| 摘要 |
PROBLEM TO BE SOLVED: To provide a S-mode optical fiber having a structure capable of efficiently suppressing the increase of a distribution slope. SOLUTION: An optical core 100 is composed of an inside core 110 and an outside core 120, and also an optical clad 200 is composed of an inside clad 210 and an outside clad 220 where sagging is caused. In a cross section orthogonal to the waveguide direction of a signal light, the optical fiber is designed so as to satisfy a relationship: 0<S1/S2<=0.3 where a surface integral value of a specific refraction index difference of the optical clad 200 to the outside clad 220 having an average refractive index n0 is S1 and the surface integral value of the specific refraction index difference of the optical core 100 is S2. In this configuration, it is possible to suppress the increase of the distribution slope due to the sagging inevitably caused in a manufacturing process. |
