RT - Journal Article T1 - Formulation of Linear L-Fork Gratings' Moiré Pattern using Reciprocal Vector and investigation of its applications JF - opsi YR - 2014 JO - opsi VO - 20 IS - 0 UR - http://opsi.ir/article-1-58-en.html SP - 49 EP - 52 K1 - moiré K1 - l-fork grating K1 - displacement measurement AB - Use of Fourier frequency domain is one of the usual methods for studying moiré pattern. In this method, spatial frequency spectrum of the moiré pattern instead of its intensity profile is used. Comparing with other methods, this method is very simple. In this work, we present a formulation for the moiré pattern of superimposing two linear l-fork gratings using reciprocal vector approach. For this kind of moiré pattern some applications are presented such as 2D displacement measurement. In addition, effect of changing relative angle of the grating lines is investigated and we find that it is possible to extract the topological defects of the gratings by the moiré technique. Finally, we introduced a simple way for variable frequency l-fork shape patterns generation by superimposing of two rotating l-fork gratings. LA eng UL http://opsi.ir/article-1-58-en.html M3 ER -