| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical fiber with a large effective area and a small bend loss.SOLUTION: An optical fiber comprises a glass core 20 and glass cladding 200, and the cladding 200 comprises a first annular region 30, a second annular region 50, and a third annular region 60. The core 20 has a maximum relative refractive index relative to the third annular region 60 greater than about 0.1% and less than about 0.3%. The first annular region 30 has a relative refractive index less than about 0.025%. The second annular region 50 has a negative relative refractive index. The second annular region 50 includes silica based glass with at least 10 closed randomly dispersed holes situated therein, and the mean distance between the holes is less than 5000 nm, and at least 80% of the holes have a maximum cross-sectional dimension less than 1000 nm. |
