Influences of the drawing conditions on optical characteristics in undoped-silica-core single-mode fibers.

The influences of the drawing conditions on the optical characteristics of undoped-silica-core/fluorine-doped-silicaclad single-mode fibers are investigated. The optical loss depends strongly on the drawing conditions. Moreover, the cutoff shifts to lower wavelengths with an increase in the drawing tension because of the drawing-tension-induced decrease in refractive-index differences.