| 摘要 |
PURPOSE:To provide a title silica glass firmly bonded to core base material, having no remaining fine bubbles, and suited to producing optical fibers by a method wherein the surface of clad raw material, etc. is etched with HF to form stripes having 0.1-5mum depth in lengthwise direction. CONSTITUTION:Internal or external side of clad raw material, or internal surface of holder raw material is etched with HF to form stripes 1...1 of 0.1-5mum depth in lengthwise direction so that silica glass tube 2 for producing optical fiber is provided. This glass tube 2 is a silica glass tube for optical fiber which allows production of original rod in which the surface of clad and holder raw material is improved, adhesivity of core and clad material is enhanced, and no remaining fine bubbles exists. By drawing original rod produced from this glass silica tube 2, optical fibers having excellent light transmission properties are obtained without causing cut failures in drawing. |
