| 摘要 |
An optical fiber includes a central glass core region comprising maximum refractive index delta percent &Dgr;1, a first inner annular region surrounding said core comprising refractive index delta percent &Dgr;2, a depressed annular region surrounding said inner annular region and comprising &Dgr;3 and a third annular region surrounding the depressed annular region comprising refractive index delta percent &Dgr;4; wherein &Dgr;1MAX>&Dgr;4>&Dgr;2>&Dgr;3. The difference between &Dgr;4 and &Dgr;2 is greater than 0.01 and profile volume, |V3| is at least 60% &Dgr;μm2. |
