| 摘要 |
PROBLEM TO BE SOLVED: To provide a lens-attached optical fiber which eliminates problems due to reflected light or return light against a light source and which minimizes coupling loss. SOLUTION: The device is an optical fiber 4 with a lens 1 formed at the end; the lens 1 is constituted of two inclined surfaces 2a, 2b that gradually come close to each other towards the tip end of the optical fiber and a tip end surface 3 that intersects these inclines surfaces; and the device is characteristically such that the tip end surface 3 does not cross at right angles to the optical axis Z of the optical fiber 4 and that, if the tip end surface 3 is curved, the angle is 6-15 deg. between the surface 3 and the plane orthogonally crossing the optical axis of the optical fiber 4. |
