OPTICAL FIBER COUPLER AND ITS PRODUCTION

摘要

PURPOSE:To provide an optical fiber coupler which has a high mechanical strength and can be miniaturized and can stand the use in fierce temperature circumstances and is more superior in temperature characteristic. CONSTITUTION:A dopant to control the refractive index is added to cores 1a and 2a or clads 1b and 2b of optical fibers f1 and f2 with a prescribed concn. distribution. The optical coupling part of an optical fiber coupler 10 is formed by welding these optical fibers f1 and f2 in parallel. The concn. distribution of the dopant for the control of the refractive index in this optical coupling part is different from that in the optical fiber parts.