Experimental investigations and parametric studies of surface roughness measurements using spectrally correlated speckle images

Abstract

The surface roughness parameters encoded in a speckle pattern can be effectively extracted through correlation experiments. In the case of spectrally correlated speckle images, the degree of decorrelation arises from wavelength difference in the laser light irradiated on the surface. To obtain accurate results in such methodology, a proper design of experiments is important due to more than one parameter involved in the experiment. Here, experimental investigations and parametric studies of surface roughness measurements using spectral speckle correlation methodology are presented, considering the potential variables in the system. The sources of error and factors affecting the accuracy in measurement are identified and the experimental results obtained from standard calibration plate samples are presented.