本文针对学生在理解激光高方向性与空间相干性联系时存在的困惑，系统分析了普通非相干光源与激光光源在相干性及方向性上的本质差异．通过对比物理光学与激光原理中的空间相干性理论，阐明了二者的区别与内在联系，为学生深入理解激光“四性”提供了理论支撑．

This paper addresses students′ common difficulties in understanding the connection between the high directionality of lasers and their spatial coherence. It systematically analyzes the fundamental differences between conventional incoherent light sources and laser sources in terms of coherence and directional properties. By comparing theories of spatial coherence in physical optics and laser principles, the distinctions and intrinsic relationships between these concepts are clarified, providing theoretical support for students to gain a deeper understanding of the "four key characteristics" of lasers.