RT - Journal Article T1 - Analyzing moirĂ© pattern for calculating nonlinear refractive index in an Azo dye JF - opsi YR - 2018 JO - opsi VO - 24 IS - 0 UR - http://opsi.ir/article-1-1579-en.html SP - 393 EP - 396 K1 - MoirĂ© deflectometer K1 - diffraction gratings K1 - Disperse Orange 25 K1 - nonlinear refractive index AB - In this paper, the change of moiré pattern by a nonlinear sample (Disperse Orange 25) has been studied. By analyzing the intensity distribution graph of moiré pattern, in MATLAB software, a microscopic rotation of 0.0017radian was measured respect to linear regime. Furthermore we have calculated the nonlinear refractive index of order for 1mM concentration of sample by this method. LA eng UL http://opsi.ir/article-1-1579-en.html M3 ER -