The Simulational Studies On The Characterizations Of Sinc Correlation Random Surfaces And Light Scattering And The Measurement Of Random Surfaces

Random surfaces often can be found from small objects as paper slip to large objects as mountains in the nature,and it also necessarily makes up of modern precision instruments. So many people have payed attention to studying about random surfaces for a long time.At present,contact and non-contact methods are used to study random surfaces. Contact methods commonly are used to measure random surfaces with precision instruments,while non-contact methods are used to measure random surfaces in optics ways. Light scattering ways are abroadly adopted to study random surfaces as one of non-contact methods. Correlative experiment and theory investigation have proved that intensity speckle has distinctly relative with self-correlation function of random surfaces.So the parameters of random surfaces can be measured from light scattering profiles.The bright ring of light scattering profiles have been found recently from exprimental measure in the literature. However, this phenomenon can not be explained by using ordinary surface models,so someone have supposed that this phenomenon was brought by the oscillation of self-correlation function of random surface. This paper have proposed a new surface model which is expressed by mathematical Sinc function. We have defined this surface model as Sinc correlation random surface which have distinctly oscillating property in self-correlation function of random surface. And the methods of simulating surface samples and light scattering profiles are proposed in this paper.In addition,the theoretical analysis of light scattering profiles are obtained in limited condition of scattering genes. So we can conclude that the oscillation of self-correlation of random surface can not bring the appearance of light ring. Finally,the methods of measuring the parameters of Sinc random surfaces are gained from the light scattering profiles. The whole paper is divided into five chapters. Chapter 1 gives a summary and review of the description of random surfaces and its measurements, the fundamental theories of light scattering and the methods of measuring surface parameters .In chapter 2, the self-affine fractal random surface and light scattering properties are mostly introduced, which gives the simulation of suface samples and light scattering profiles.In chapter 3, sinc correlation surface model have been proposed for the first time. The samples of random surfaces and light scattering profiles are derived from self-correlation function of surface. And we also derive the theoretical approximate funtion of scattering profiles when the scattering geneΩtakes either very small or very large values. We have found that theoretical analysis is consistent with simulated outcome of light scattering profiles. Because there is different properties in the shape of scattering profiles and self-correlation of random surfaces, we can conclude that the oscillation of self-correlation function can not bring the light ring of intensity profiles.Chapter 4 gives the methods of measuring the root-mean-square deviation roughness w and lateral correlation lengthξof Sinc correlation random surfaces in the light scattering profiles.In chapter 5,we give the summary of this paper.