LIGHT-SCATTERING FROM PERIODIC ROUGH CYLINDRICAL SURFACES

Light scattering from rough cylindrical surfaces at near-zero grazing angle is investigated by applying Beckmann's scalar scattering model t o the surface's tangential planes and superimposing the individual int ensities to form the scattering pattern. A solution for sinusoidal sur face-roughness profiles is derived and numerical results are obtained to study the influences of surface wavelength and amplitude on the far -field scattering pattern. The spatial and intensity distributions of the fringe (across and along the fringe) are found to be related to th e surface wavelength and amplitude, respectively. Scattering intensity -distribution measurements are carried out on turned surfaces, and the results obtained are in agreement with the model's prediction. As a d irect application, a technique to estimate the surface roughness of tu rned surfaces is proposed. This technique offers an absolute measureme nt in which the roughness amplitude and wavelength of the surface are defined relative to the illumination wavelength.