Subsurface Defect Detection Technology Of Optical Components Based On Quantum Dot Marking

With the wide application of optical components in many fields,higher requirements are put forward for the surface and subsurface quality of optical components,especially in high-tech fields such as high-energy laser devices and large optical systems,where the requirements for performance ind icators such as stability,resistance to laser damage thresholds and imaging quality are more stringent,and subsurface defects can greatly reduce these performance indicators and cause irreparable consequences for the entire optical system.Depth detection is one of the difficult aspects of subface defect detection.Existing methods achieve depth detection mainly through laminar scanning,which is inefficient.To achieve rapid non-destructive detection of subsurface defect depth of optical components,this paper proposes a technique for detecting subsurface defect depth of optical components based on quantum dot markers by enhancing the subsurface fluorescence signal based on fluorescence microscopy,combined with the laser triangulation measurement principle.The main elements of the study are as follows:(1)This paper investigates the technique of subsurface defect depth detection of optical components based on quantitative measurement by triangulation,combining the high fluorescence efficiency and small size of quantum dots,which enables efficient marking of subsurface defects in optical components.The principle of quantum dot marking of subsurface defects in optical components and the principle of quantitative measurement of subsurface defect depth by combining the triangulation method are described in detail,based on which a subsurface defect depth detection system for optical components is constructed.(2)According to the relative properties of fluorescence and quantum dots,the fluorescent quantum dots suitable for the detection system are determined.Through the mechanism of material removal and the formation mechanism of subsurface defects in the grinding and polishing process of optical components,the interaction force model between quantum dots and the surface of optical components is constructed to analyze the process adaptability of quantum dots marking subsurface defects,and the feasibility of quantum dots marking subsurface defects is verified by experiments.(3)Based on the design of the detection system and the selection of experimental devices,a fluorescent microscopy and triangulation device for measuring subsurface defects of optical components based on quantum dot labelling is constructed.Firstly,standard samples labelled by quantum dots with subsurface defect depths in the range of50 μm to 75 μm were prepared using optical adhesives;then,obtain the subsurface defects detection images of the standard samples through the experimental device;finally,based on the sub-pixel edge detection algorithm,an subsurface defect depth is obtained.The experimental results show that the quantum dot marking can effectively realize the depth measurement of the sub-surface defect of the optical element.The quantum dot marker-based subsurface defect detection technique for optical components studied in this paper achieves subsurface defect depth detection,proposes a new detection method for quantitative measurement of subface defect depth of optical components,and provides a new idea for quant itative removal of subsurface defects in the field of precision machining to provide key parameters.