Verification of phase measurement error sources in phase-shifting interferometry with four step phase-shifting...

Area of Science:

• Optical Metrology
• Interferometry
• Image Processing

Background:

• Phase-shifting techniques are crucial in interferometry but susceptible to systematic and random errors.
• Common errors include miscalibration, nonlinear responses, tilt shifts, nonlinear recording, speckles, and fringe fluctuations.
• Accurate error identification is vital for reliable interferometric measurements.

Purpose of the Study:

• To propose a new method for verifying phase measurement error sources in interferometry.
• To introduce a grayscale image representation for more expressive error visualization.
• To enable qualitative estimation of error magnitudes prior to experimental execution.

Main Methods:

• A four-step phase-shifting algorithm is used to generate a lattice-site representation.
• This representation is transformed into a grayscale image depicting phase-shift angle distributions.
• The shape and characteristics of the grayscale image are analyzed to identify error sources.

Main Results:

• The grayscale image provides a more demonstrative visualization of error sources compared to traditional dot distributions.
• The method allows for the recognition of various systematic and random errors affecting phase measurements.
• Qualitative estimation of error magnitudes is achievable before conducting experiments.

Conclusions:

• The proposed grayscale image method offers a valuable tool for diagnosing phase measurement errors in interferometry.
• This technique enhances the reliability of phase-shifting measurements by enabling pre-experimental error assessment.
• The method is applicable to diverse interferometric applications, including Fizeau interferometry and fringe projection profilometry.