本文研究了一种类锥形梯度折射率纤维的光线传播特性和近轴成象规律。光在这种类锥形纤维中的传播具有变幅值和变周期的振荡特征,文中从光线轨迹的近似解析式出发,导出高斯光学公式,并讨论了结果的适用性。研究表明,类锥形梯度折射率纤维与在光学特性上锥形梯度折射率纤维十分类似,它们都可望成为微型光学和激光装置的重要新元件。 In this paper, we study the light propagation characteristics and paraxial imaging of a tapered gradient index fiber. The propagation of light in this kind of tapered fiber has the characteristics of variable amplitude and periodic oscillation. According to the approximate analytic formula of ray tracing, the Gaussian optical formula is deduced and the applicability of the result is discussed. Studies have shown that pyramidal graded-index fibers are very similar to pyramidal-graded-index fibers in optical properties and are expected to become important new elements in micro-optics and laser devices.