Two-wavelength single-shot interferometry

A new surface profiling technique is proposed, which enables us to measure a surface profile without a rounding effect and with extended phase measurement range. It is accomplished by a newly developed two-wavelength imaging system and the local model fitting (LMF) algorithm for carrier pattern analysis. The experimental results demonstrated that the proposed method can measure steep steps fast and accurately with an extended measurement range, while the robustness against vibration of the conventional single-shot methods is maintained.