A Scalar wave equation with an aix direction variate z is used to describe a single-mode taper fiber, and the scalar wave equation is changed to one-order differential equations group by a Simple transform.

• 本文采用含有轴向坐标参变量的标量波动方程来描写锥体光纤,通过一种简单的变换,将标量波动方程化为一阶微分方程组。