Study For The System Of Optics In Parallel Confocal Measurement Based Astigmatism

Because of the advantages of high accuracy, high resolution and the unique ability of axial tomography, the technology of confocal microscopy finds its application in the fields of semiconductor, microelectronics devices, information storage, engineering surface measurement, medical testing, as well as life science research. In recent years, the parallel confocal technology draws the interests of scholars around the world. Extensive researches by applying this technology have yielded results. However, because of restrictions on the optical system, the parallel distinguishing ability of the system has not been enhanced effectively and the existing axial and radial detection capability can not meet the basic requirements of detection for the three-dimensional micro-structures. Based on astigmatism, the thesis makes an exploration into the parallel confocal detection method. The modulation of astigmatic mirror is used to convert the identification of central focus based on the intensity of light to the one that is based on shapes, with the purpose of improving the detecting ability of the system.Firstly, the current development of confocal system home and abroad is briefly introduced, then the astigmatism based on the principle of optical detection is analyzed to find out the parameters of astigmatic mirrors and object lens that will affect the resolution of the system. Secondly, the ZEMAX simulation analysis is conducted for the conventional parallel confocal optical detection system; the use of telecentric optical path should be given priority in parallel optical confocal detection system; the telecentric light path is verified to be able to avoid the object space and the problem of horizontal drift in the detection of spatial light field, and to some extent it can guarantee the ability of parallel detection and simplify the central focus information extraction algorithm. This conclusion provides the theoretical ground for the effective set-up of parallel confocal 3-D micro-structure detection system. Thirdly, two kinds of optical paths based astigmatism are analyzed: astigmatic lens is put on the detection and is repalced by the lens near the surface of the detection in the detecting light way, by comparing with the two kinds of MTF curve and specks, found the latter can obtain the high-resolution detection curve; deduced the point spread function in the confocal system based on the principle of astigmatic, and the explorative study in the construction of the system of parallel cofocal based on astigmatism is made. Finally, under the VC + +6.0 development platform, a set of CCD software and image pre-processing procedures are written for the image acquisition and the image pre-processing of the present research.The research is based on the project sponsored by the National Natural Science Foundation of China (NSFC):"The Basic Research into the Micro-Structural Three-Dimensional Image Measurement Technique Based on Parallel Confocal Detection(50775063)". The thesis emphasizes on the theoretical construction of the optical system of parallel confocal detection system based on astigmatism. The research has scientific significance.