概要介绍椭圆偏振光谱 (SE)的原理与特点 ,并用椭偏光谱测定了一组结晶度不同的无取向PET薄膜的光学常数谱 ,研究半结晶性高聚物PET不同结晶形态对其光学性能的影响 ,发现随结晶度的增加 ,其光学常数显著增大 ,并趋于晶态的光学常数 .光学性质的改变可能与微晶的尺寸有关 The principle and characteristics of ellipsometry (SE) are briefly introduced. The optical constants of a series of non-oriented PET films with different crystallinity are measured by ellipsometry. The effects of different crystalline forms of semicrystalline polymer PET on the optical properties It is found that the optical constants increase significantly as the degree of crystallinity increases, and tend to the optical constants of the crystalline state. The change of optical properties may be related to the crystallite size