A high accuracy measurement method based on vortex polar axis rotation phase-shifting interferometry (VPAR-PSI)

For higher precision phase shift measurement, based on the characteristics of vortex beam, the manuscript introduces phase shift directly through the polar axis rotation of the vortex beam. Compared to traditional grey-scale modulation, the proposed VPAR-PSI method introduces a phase-shifting directly instead of changing the grey-scale, which not only can largely reduce the deviation caused by traditional PSI phase modulation via grey-scale change, but also can effectively avoid the non-linearity between grey-scale and phase of traditional PSI. For verifying the effectiveness of the method proposed in this manuscript, a simulation experiment, sample experiment, and VPAR-PSI and PSI comparison experiment were conducted. The results show that the proposed VPAR-PSI has a high phase-shifting and demodulation accuracy, and can be well implemented to measurement of optical components. The comparative experimental show that compared to conventional PSI, the measurement results of VPAR-PSI have smaller envelope values (mean envelope reduction of 1.4202λ), smaller RMS and standard deviation (the values decreased by 0.3515, 0.3067, and the percentage decreases were 59.69%, 59.71% respectively), proving that the VPAR-PSI technique are more accurate and stable. © 2020 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Global Science and Technology Forum Pte Ltd.