Basic study on the application of parametric spline function to holographic pattern measuring system (HPMS)

The authors have developed a new measuring system (HPMS) for quantitative measurement of microscopic displacement and mechanical vibration with high precision. In this study, to get high accurate smooth curve of fringe pattern from holographic interferograms, the parametric spline function was applied to HPMS, and the relationship between the number of sample data and the error rate was investigated along with some experiment. We reached the result that the error can be neglected if the number of sampled data are more than 10 in the one circle, then the first and last processing method (FLPM) was used to get quantitative pattern of the surface displacement of the vibrating test sample