通过引进等腰棱镜，利用椭偏测量技术实现了液体复折射率的精确测量.基于菲涅尔公式及椭偏测量原理，从理论 上分析仪器测量得到的椭偏参数与棱镜-液体界面椭偏参数的关系，并讨论了测量液体折射率及吸收系数的精度.使用消光式 椭偏仪，测量了水和印度墨水的复折射率，得到了样品的折射率、吸收系数随浓度变化的实验曲线，实验结果与参考文献基本 一致.实验表明: 棱镜椭圆偏振技术测量液体折射率及吸收系数的精度分别为0.000 4 和0.000 3，适合于快速测量.

By introducing isosceles prism，ellipsometry technique is used to measure the complex refraction index. Based on the principle of Fresnel formula and ellipsometry，the relationship between ellipsometric parameters measured by the instrument and ellipsometry parameters of the prism-liquid interface is analyzed theoretically. The precision of measuring the refractive index and the absorption coefficient of the liquid is also discussed. The water and Indian ink are measured by the null ellipsometer，and the experimental curves of the refractive index，the absorption coefficient between the concentration of the samples are obtained. The experimental results are basically consistent with the references. The experimental results show that the accuracy of the prism ellipsometry technique　measuring the refractive index and absorption coefficient of the liquid are 0.0004 and 0.0003，respectively. The prism ellipsometry is suitable for rapid measurement.