GLASS FIBER FOR OPTICAL COMMUNICATION

PURPOSE:To provide a fiber for optical communication which is usable stably without degrading characteristics even under exposure to neutrons by using quartz glass as a core and cladding quartz glass incorporated with a specific dopant thereon. CONSTITUTION:Pure quartz glass is used as a core and quartz glass incorporated with only the boron ( B) of 11 mass number as a dopant is used as a clad. A protective glass layer is formed on the outside circumference thereof. Then, even if the glass fiber is used under exposure to neutrons, the fiber is free from degradation in mechanical strength and increase in light loss, and lends itself stably to optical communication. Since the evolution of heat by the nuclear transformation effect by absorption of neutrons is obviated, the inside parts of nuclear reactors and nuclear fusion reactors are viewed directly with good safety by forming the bundle of the glass fiber.