Phase retrieval in two-shot phase-shifting interferometry based on phase shift estimation in a local mask.

Area of Science:

• Optical Engineering
• Metrology
• Image Processing

Background:

• Fringe analysis is crucial in phase-shifting interferometry.
• Challenges include limited images, noise, and background modulation.
• Accurate phase retrieval is essential for quantitative analysis.

Purpose of the Study:

• To develop an effective algorithm for phase retrieval from two interferograms.
• To address challenges in two-shot phase-shifting interferometry.
• To enable fast and accurate phase map computation.

Main Methods:

• Phase shift evaluation using local mask, phase fitting, and global optimization.
• Full-field phase map computation via arctangent function.
• Algorithm implemented in MATLAB for accessibility.

Main Results:

• The proposed algorithm efficiently retrieves phase information from two interferograms.
• It demonstrates fast processing times, typically in tens of seconds.
• Computer simulations and experimental results confirm excellent performance.

Conclusions:

• The developed algorithm effectively overcomes limitations in two-shot phase-shifting interferometry.
• It offers a fast and accurate solution for phase retrieval.
• The algorithm provides a valuable tool for optical metrology applications.