Coherent NuSENSOR pure silica core single-mode fibers are immune to the damaging effects of hydrogen ingression, enabling Brillouin, Rayleigh and FBG based distributed temperature and strain sensing in harsh environments. These 0.12 NA fibers are optimized for operation at both 1310nm and 1550nm. NuSENSOR single-mode fibers provide tight tolerance optical and geometrical specifications measured at the application critical wavelengths. The fibers come with either a polyimide or a mid-temperature acrylate coating and are also available with a hermetic carbon layer. For high H2 partial pressure and elevated temperature up to 300°C, you will find no measurable induced loss for typical sensing applications.