Effects of low temperature and hot steam on reliability of specialty optical fibers designed for avionics applications

Miscellaneous avionics applications of optical fibers require their use at extreme temperatures and harsh environments. It is important that fiber properties, including optical attenuation and mechanical strength are immune to the environment conditions. Exposing specialty optical fibers to extreme conditions and testing their properties during and after the exposures helps in optimizing the fiber designs for specific applications. In this work, optical fibers with different refractive index profiles and different coatings were immersed in liquid nitrogen (LN₂) and hot steam and their main properties were analyzed.