基于膜层结构的弛豫现象，建立了一个多晶膜的应力演化模型，并通过线性组合给出了复合膜的生长应力模型。利用双光束基底曲率测量装置实时测量了电子束蒸发氧化铪、氧化硅多晶膜及其复合膜的应力演化过程，并对测量结果进行了拟合分析。

The evolution of stress in evaporated SiO₂, used as optical coatings, is investigated experimentally through in situ stress measurement. A typical evolution pattern consisting of five subprocedures (thin film deposition, stopping deposition, cooling, venting the vacuum chamber, and exposing coated optics to the atmosphere) is put forward. Further investigations into the subprocedures reveal their features. During the deposition stage, the stresses are usually compressive and reach a stable state when the deposited film is thicker than 100 nm. An increment of compressive stress value is observed with the decrease of residual gas pressure or deposition rate. A very low stress of -20 MPa is formed in SiO₂ films deposited at 3×10^-2 Pa. After deposition, the stress increases slightly in the compressive direction and is subject to the stabilization in subsequent tens of minutes. In the process of venting and exposure, the compressive component increases rapidly with the admission of room air and then reaches saturation, followed by a logarithmic decrement of the compressive state in the succeeding hours. An initial discussion of these behaviors is given.