Rasouli Saifollah, Ghasemi H, Tavassoly M T, Khalesifard H R
Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, Iran.
Appl Opt. 2011 Jun 1;50(16):2356-60. doi: 10.1364/AO.50.002356.
In this paper, the application of "parallel" moiré deflectometry in measuring the nonlinear refractive index of materials is reported. In "parallel" moiré deflectometry the grating vectors are parallel, and the resulting moiré fringes are also parallel to the grating lines. Compared to "rotational" moiré deflectometry and the Z-scan technique, which cannot easily determine the moiré fringe's angle of rotation and is sensitive to power fluctuations, respectively, "parallel" moiré deflectometry is more reliable, which allows one to measure the radius of curvature of the light beam by measuring the moiré fringe spacing. The nonlinear refractive index of the sample, including the sense of the change, is obtained from the moiré fringe spacing curve. The method is applied for measuring the nonlinear refractive index of ferrofluids.
本文报道了“平行”莫尔偏折术在测量材料非线性折射率中的应用。在“平行”莫尔偏折术中，光栅矢量是平行的，所产生的莫尔条纹也与光栅线平行。与“旋转”莫尔偏折术和Z扫描技术相比，“旋转”莫尔偏折术不易确定莫尔条纹的旋转角度，Z扫描技术对功率波动敏感，而“平行”莫尔偏折术更可靠，它允许通过测量莫尔条纹间距来测量光束的曲率半径。从莫尔条纹间距曲线可得到样品的非线性折射率，包括变化的方向。该方法用于测量铁磁流体的非线性折射率。
