利用几何光学来解释模式耦合和漏泄,已推算了多模阶跃型光纤的传输函数。光沅可采用轴对称型的(LED)或线形的(半导体激光器)。用线光沅可允许纤维轴有径向位移。对耦合2KM 长度的六数值孔径纤维(NA=0.475)来说,计算结果表明:线光沅的径向位移和漏泄光对长度短于200M 的纤维是有影响的。纤维长度直 Using geometrical optics to account for mode coupling and leakage, the transfer function for multi-mode step-type fibers has been deduced. Optical Yuan can be axisymmetric (LED) or linear (semiconductor laser). The use of a linear optical element allows radial displacement of the fiber axis. For the coupling of six numerical aperture fibers (NA = 0.475) with a length of 2KM, the calculation results show that the radial displacement and the leakage light of the linear optical elements have an effect on the fiber length shorter than 200M. Straight fiber length