| 摘要 |
PURPOSE:To reduce the area of a tip opening and to improve considerably the resolution by sharpening the tip of the core of an optical fiber conically by selective etching, applying its surface with a metallic coating, then removing the coating of the conic tip part which is sharpened by plasma etching. CONSTITUTION:The tip of the single-mode germanium-doped silicon optical fiber 5 consisting of a clad 7 whose outward shape is 125 mum and the core 6 whose diameter is 10mum is cut at right angles, then dipped in fluoric acid liquid, so that the tip of the core 6 is sharpened conically. Thus, the core tip which has a 45 deg. angle theta and an about 40 nm radius of curvature is obtained. The pointed tip part of the optical fiber 5 is provided with the coating 8 of gold and chromium and etched in a plasma etching device to form a hole in the conic tip. Thus, a pickup whose tip opening has <=50 nm area is obtained and the resolution is improved greatly. |
