| 摘要 |
PURPOSE:To provide an optical fiber excellent in radiation resistant characteristics and having high NA. CONSTITUTION:The objective optical fiber is composed of a core consisting of a GeO2 glass containing at least 300ppm OH group and a clad consisting of a fluorine doped quartz glass. Since GeO2 has high refractive index of 1.61 and a refractive index of the clad is reducible to about 1.44, different in the specific refractive indices between the core and the clad can be made larger, thus optical fiber having high NA is obtained. Further, radiation resistant characteristics is improved by containing OH group in GeO2. |
