中文摘要：

利用惠更斯作图法说明在普通单轴晶体中适当条件下也存在负折射现象，计算了发生负折射的临界人射角，推导了数值计算负折射角的方程．本文的工作有利于在教学中介绍左手材料及负折射现象时，给予学生正确全面的认识．

英文摘要：

The Huygens construction is used to elucidate that the negative refraction phenomenon may occur in the common uniaxial crystals under the appropriate condition. The critical angle of incidence for occurrence negative refraction is calculated and the equation for numerically computing the negative refraction angle is obtained. This is beneficial for the students giving a right overall understanding while the left-handed materials and the negative refraction phenomenon are introduced in the teaching.