Abstract:For the mode division multiplexing characteristic, a four-mode fiber suitable for mode division multiplexing was designed. By analyzing the relationship of different Δn (refractive index difference between core and cladding) with the effective area, effective refractive index, microbending loss and dispersion, the appropriate Δn value of 0.96% is determined. Simulations were performed on the pattern characteristics of the few-mode fiber and its main parameters were given. Comparisons with the parameters presented in existing literatures show that, the designed four-mode fibers obtain effective area of more than 120μm2 and loss of less than 0.2dB/km, which is suitable for mode division multiplexing.