METHOD FOR MANUFACTURING PREFORM FOR HOLEY OPTICAL FIBER

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a preform for a holey optical fiber wherein an air hole forming substance can be removed without giving a shock to a dried gel when the preform for the holey optical fiber is manufactured by a gel-gel forming method. SOLUTION: A mold is used in the method for manufacturing the preform for the holey optical fiber. The method comprises (a) a step wherein a plurality of elongate tubes expanded or constricted by controlling the inside pressure of the tubes are located in the mold with a predetermined arrangement and expanded, (b) a step of pouring a sol in the mold and make it to be gel, (c) a step wherein the gel is taken out from the mold and that an elongate air hole is formed in the gel by constricting the tubes and (d) a step of removing the tubes. COPYRIGHT: (C)2005,JPO&NCIPI