| 摘要 |
<p>PURPOSE:To widen a detecting range of detecting light, and also to reduce an optical propagation loss in an optical transmission line by providing a long- sized photodetecting member formed by glass to which Md<3+> and Sm<3+> have been added. CONSTITUTION:A long-sized photodetecting member 9 formed in a shape of a rod or in a shape of a fiber by glass to which Nd<3+> and Sm<3+> have been added is provided in front of a photodetecting end 4a of an optical fiber for forming an optical transmission line, and an end part 9a is coupled to the photodetecting end 4a of the optical fiber 4 through an optical coupling part 10. As a result, discharge lights 6, 7 are made incident from the peripheral surface of the member 9, and converted to long wavelength light by the glass to which Nd<3+> and Sm<3+> have been added, for forming the member 9. Also, the long wavelength light which has propagated through the member 9 is radiat ed from the end face 9a, propagates through the inside of the optical fiber 4, and reaches a photodetecting means 5. In this way, the detecting range of detecting light can be widened.</p> |
