Kazuo Koya

Optical fiber coupler and method for preparing same

Rare earth element-doped multiple-core optical fiber, method for fabricating the same, and optical amplifier using the same

Rare earth element-doped multiple-core optical fiber and method for fabricating the same

Method for the preparation of a dehydrated quartz glass material for light transmission

Method for preparing a fused silica glass body co-doped with a rare earth element and aluminum

Quartz glass-made optical fibers and a method for the preparation thereof

Supporting member for optical fiber coupler

Optical amplifier with erbium-doped fiber

Grating optical fiber, and optical fiber base material suitable for grating

Base material of optical fibers and a method for the preparation thereof