2π ambiguity-free digital holography method for stepped phase imaging.

Area of Science:

• Optics and Photonics
• Digital Imaging
• Metrology

Background:

• Phase ambiguity is a persistent challenge in digital holography, limiting measurement accuracy.
• The 2π phase wrapping problem hinders the precise reconstruction of wavefronts.
• Existing methods often struggle with complex phase distributions.

Purpose of the Study:

• To develop a digital holography method that inherently overcomes phase ambiguity.
• To accurately calculate the true phase without wrapping errors.
• To expand the application scope of digital holography.

Main Methods:

• A quasianalytic approach is employed to construct and solve an equation for phase retrieval.
• The method avoids iterative or phase-unwrapping algorithms.
• Numerical simulations and experimental validation are used.

Main Results:

• The proposed method successfully eliminates the 2π phase ambiguity.
• Accurate retrieval of true phase, even for distributions up to 16π, was demonstrated experimentally.
• Effectiveness and accuracy were confirmed through simulations and real-world data.

Conclusions:

• The quasianalytic digital holography method provides an unambiguous phase reconstruction.
• This technique significantly enhances the reliability and potential applications of digital holography.
• The method offers a robust solution for overcoming phase wrapping issues in optical measurements.