Demodulation of a single complex fringe interferogram with a path-independent regularized phase-tracking technique

Area of Science:

• Optical Metrology
• Image Processing

Background:

• The two-dimensional regularized phase-tracking (RPT) is a powerful technique for demodulating interferograms.
• However, RPT struggles with complex interferograms and requires specific scanning strategies.
• Existing methods often fail when dealing with intricate fringe patterns or arbitrary data acquisition.

Purpose of the Study:

• To present an improved phase-tracking algorithm based on RPT.
• To enhance the demodulation of complex interferograms and overcome RPT's limitations.
• To achieve more accurate phase reconstruction in various conditions.

Main Methods:

• Developed an improved algorithm building upon the RPT technique.
• Employed a paraboloid phase model to approximate the phase function.
• Modified the cost functional to identify the smoothest phase solutions within the C(2) function space.

Main Results:

• The modified algorithm maintains RPT's robustness while eliminating sensitivity to stationary points.
• Successfully demodulated complex interferograms acquired using arbitrary scanning schemes.
• Demonstrated superior phase reconstruction accuracy compared to RPT for both noiseless and noisy data.

Conclusions:

• The proposed algorithm offers a robust and accurate solution for interferogram demodulation.
• It effectively handles complex fringe patterns and diverse scanning strategies.
• The enhanced accuracy makes it suitable for demanding metrology applications.