Two-frame random phase-shifting interferometry immune to the influence of tilted phase-shift

Area of Science:

• Optics and Photonics
• Metrology
• Interferometry

Background:

• Interferometry is crucial for precise measurements but can be affected by tilt phase-shift.
• Existing algorithms may lack robustness or require iterative processes, limiting their practical application.

Purpose of the Study:

• To develop a novel, highly accurate, and robust interferometry algorithm.
• To introduce a method immune to tilt phase-shift for expanded reliability.

Main Methods:

• A random two-frame algorithm leveraging inter-frame phase-shift and intra-frame phase difference equivalence.
• Utilizing light intensity pixels from different images to identify new phase-shift information.
• Employing least squares fitting for a linear random phase-shift plane and inverse tangent relationship for phase distribution calculation.
• Avoiding iterative processes by using light intensity equivalence for phase-shift plane fitting.

Main Results:

• The algorithm demonstrates high accuracy and robustness in phase distribution retrieval.
• Effective suppression of tilt phase-shift influence is achieved.
• Computational efficiency is maintained without iterative calculations.
• Successful verification through simulations and experimental comparisons under tilted and non-tilted conditions.

Conclusions:

• The proposed random two-frame algorithm significantly enhances the reliability of interferometry.
• This method offers a robust and efficient solution for phase measurement, particularly in the presence of tilt phase-shift.