Manufacturable low-crosstalk high-RCMF 13-core 5-LP mode fiber with graded-index core and stairway-index trench

We propose a novel scheme of high doped core and stairway-index trench structure to design a manufacturable graded-index 13-core 5-LP mode fiber with low inter-core crosstalk (ICXT) and large mode differential group delay (MDGD). By using the couple power theory and the finite element method (FEM), the change ICXT of with fiber parameters are investigated. The design of core graded profile and trench structure are optimized to achieve better performance and to meet the fabrication conditions. The numerical result demonstrate that this fiber achieves a low ICXT of lower than -30dB/km (Rb≤500 mm). The bending loss values satisfy the ITU-T recommendation G.655 in 195 µm cladding diameter. Furthermore, the dispersion and the MDGD dependences on wavelength are calculated. The relative core multiplicity factor (RCMF) is obtained as 75.17, which realizes the high density multiplexing. The fabrication methods of this fiber are briefly introduced. The designed fiber may be used for Space-division multiplexing (SDM) system to solve the problem of fiber capacity limitation.