Laser speckle computation for the evaluation of surface roughness

Surface roughness evaluation of optically rough metal plate (Al-6061) by laser speckle imaging method is reported. When the crust portion of metal is illuminated by the monochromatic laser beam, the reflected light from the surface produce granular speckle pattern due to the composite effect of scattering and interference. The captured pattern is used for roughness assessment by soft computing technique. The results are fair in consent while compared with the conventional stylus profiler.