METHOD OF AND APPARATUS FOR EXPANDING MODE FIELD DIAMETER OF OPTICAL FIBER

摘要

PROBLEM TO BE SOLVED: To provide a method of and an apparatus for expanding the mode field diameter of an optical fiber which a specified resion of the optical fiber can be heated with a uniform or desired temperature distribution in heating the optical fiber for forming a TEC (thermally expanded core). SOLUTION: In this method of thermally diffusing dopant attached to a core part and expanding the mode field diameter of the optical fiber by heating the optical fiber 1 with a burner 11, the burner 11 has a heating surface 11a in which a plurality of gas-issuing holes 12 are arranged in the axial direction of the optical fiber 1. The plurality of gas-issuing holes are arranged in a plurality of rows parallelly with the axial direction of the optical fiber and are heated. COPYRIGHT: (C)2004,JPO