Multi-filter transport of intensity equation solver with equalized noise sensitivity

Area of Science:

• Optics
• Image Processing
• Computational Physics

Background:

• Phase retrieval is crucial for characterizing complex fields.
• Transport of Intensity Equation (TIE) methods are established for phase recovery.
• Unequally spaced measurement planes can enhance TIE performance.

Purpose of the Study:

• To develop an accurate phase retrieval algorithm using TIE with unequally spaced planes.
• To improve phase recovery accuracy and minimize phase error.
• To introduce a novel plane selection strategy for noise robustness.

Main Methods:

• Utilizing intensity measurements at unequal plane separations.
• Employing multiple band-pass filters in the frequency domain of the axial derivative.
• Deriving a new plane selection strategy to equalize error contributions from frequency bands.

Main Results:

• Accurate phase recovery of complex objects from intensity measurements.
• Highest accuracy for TIE-based phase recovery with minimal phase error.
• Demonstrated control over retrieved phase error without a priori object information.
• Numerical simulations confirm stability and robustness.

Conclusions:

• The presented algorithm offers superior accuracy and robustness for TIE-based phase retrieval.
• The novel plane selection strategy allows for error control and reduces reliance on prior knowledge.
• This technique advances phase retrieval capabilities for complex optical fields.