物理模型在工程教育中的应用与实践——以光纤光学中“光线轨迹方程”教学为例

Practice and Application of Physical Model in Engineering Education:Taking the Teaching of the Light Trajectory Equation in Optical Fiber Course as an Example

为使学生能更形象、直观、深刻地理解工科专业中的某些知识点,提出利用将学生初次接触的新概念与其已储备知识相联系,特以光纤光学中“光线轨迹方程”为例进行说明。在该课程的教学中,将光线轨迹方程与学生已经熟知的引力方程进行类比,其中,阶跃折射率分布光纤与零重力场相似;渐变折射率分布光纤与地球重力场相似;光线轨迹与质点具有在相应的场下相似的运动状态及性质。从而使学生很容易理解光线在光纤乃至其他类型光波导中的传播轨迹,并解释为什么渐变折射率分布较阶跃型光纤具有更小的色散及更高的信号传输速率。

This paper proposes to link the new concept of students'first contact with their accumulated knowledge.It is important for students to know some knowledge points in engineering major more vividly,intuitively and profoundly.Therefore,the Light Trajectory Equation in Fiber Optics course is taken as an example.The step index distribution fiber is similar to zero gravity field,and the gradient index distribution fiber takes after earth gravity field.The trajectories of light and material particles have similar motion states and properties in corresponding fields.Thus,it is easy for students to understand the propagation path of light in optical fiber and even other types of optical wave-guide,and explain why the graded refractive index distribution has smaller dispersion and higher signal transmission rate than that of step optical fiber.