METHOD FOR PRODUCING RARE EARTH-ADDED OPTICAL FIBER PREFORM AND RARE EARTH-ADDED OPTICAL FIBER

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a rare earth-added optical fiber preform capable of stably adding a rare earth element at a high concentration, and to provide a rare earth-added optical fiber produced by the production method.;SOLUTION: The method for producing a rare earth-added optical fiber preform comprises forming a core soot 21 by either a VAD (vapor axial deposition) method or an OVD (outside vapor deposition) method and then adding a rare earth element 22 in a gas phase to the core soot 21, wherein a first heat zone for generating a gas containing a rare earth element and a second heat zone for heating the core soot are provided, and the heat zones are each independently temperature-controlled to produce the rare earth-added optical fiber preform.;COPYRIGHT: (C)2006,JPO&NCIPI