薄膜光学常数决定薄膜的光学性能。通过对椭圆偏振仪测试原理的分析，得到求解薄膜光学常数超越方程的数值算法简化公式，并利用MathCAD的“Solve Block”模块开发了基于Windows系统的椭圆偏振测量薄膜光学常数的计算程序，该程序可用于单层有吸收薄膜或无吸收薄膜折射率和厚度的计算。实际应用结果表明，该计算具有数值准确、精度高、运算速度快、适应性好，对系统无特殊要求等优点，可用于薄膜制备过程的在线检测。

The optical constants of thin film are decisive factors for its optical properties. A simplified numeric algorithm expression for solving transcendental equation of optical constants was obtained by analyzing the test principle of ellipsometer. A Microsoft Windows based calculating program for optical constants of thin films with “Solve Block” module of MathCAD by ellipsometer was developed. It can be used to calculate refractive index and thickness of thin films with little absorption or even no absorption as its feature. The results of practical operation indicate that this method has the advantages of better accuracy, high precision, high speed, and universal usage. It can be used in online test with ellipsometer during the process of film preparation.