采用近场显微成像法测量了高功率激光镜片薄膜表面裂纹和内部节瘤缺陷,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原子力显微镜(AFM)图像和扫描近场光学显微镜(SNOM)图像,以便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,这导致薄膜的表面呈层状断裂,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;此外,SNOM图中的亮斑表明,薄膜的内部有高于基底折射率的节瘤存在。 Near-field microscopic imaging was used to measure the surface cracks and internal nodular defects of high-power laser lens films. The mechanism of their formation was also analyzed. The 100 nm-diameter conical tip radiation evanescent wave interacts with the embedded defects in the film. The evanescent wave is converted into a radiant wave and then collected by the objective lens and imaged point by point in the far field. The atomic force microscope (AFM) images and scanning near-field optical microscope (SNOM) images to intuitively identify the physical mechanism by which defects are generated. The results show that the surface cracks of the film and the internal nodules can be accurately and simultaneously identified in the effective area of ​​evanescent wave. By comparing the results of SNOM and AFM, it is found that the residual stress on the substrate surface cracks accumulates during the coating process, which leads to the surface layer lamellar fracture, the single transverse cross-sectional size of the smallest cracks is 165nm, which surpasses the experimental accuracy of traditional far-field detection In addition, bright spots in the SNOM map indicate that there is a nodule inside the film that has a higher refractive index than the substrate.