HIGH-PURITY ALUMINUM COATED FIBER AND ITS PRODUCTION

摘要

PURPOSE:To decrease the transmission loss of an aluminum coated fiber by providing a coating layer consisting of a aluminum having >=99.999% purity on an optical fiber. CONSTITUTION:The optical fiber 2 is an optical fiber consisting of quartz glass, etc. having an excellent transmission characteristic and the coating layer 2 consisting of the aluminum is formed on the outside surface of the optical fiber 2. High-purity aluminum having >=99.999% purity is selected as the material for forming the coating layer 3 and the film thickness of the coating layer 3 is specified in an about 15-35mum range. The layer is too thin to protect the optical fiber 2 if the thickness is <15mum. Then an inconvenience such as the easy increase of the transmission by external force arises. The layer is too thick and the effect of protecting the optical fiber 2 is not longer improved and such is uneconomical if the thickness exceeds 35mum. In addition, an inconvenience such as the failure in decreasing the loss of the optical fiber 2 by the stress exerted to the coating layer 3 arises.