High dispersion four-mode fiber for mode-division multiplexing systems

This paper presents a novel dispersions equalization technique for multilayer core four-mode fiber using LP mode-matrix method. Each of the core ring radius of the alternating center-high (CH) and center-low (CL) index profile was optimized to a specific thickness value. The core ring radius varied in each case to determine the optimized thickness (OPT) for thn e dispersions equalization. The OPT of the center high index core fiber (CH) denoted by R-1, R-2, and R-3 were found to be 4.25 mu m, 2.6 mu m, and 2.3 mu m, respectively. Similarly, an OPT of the center low index core fiber (CL) which was denoted by X-1, X-2, X-3, and X-4 was found to be 2.0 mu m, 3.0 mu m, 4.20 mu m and 1.60 mu m, respectively. At 1.55 mu m wavelength, these values were used to model the two fibers to achieve an equalized modal dispersion. It is the first time, to our knowledge, a core-ring radius of a CH, and CL index profile varied to a certain OPT value to achieve dispersion equalization. Fabrication challenges were also discussed in this paper.