Correction of Scanning Steps to Improve Accuracy in Interferometric Profilometer

Abstract

In scanning interferometry of longitudinal shift, an uncertainty of required phase shift performance leads to a measurement error. Such uncertainty can be caused by external factors (vibrations, air turbulence in measuring area etc.) as well as inaccuracy of the scanning system. The method for calculating the phase shift between interferograms, which allows reducing the measurement error, is proposed. The results of numerical and full scale experiments are presented.

Keywords

• Phase shifting interferometry
• nanorelief measurement
• measurement error