Research on a novel mode division multiplexer with low crosstalk, low loss and few mode ring-core transmission channel

Abstract

A novel mode division multiplexer with low loss, low crosstalk is proposed for a type of few mode ring-core fiber (FM-RCF) in our paper. A novel FM-RCF with pure silica ring-core and larger effective refractive index difference (>1×10−3) between the modes is proposed as mode transmission channel of our multiplexer. The ring-core channel structure and the larger effective refractive index difference (>1×10−3) between the modes are used to effectively reduce the mode crosstalk and improve the mode extinction ratio. Pure silica ring-core is employed to effectively reduce the transmission attenuation and splicing loss. The (de)multiplexing of LP01, LP11a and LP11b modes for FM-RCF is realized. In this paper, the performance of mode division multiplexer is studied by using the beam propagation method and finite element method. The coupling efficiency and extinction ratio of the mode division multiplexer is better than −7.83 dB and 28.13 dB in the range of 1400 nm–1700 nm. The coupling efficiency of the mode division multiplexer is better than −1.39 dB in C band, which is better than −1.69 dB in the previous reference. The extinction ratio of the LP01 mode is more than 48.13 dB in the C band, which is 11.76 dB higher than the average extinction ratio of LP11 mode. The extinction ratios of the three modes are better than 35.42 dB, which is 15.42 dB higher than those of the modes in the previous reference. The intrinsic losses of few mode ring-core transmission channels are all 0.154 dB/km at 1.54μm.