| 摘要 |
PROBLEM TO BE SOLVED: To provide a heating device capable of heating without allowing penetration or diffusion of OH groups, impurities, and the like into a heated body by using plasma flame and a heating method using the same; to provide a heat-resistant dielectric substance, especially a glass body or the like, as a heating object and a method for producing a heat-resistant dielectric substance, a glass body, an optical fiber preform (including an intermediate), and an optical fiber by using the heating device; and to provide an optical fiber preform and an optical fiber, both remarkably reduced in the OH group content. SOLUTION: The heating device and the heating method are made so that a (dried) clean second gas substantially not containing a hydrogen molecule or a hydrogen-atom-containing compound is blown out of the vicinity of a gas for plasma formation. The gas for plasma formation is also made so as not to contain a hydrogen molecule or a hydrogen-atom-containing compound. Preferably, the heating device is installed so as to freely movable relatively to the heating object. The penetration and diffusion of a hydrogen-containing compound or the like can be prevented by intercepting the peripheral atmosphere in the vicinity of plasma flame and also in the region heated to a high temperature in the periphery of a flame contact area. COPYRIGHT: (C)2005,JPO&NCIPI |
