Analysis of characteristics of few-mode fiber fusion splicing under dynamic spatial modecrosstalk

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,LP₁₁, and LP₁₁, respectively. Simulation results show that under the condition of axial misalignment introducing modal crosstalk, the splice loss of the LP₁₁ and LP₁₁ 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 LP₁₁ and LP₁₁ modes, the fusion loss of LP₁₁ decreases gradually, while the loss of LP₁₁ 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.