SINGLE MODE OPTICAL FIBER

摘要

PURPOSE: To obtain a single mode optical fiber which is good in both of dispersion characteristics and bending loss characteristic by providing the refractive index profile of a core part with a gentle recess and specifying the difference in the specific refractive index of the recess to a specific value or below. CONSTITUTION: The refractive index profile of the core part 1 of the single mode optical fiber of a 1.3μm band having the refractive index profile of a step type in which the refractive index n1 of the core part 1 is higher than the refractive index n2 of the clad part 2 has the gentle recess and the recess is <=2.0% in the difference in the specific refractive index. Such difference is based on a theoretical simulation and if the difference in the specific refractive index of such recess is confined to <=0.2%, the single mode optical fiber good in both of the dispersion characteristic and the bending loss characteristic is obtd. The reason why the difference in the specific refractive index of the recess is confined to <=0.2% lies in that the dispersion at the same Q value (the same bending loss) is not improved as compared with the conventional case where there is no recess if the size of the recess increases 0.2%.