MOLD FOR PRODUCING PREFORM FOR POLARIZED WAVE HOLDING TYPE OPTICAL FIBER, AND PRODUCTION OF PREFORM FOR OPTICAL FIBER USING THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain by a melting method a mold, capable of producing a preform having a non-circular, e.g. elliptic, core for polarized wave holding type optical fibers, and to provide a method for producing the preform. ;SOLUTION: This mold 1 is provided with a hollow section 1A having a non-circular, e.g. elliptic, cross-section for producing a preform 10, and hollow section bottom 5 connected with the hollow section 1A at its bottom and having a cross-section larger than that of the hollow section 1A, wherein a clad glass melt 2 is cast into the hollow section 1A, followed by casting a core glass 4 over the clad glass melt 2.;COPYRIGHT: (C)1998,JPO