HIGH-STRENGTH OPTICAL FIBER OF QUARTZ GLASS SYSTEM AND PRODUCTION THEREOF

摘要

PURPOSE:To increase the refractive index of a surface strengthening layer higher than the refractive index of a clad and to eliminate the propagation of multimodes by drawing a perform under the drawing tension under which the refractive index of the strengthening layer attains the refractive index equal to or higher than the refractive index of the clad. CONSTITUTION:Fluorine is doped into the surface strengthening layer of the high-strength fiber of a quartz system consisting of the core/clad/surface strengthening layer to lower the softening temp. to the temp. lower than the softening temp. of the clad and to allow compressive stresses to remain so that the refractive index is equal to or higher than the refractive index of the clad. The transmission characteristic of this fiber is not the propagation to accompany the multimodes but the perfect single mode in this way and the propagation of the multimodes is eliminated. The breaking strength which compares favorably with the breaking strength of the conventional high-strength fibers is obtd.