Speckle intensity correlation in the diffraction region near rough surfaces and simulational experiments for extraction of surface parametersC. F. Cheng1, 2, M. Liu1, 2, N. Y. Zhang3, S. Y. Teng1, H. S. Song2 and Z. Z. Xu1
1 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences P.O. Box 200-811, Shanghai 201800, PRC
2 Department of Physics, Shandong Normal University Jinan, Shandong, 250014, PRC
3 Shandong Institute of Architecture and Engineering Jinan, Shandong, 250014, PRC
(Received 10 July 2003; accepted in final form 22 January 2004)
Based on the light scattering theory of Kirchoff approximation, the correlation function of the speckle intensities relating to that of the random surfaces is quantitatively formulated in correspondence with the principles of Van Cittert-Zernike theorem. We then propose the method for the extraction of surfaces parameters from the correlation functions of speckles intensity produced by light scattering in the region near the random surfaces. The experiments of light scattering in the region near random self-affine fractal surfaces are simulated, and the 3 parameters, i.e., the roughness w, the lateral correlation length and the roughness exponent , are extracted by fitting the correlation function data of the speckle intensities to the formulated expression. The extracted values of the surface parameters conform well with the set values.
42.25.Fx - Diffraction and scattering.
42.30.Ms - Speckle and moire patterns.
© EDP Sciences 2004