Dynamic Phase Measurement Based on Two-Step Spatial Carrier-Frequency Phase-Shifting Interferometry

A dynamic phase measurement method based on a two-step spatial carrier-frequency phase-shifting (TS-SCFPS) technique is proposed. First, by the subtraction operation between a pair spatial carrier-frequency interferograms with a certain phase shifts, which are captured by dual-channel interferometry system, we can achieve one-frame background-removed carrier-frequency interferogram. Second, from two-frame phase-shifting subinterferograms splitting from the above background-removed carrier-frequency interferogram, we can rapidly achieve the accurate phase through using a two-step orthogonal and normalization algorithm. Compared with the existing SCFPS methods, the proposed TS-SCFPS method reveals good background deductions and antinoise performance. Moreover, by using a two-step phase-shifting algorithm, without any special requirement for the phase shifts, the proposed TS-SCFPS method can rapidly achieve high-accuracy phase retrieval relative to other SCFPS methods. Especially, the achieved experimental results demonstrate the outstanding performance of the proposed TS-SCFPS method in both static and dynamic phase measurements.