This paper introduces a method for the determination of the slope and period of oblique and equi-spaced fringes by pattern correlation. In the method, two pairs of image patches in two different regions of a fringe pattern are selected for pattern correlation calculations, and the phase shift between the two selected regions of the fringe pattern is obtained from the phase curves computed with the correlation function. The computer simulation and experiment have shown that this method is useful in interferometry and laser interference lithography for determining the slope and period of the oblique and equi-spaced fringe patterns with the advantage of high resistance to noise. It has potential applications for the measurement of the fringe pattern period, fringe angle, phase difference, displacement, and other relevant physical quantities. In practice, it can also be used for the orientation of interference patterns and alignment of laser interference lithography systems.
Lanjiao Liu Dayou Li Zuobin Wang Haiyan Pan Jia Xu Hongmei Xu Zhengxun Song Zhankun Weng Zhen Hu Jin Zhang Yong Yue
CNM & IJRCNB Centers Changchun University of Science and TechnologyChangchun,China Institute for Research in Applicable ComputingUniversity of BedfordshireLuton,UK CNM & IJRCNB Centers Changchun University of Science and Technology Changchun,China School of Engine CNM & IJRCNB CentersChangchun University of Science and TechnologyChangchun,China Institute of Optics and Electronics Chinese Academy of Sciences Chengdu,China