Theoretical And Experimental Studies Of Light Scattering From The Random Surface Based On The Wave Vector Space

The light scattering of random surface has been subject to attention for a long time. It iswidely applied in many fields, such as remote sensing, radar imaging, sonar detection,industrial non-contact detection and biomedical diagnostics and other fields. Therelationship between the morphology of the random surface and the distribution lightscattering intensity is important for the study of random surface light scattering. The presenttheoretical and numerical models can explain the characteristics of the scattering intensity ofthe vast majority of natural and artificial surface. To simulate the scattering intensitydistribution, surface characteristics need to be known; in the case of known space distributionof the scattering intensity, the surface characteristic parameters can be extracted. However, inthe formulation between the surface parameters and the distribution of scattering intensity,regardless of theory and experiment, most of the researchers to calculate the relationshipbetween the scattering angle and the spatial distribution of light intensity in the realspace. This expression form looks complicated; it can not indirectly determine the relationshipbetween the surface and the intensity distribution. Thus, according to the wave-particleduality of photons, the light wave with wave vector to represent the random surface of thelight scattering properties of the wave vector space, the relationship becomes relativelysimple.This paper is based on the correspondence between the spatial distribution of wavevector space of random surfaces and the scattering intensity in the wave vector space and lightscattering of the isotropic and anisotropic surface is been researched. According to thescattering light intensity distribution in the real space, the intensity profile curve of lightscattering is extracted in the vector space, and then based on the Kirchhoff approximationtheory and self-affine fractal random surface model, theoretical and experimental study isdone about the statistical parameters for the surface. The main research works are as follows:1. Surface topography for anisotropic rough samples is measured with atomic forcemicroscopy and the specific morphology of the anisotropic random surface samples is analyzedusing the measurement data. The surface of the sample is sorted into several typical the type according to their characteristics. The relationship between different types of surfaces ofdifferent parameters and light scattering pattern is simulated using computer program.2. The light scattering and light shielding effect of a typical anisotropic microstructure ofthe surface is discussed. According to the law of reflection of light, the scattering orientationcurve is deduced using the operation relations of space-vector. The reflection component inthe measurement plane should satisfy the curve equation, and the theory is verified by thelight scattering experiments of the mirror and cylindrical fiber.3. Based on light scattering theory of random surfaces in the wave vector space, anexperimental method that vertical wave vector remains constant is designed andangle-resolved light scattering measurement method can better measure the statisticalparameters of an isotropic random surface. We made the detector driven by two-dimensionalmobile platform controlled by computer move along a circular arc paralleling to the sampleplane. This arc of a circle normal to the sample surface and observe the intersection of thesurface to reflect light and observe the intersection of the surface as a starting point. In this arc,the vertical wave vector of the scattered light remains unchanged, eliminating the previouslight scattering measurements the vertical wave vector approximation the same error.4. A convenient experimental method measuring light scattering pattern of rough surfaceis designed. Using the receiver screen to receive the scattering pattern, the lens to image thescattering pattern on the receiver screen, the scattering pattern is collected with the CCD. Thescattering pattern is transformed into the light intensity of the wave vector space, and the lightscattering profile is extracted. The scattering profiles of isotropic and anisotropic roughsilicon surface are obtained with this experimental system. For the anisotropic surfacesamples, the scattering profiles are extracted along the orientation curve on the screen. Resultsare compared with measurement of AFM and methods of angle-resolved scattering.The theory and experiment method of light scattering on random surface based on variedwave vector in wave vector space is studied in this paper. It is very important for thedevelopment of the light scattering on random surface to study the light scattering onanisotropic random surface.