以纯水为研究对象,利用激光测量了其反射率,并利用菲涅耳公式对反射率进行了计算。比较反射率的计算值和实测值发现有明显的偏离(偏离相对值为8.317%)。对此进行了误差分析,排除这种偏离是主要由试验和计算误差引起的可能性(这些误差累积不会超过1.083%)。利用带消光系数的反射率菲涅耳公式进行修正计算,反射率计算结果与实测值很接近。说明并非只有金属等物质在进行反射率计算时需考虑能量吸收的问题,对于完全符合菲涅尔公式适用条件的纯水来说,在进行反射率计算时同样需引入修正系数。

The reflection index R of water is measured with laser. The calculated reflection index Rp of water is obtained with the Fresnel formula. The relative deviation between R and Rp is 8.317%. Analysis indicates that the sum of the experimental error and the calculation error is less than 1.083%. So this deviation is not mainly caused by the experimental and calculation errors. The Fresnel formula with extinction coefficient is used to calculate the reflection index of water, and the calculated value is very close to the experimental value. It is concluded that the reflection index of water should be calculated with the revised Fresnel formula.