| 摘要 |
PURPOSE:To suit a light guide element to a fiberscope, etc., with excellent separation into the background and picture, by providing a metal-containing silica glass layer, absorbing light of specific wavelength, around a fibrous light transmission line. CONSTITUTION:Individual solid wire f1 in a group of light transmission wires f1-f4 is formed of core 1 consisting essentially of silica and coating layer 2 of sliica with added P2O5 and B2O3 and outside of it, light absorptive leakage-preventive layer 3 having added Ti<3+>, etc., is provided. A fiberscope or the like obtained by bundling this solid wire f1 allows a picture to be seen clearly enough because visible rays are transmitted through solid wires f1-f4, and also allows it to be seen nealry in violet because the existence of Ti<3+> permits the long-wavelength part of visible rays to be absorbed among solid wires f1-f4, so that it can be made clear to discriminate between the background and picture. Further, this leakage-preventive layer 3 adheres well to solid wires f1-f4 and its coefficient of thermal expansion is close to that of coating layer 2, so that it can easily be handled in the process of manufacture. |
