airproofing technique. (C) 2014 Optical Society of America