OPTICAL FIBER

摘要

PURPOSE:To provide an optical fiber with which an increase in the loss of a long wavelength is small at a low cost by using a core consisting of SiO2-GeO2-F and a clad whose inside layer part consists of SiO2-F and whose outside layer part consists of SiO2-B2O3 to constitute the optical fiber. CONSTITUTION:The clad 3 consisting of the inside layer part 3a which consists of SiO2-F contg. F at 0.05-1mol% concn. and is in proximity to the core 2 consisting of SiO2-GeO2-F contg. GeO2 at 3-20mol% concn. and F at 0.05-1mol% and the outside layer part 3b which contains B2O3 at 0.05-6mol% concn. is provided to the outside periphery of the core 2. The effect of preventing the formation of an OH group near the core owing to the hydrogen diffusion from the outside of the optical fiber is thus made large and the optical fiber which is free from the influence of the formation of the OH group by hydrogen for a long period of time is obtd. without the influence of the IR absorption loss at >=1.3mum wavelength and with the small transmission loss.