光纤通讯中,模变换直接影响带宽和功率的模间分布。在光纤传感中,模变换还对干涉条纹有很大影响。因此,对模类型及模变换系数的研究是非常重要的。理论和实验表明,模变换主要来源于光纤结构不均匀以及内应力、外部压力、弯曲等。为了改变 In the optical fiber communication, the mode change affects the distribution of the bandwidth and power directly. In fiber optic sensing, mode switching also has a significant effect on interference fringes. Therefore, it is very important to study the type and modulo transform coefficient. Theoretical and experimental results show that the mode change mainly comes from the uneven structure of fiber and internal stress, external pressure, bending and so on. To change