Analysis of characteristics of few mode fiber fusion splicing under dynamic spatial mode crosstalk

In this paper, an analytical model of the fusion splicing loss of few-mode fiber (FMF) under the condition of dynamic crosstalk is proposed. Under different dynamic spatial modal crosstalk caused by fusion mismatches and rotation angles, we analyze the variation trend of the fusion splicing loss characteristics of FMF with LP01,LP11a, and LP11b, respectively. Simulation results show that under the condition of axial misalignment introducing modal crosstalk, the splice loss of the LP11a and LP11b modes is higher than that of LP01. On the other hand, the modal crosstalk caused by rotation angles makes the fusion splice loss of LP01 present symmetrical distribution, and the loss of fusion splice of LP01 is maximum at 45°. When rotating from 0° to 90°, for LP11a and LP11b modes, the fusion loss of LP11a decreases gradually, while the loss of LP11b increases gradually. Both are in a symmetrical distribution. Meanwhile, we build an FMF fusion splice loss measurement system based on photon lanterns and FMF circulators. The experimental results show that it is consistent with the simulation results, and the experimental and simulation results confirm the feasibility of the fusion splice fault loss analysis modal under dynamic crosstalk conditions.