中文摘要：

采用近场显微成像法测量了高功率激光负载镜片薄膜表面裂纹和节瘤缺陷,并分析了它们的形成机制。100nm 孔径的圆锥形针尖辐射的倏逝波与薄膜中预埋的缺陷相互作用，将倏逝波转化为辐射波后，由物镜收集并在远场逐点成像,同步地获得薄膜表面的 AFM 图像和 SNOM 图像，进而直观地识别缺陷产生的物理机制。结果表明：在倏逝波的有效作用区域内，薄膜表面裂纹与内部节瘤可以同时精确地被识别。通过对比SNOM 与 AFM 结果，发现基底表面裂纹在镀膜过程中积累了残余应力，并导致薄膜的表面裂纹呈层状断裂的特征，其单条最小裂纹横向剖面尺寸为 165nm，超过了传统远场检测的实验检测精度；同时，SNOM 图中的光亮斑表明，薄膜的内部有高于基底折射率的节瘤存在。基于此研究可以为分析高功率激光负载薄膜制备过程中缺陷产生的机制提供重要的研究思路。

英文摘要：

The surface flaws and internal knots in a film of high power laser lens are experimentally measured by using a near field micro-image method, and their formation mechanisms are analyzed as well. The evanescent waves radiated by a conic tip at a 100 nm diameter interact with the defects embedded in the films. After the evanescent waves are converted into radiation waves, they are collected by the objective lens and imaged point by point in the far field. Atomic force microscopy （AFM） images and scanning near-field optical microscopy （SNOM） images on the surface of the thin film are obtained synchronously, so as to visually identify the physical mechanisms of the defects formation. The results show that the surface flaw and the internal knot in thin film are accurately identified at the same time in effective interacting areas of evanescent wave. By comparing AFM result with SNOM result, we find that the surface flaw of substrate accumulates the residual stress in the processing of coating, which results in a layered cracking on the surface of film. The crosswise profile scale of single minimum flaw is 165 nm, which is beyond experimental detection precision of traditional far field detection. In addition, the high hot spot in SNOM graph shows that refractive index of knots exist in the thin film is higher than that in substrate.