费马原理在球面界面理想成像中的应用——主轴外物点

Application of Fermat's principle in ideal imaging at the spherical boundary for the object point outside the principal axis

费马原理是几何光学的一个基本原理.其物理意义是:光在空间中实际传播路径是以光程取极值的路径传播.本文给出了运用费马原理直接推导得到主轴外物点的球面反射和球面折射的实际光线方程的新方法,并使用近轴条件得到了相应的物像公式.

Fermat＇s principle is a basic one in the geometrical optics,which means that the actual trajectory in the space depends on the extremum of the optical path.Based on the Fermat＇s principle,a new method is proposed to get directly the equation for the practical optical path in reflections and refractions at spherical boundary for the object point outside the principal axis,and then the object-image formula is also derived in the condition of axial ray and axial object.