| 摘要 |
PURPOSE: A single mode optical fiber is provided to reduce the portion of a fluorine-doped inner cladding depressed in the substrate tube without the increase of leakage loss of LP01 mode and the degradation of the other propagation characteristics of an optical fiber, thereby reducing manufacturing cost with increased capacity. CONSTITUTION: A single mode optical fiber comprises from center to periphery: a core having a radius(a) and an index difference(Dn 1) with outer cladding(Dn cl) comprised between -0.5.10^-3 and 0.5.10^-3; an inner depressed cladding having a radius(r ring1) and an index difference(Dn inner) with outer cladding; a ring having an inner radius(r ring1) comprised between 21μm and 35μm, an outer radius(r ring2) and an index difference(Dn ring) with the outer cladding comprised between -0.5.10^-3 and 0.5.10^-3;-an outer depressed cladding having a radius(r out) and an index difference(Dn out) with outer cladding. The fiber has a ratio of the volume of the core over the width of the ring(W ring) comprised between 0.12μm and 0.2μm and the outer depressed cladding has a volume comprised between 15μm^2 and 30μm^2. [Reference numerals] (AA) MCVD or PCVD; (BB) Substrate tube; (CC) Down-doped jacket type tube; (DD) Diameter of fiber (um) |
