基于干涉的光学玻璃划痕深度测量

Scratch Depth Measurement of Optical Glass Based on Interference

划痕是光学玻璃常见的缺陷,会导致光束质量下降、光学玻璃热效应增强、抗激光损伤性能降低等,所以在加工过程中需要对其进行准确检测和表征。选取划痕深度值为70 nm的光学玻璃为检测样本,采用光干涉法通过光波加载光学玻璃划痕信息,接着对干涉条纹图像进行图像处理和边缘检测,获取划痕的实际深度值。实验证明,光干涉法测量划痕深度值为70 nm的光学玻璃时,相对误差低于1%。所提方法为光学玻璃加工过程中发现数十纳米级的划痕深度值提供了一种检测手段。

Scratches are commonly found defects in optical glasses,which degrade their beam quality,enhance the thermal effect,and reduce resistance to laser damage.Therefore,accurate detection and characterization of scratches is critical during processing.In this study,an optical glass with a scratch depth of 70 nm was selected as the detection sample.The optical glass scratch information was loaded by light waves using an optical interference method.Then the interference fringe image was processed and edge-detected,and finally the actual scratch depth value was obtained.Experimental results show that the relative error observed for the 70 nm scratch depth of optical glass using optical interferometry is less than 1%.Thus,the proposed method provides a detection method for the scratch depth value in the order of tens of nanometers during optical glass processing.