Abstract
Various transparent components are recently used in numerous optoelectronic devices. As to ensure the product quality, there is an increasing demand for precision profile measurement of these transparent objects. For biological application, quantitative real-time phase measurement of cells with high transmittance is also a popular issue. Therefore, developing a three-dimensional topography measurement system with high speed and high precision for measuring transparent specimens become important. In this study, a phase shifting differential interference contrast (PS-DIC) topography measurement system with quantitative phase restoration method is developed. First, the feasibility of measuring step height specimen through the DIC technique is studied. A modified Fourier phase integration (MFPI) method is proposed to improve the profile reconstruction precision and reduce the effects of noise. Secondly, a PS-DIC measurement system is designed and developed. The error compensation methods and calibration process are also presented. Then a speed up two step phase shifting algorithm is proposed to accelerate the measuring speed of the system for industrial real-time measurement purpose. Moreover, effects of various specimen geometries on profile measurement precision and optical path difference measurement for biological applications are studied.