Theoretical And Experimental Study Of Digital Holographic Microscopic Measuring

Digital holography is a new imaging technique, which is developed on the base of optical holography, Digital processing and Computer techniques. It is using Charge Coupled Device(CCD) instead of the conventional silver to record hologram, Then reproduce the 3D contour object measurement by the way of computer simulationin. Compared with the traditional optical holographic, the whole process simple measuring, lower production cost, faster the imaging speed, and with the advantages of non-contact real-time measurement. At present, it can be used in the feilds of the morphology detection of tiny objects, micro deformation analysis, and biological cells shape measurement. It is one of the research hot spot at home and abroad.This thesis mainly study digital holographic that use for three dimensional profile measurement of tiny objects combine the theoretical analysis and the experiments investigate, and the main research works as follows:This paper introduce the basic principle and relevant theory about the optical holography and Digital holography, and research the basic questions which influence the reproduce images in the precess of recording and reconstructioning of the digital holographic microcopy. In order to get a clear digital hologram, by analysising the optical systerm struction, we discuss the recording distance and the angle between the object light and the reference light on the hologram.On the basic of the theoretical studies, we establish a measurement and analysis the expermental conditions, then adjust the systerm. To achieve a precise measurement of tiny objects in three-dimensional, we measure several tiny objects such as MEMS micro devices, aspheric combination device, micro lens array measurement, and respectively obtain their reproduction three-dimensional contour, realize the tiny objects of three dimensional profile measurement. According to the experiment results consider:analysising the reference factors between the zero-order term and a pair of twin-images by the choice of the angle of the object light and the reference light and the distance of the recording and reconstructing and the characteristics of reconstruction light on the measurement, the measurement errors were analyzed. The reasearch result shows that the device has the certain reliablity.