Phase Objects Interferometry With Scanning And Imaging Technology

The study of measurement imaging and of phase objects is an importanttopic of holographic optical technologies. The imaging technologies ofphase objects are playing an important role in biology, medicine andindustrial production. Traditional imaging technologies of phase object,especially imaging of biological samples and weak absorption transparentobjects, have a very long history of development. With the developmentof microscopic measurement technologies, some of the more maturetechnologies are already industrialized. However, traditional imagingtechnologies not only require that the phase of the sample is less than1, but also cannot measure the phase quantitatively. So the applicationsof these technologies are greatly restricted.Respecting the shortages mentioned above, a new technology formeasurement and imaging of the phase object is propounded——interferencemeasurement and scanning imaging technology for phase object. It canrealize not only the quantitative measurement of phase but also theimaging of phase object. There are many forms to display the image, suchas pseudo color images, gray-level images and three-dimensional images.On the basis of Young's interference theory, the experimentalmeasurement and imaging system of phase object is preliminarily built.The phase measurement and imaging algorithm is designed, and themeasurement and imaging of some samples are analyzed. The meaningfulresults are gained. The main work finished and the research productionacquired are as follows:First, the development of phase objects imaging technologies andtheir theories are summarized, with a representative of the Dark FieldMethod, Schlieren Method and Phase Contrast Method for the main subject.The advantages and disadvantages of the methods are discussed. Second, the interference measurement and scanning imaging technologyfor phase object is propounded. The interference measurement and scanningimaging technology is analyzed theoretically, and the phase resolutionand linear measurement range is discussed. The analyses show that he phaseresolution can reachπ/15～π/15 and the measurement range can reach 2π,which is the superiority of this technology.Third, the experimental measurement system is designed and builtpreliminarily. The transverse imaging resolution and imaging region isdiscussed. Two important parts of the system are analyzed, which arescanning platform and fringes image acquisition system.Fourth, the periodic fringes binary image algorithm is proposed tomeasure the interference fringes. Image processing software is designedto measure the period and the displacement of the fringes. The concreteprocess of computing the phase is analyzed. The impact caused by thefringes gradient and contrast is discussed. The components and functionof the software is introduced.Fifth, measurement and imaging experiments are done for some phaseobject such as ITO film, and the results are analyzed and compared.