MONITORING THE OPTICAL POLISHING PROCESS BY SPECKLE STATISTICS

The grade of optical finish of a surface being polished can be measure d by its scattering properties. In coherent illumination a partially d eveloped speckle field is obtained, whose standard deviation is relate d to the finish grade. Measurements are reported on a series of sample surfaces produced with a traceable procedure. The polishing rate is g iven with a simple model, and fitting to the data set is presented. Wi thin the sensitivity of the measuring technique, a fair agreement betw een the model and the data is achieved.