中文摘要：

根据单层薄膜透射率的表达式，提出了一种用透射法测量薄膜折射率的新方法。按照该方法，通过测量P光和S光在相同入射角下的透射率，可以计算得到薄膜的折射率。在测量中考虑了影响测量结果的两个方面，从而减少了实验误差。在波长为532nm的激光照射下，采用该法测得MgF2薄膜的折射率为1．379±O．005，相对误差小于0．49／6。

英文摘要：

Based on the expression of transmittance of single thin film, we provided a new way to measure refractive index of single thin film. According to the method, the transmittance of the p-polarized light and the s-polarized light was measured at the same angle, then worked out the solution of the refractive index. At the experiment, two aspects which influenced the measuring result had been considered, consequently reduced the experimental error. It was found out that the refraction index of MgF2 thin film was 1. 379 ±0. 005 at the wavelength of 532nm, and the relative error was less than 0.4%.