| 摘要 |
<p>In a process for manufacturing a multiple fiber comprising a plurality of mutually fused optical fibers composed of a core made of pure quartz glass and a clad layer made of dopant-containing quartz glass and provided on the core by bundling a plurality of corresponding optical fiber preforms and wiring the bundle at an elevated temperature, three-layered optical fiber preforms having a support layer composed of quartz glass capable of being wired at least at 1800oC on the clad layer are used as the preforms and a bundle of the preforms is wired to obtain a multiple fiber wherein the support layer of the optical fiber has a thickness of 0.01 to 1 ν. This multiple fiber is useful as an image guide for observing inside of a high-temperature furnace or a nuclear reactor.</p> |
