| 摘要 |
The invention concerns a multimode optical fiber, with an ct-profile graded-index core with an a-value between 1.96 and 2.05 and a N value defined as N= (R1/λ)2(n1 2-n0 2) between 7 and 52, where R1 is the multimode core radius, n1 is the maximum index of the multimode core and n0 is the minimum index at the outer edge of the graded index core. According to the invention, a depressed region directly surrounds the graded/ index core and satisfies the criteria: -2.20 < Dn2 < 0, where Dn2 is the index difference of depressed region with external cladding, and 220 Ln(N)-1100 < V2 < 220Ln(N)-865, where V2 is the volume of the depressed region. Such a multimode fiber shows an increased OFL-bandwidth above 10000Hz.km at an operating wavelength between 950nm and 1310nm. |
