光ファイバの低損失化

抄録

Research and development on optical fiber technology, made in the last decade, has rapidly improved the transmission characteristics, and has succeeded in reducing the attenuation loss to the ultimate limit in silica based optical fibers. Such loss reduction not only acceralates the practical use of the optical fibers for optical transmission media, but also gives detailed data on optical absorption and scattering phenomena.
This paper describes the loss mechanism in optical fibers including the intrinsic and the extrinsic ones, and another intention of this paper is to describe howto minimize the extrinsic losses by the actual fiber fabrication processes. The emphasis is put on the reduction of OH-ions and waveguide imperfections by the Modified Chemical Vapor Deposition (MCVD) and the Vapor-phase Axial Deposition (VAD) method.