Research Of Super-resolution Laser Differential Confocal Pore Size Measurement

Micropore structure is widely used in cutting-edge scientific fields of optical microscopy, polymer chemistry, materials science and biomedicine,and micropore size as a key parameter directly determines the pore performance. Therefore, the precise measurement method for pore diameter is required seriously. For the issue of micropore size measurement, this paper proposes a new measurement technology of super-resolution laser differential confocal pore diameter, combined with differential confocal scanning laser imaging technology, the super-resolution image processing and contour edge criterion to achieve pore diameter size of convenient, non-contact precision measurement and provide a feasible way to solve the problem of micropore size measurement.Laser differential confocal technology with the unique axial light intensity response characteristic implements the fixed-focus measuring of the micropore samples to obtain three-dimensional morphology contour map of the micropore structure. And using filtering algorithm and super-resolution image restoration algorithm to achieve a smooth and edge sharpening process for the three-dimensional contour map, offers support for the micropore size measurement. Then, the micopore forming simulation based on the three-dimensional point spread function of the laser differential confocal optical path acquires the connection between the edge intensity of contour map and micropore diameter, and finally the criterion of micropore edge intensity corresponding this relationship can be used to the processed three-dimensional image to get the micropore measurement result. Lastly, the comparison measurements with the result of Olympus microscope verify that the resolution of proposed method is superior the 200 nm.The subject is supported by National Instrumentation Program "Laser differential confocal measurement instrument development and application research"(No.2011YQ040136). The main contents of the paper include:(1)Research and summaries of the application in the field of frontier science of optical microscopy, polymer chemistry, materials science and biomedicine, features and drawbacks of the existed measurement methods, and exposition of the research objectives.Briefly presentation of the imaging principle of the laser differential confocal laser microscopy and image super-resolution algorithm, and establishment of the theoretical model for the micropore measurement providing a theoretical basis for the subsequent measurements analysis(2)Application of the micropore structure property and the three-dimensional point spread function of laser differential confocal optical path to simulate, and calculation of the relationship between the criterion of micropore edge and its diameter.(3)Design and alignment of the laser differential confocal sensors, the experimental research with these sensors, and the vertification of the validity of this method by comparison test with Olympus microscope.