Effect of piezoelectric transducer nonlinearity on phase shift interferometry

Area of Science:

• Optical Metrology
• Materials Science

Background:

• Piezoelectric transducers (PZT) are crucial for precise motion control in interferometry.
• Nonlinearity in PZT motion can introduce errors in phase measurement.
• Phase shift interferometry relies on accurate phase data for quantitative analysis.

Purpose of the Study:

• To analyze the impact of quadratic nonlinearity in PZT motion on phase shift interferometry.
• To establish a relationship between PZT nonlinearity and phase error.
• To compare the performance of different algorithms under PZT nonlinearity.

Main Methods:

• Utilizing the Fresnel integral to calculate integrated intensity for quadratic PZT nonlinearity.
• Analyzing the root-mean-square (rms) phase error in relation to the quadratic coefficient.
• Comparing the effects of PZT nonlinearity on three- and four-bucket algorithms.

Main Results:

• Integrated intensity can be calculated using Fresnel integral when PZT nonlinearity is quadratic.
• For PZT with minor nonlinearity, rms phase error shows near-linear proportionality to the quadratic coefficient.
• Distinct effects of PZT nonlinearity were observed on the three- and four-bucket algorithms.

Conclusions:

• The study provides a method to quantify phase errors due to PZT nonlinearity.
• Understanding this relationship is vital for improving the accuracy of phase shift interferometry.
• Algorithm choice impacts robustness against PZT motion nonlinearity.