| CPC C03B 37/01446 (2013.01) [C03B 37/01486 (2013.01)] | 6 Claims | 

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               1. A method for manufacturing an optical fiber preform, comprising supporting at least one end of an optical fiber preform with a gripping portion; 
            heating the optical fiber preform while rotating to process the optical fiber preform; and 
                inserting a resiliently crushable buffer material between the gripping portion and the optical fiber preform, wherein 
                the resiliently crushable buffer material includes a resiliently crushable first member in contact with the optical fiber preform and not in contact with the gripping portion, and a resiliently crushable second member in contact with the gripping portion and not in contact with the optical fiber preform, 
                a composition of the resiliently crushable first member in contact with the optical fiber preform is different from a composition of the resiliently crushable second member in contact with the gripping portion, 
                the resiliently crushable first member in contact with the optical fiber preform does not contain CaCO3, 
                the resiliently crushable second member in contact with the gripping portion does contain CaCO3, and 
                the resiliently crushable first member in contact with the optical fiber preform contains PFA. 
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