Mode coupling analysis of trench assisted FM-MCFs with heterogeneous inner cladding for OSDM links

The data traffic increases about 40 % per year around the globe and the demand for the bandwidth will further increase in the near future. It is estimated that the necessary data capacity per fiber may surpass the limit of the current single mode fiber capacity and the use of multi core fiber is thought to be the advantageous approach to manage this capacity crunch. As the number of spatial channels that can be supported in a multicore fiber is decided by the core to core spacing and the number of modes supported in each core for a fixed outer cladding diameter, few mode multicore fiber becomes the most suitable solution. This paper presents the design and analysis of trench assisted little mode multicore fiber with various heterogeneous inner cladding structure. Coupling coefficient of the modes is analyzed for various inner cladding and trench parameters using COMSOL Multi physics software. Based on the simulation results it is observed that, FM-MCF with heterogeneity in trench and depressed inner cladding refractive index difference promises a lower coupling tendency than FM-MCF with homogeneous trench and inner cladding refractive index difference.