PURPOSE: To discriminate easily and surely whether the increase of the optical loss of an optical fiber is generated for a long time or not by measuring the loss of the heated optical fiber.
CONSTITUTION: An optical fiber core 3 which is coated with a plastic material and has a length of 50mW2km is stored in an electric furnace 6 so that its roll diameter is 10cmW1m, and this optical fiber core is heated at 100W300°C. In the heating state, the optical loss of the core 3 is measured through a light source 1, a spectroscope 2, a photodetector 4, a data display part 5, etc. On a basis of the loss in the heating tate approximating the loss due to the elapse of a long time, it is discriminated easily and surely whether the increase of the optical loss is generated for a long time or not.
UESUGI SUNAO
KUWABARA TSUNEO
OYAMADA YAHEI
ISHIDA YUKINORI
