| 摘要 |
PROBLEM TO BE SOLVED: To provide a fiber for optical amplification whose diameter is so thin that it is possible to miniaturize optical amplifiers, while the fiber has a large mode-field diameter, lower connection loss with a second optical fiber than an allowable value, and small bending loss. SOLUTION: The fiber for optical amplification has an 60-100μm outer diameter of its open wire 1, and a 1.6-2.7% relative refractive-index difference between a core and a clad, and the core 2 or the core 2 together with a part of the clad 3 is doped with a rare-earth element such as erbium. The fiber has a coating layer composed of one or two layers, and bending loss at 1,620 nm wavelength is 0.2 dB/m or lower when bent with a diameter of 20 mm. In the fiber having a coating layer of two layers, it is preferable that the outer diameter of the primary coating layer 4 is 90-160μm, while the outer diameter of the secondary coating layer 5 is 110-210μm. In the case of one layer, it is preferable that the outer diameter of the coating layer is 90-160μm. COPYRIGHT: (C)2004,JPO&NCIPI |
