Simplified paraboloid phase model-based phase tracker for demodulation of a single complex fringe

Area of Science:

• Optical Metrology
• Image Processing

Background:

• Regularized phase tracker (RPT) is effective for single closed-fringe pattern demodulation.
• Existing RPT methods face challenges with lengthy computation, specific scanning strategies, and sign ambiguity, especially for complex patterns.

Purpose of the Study:

• To propose a simplified paraboloid phase model-based regularized phase tracker (SPRPT) for efficient and robust fringe pattern demodulation.
• To overcome limitations of existing RPT methods, including computation time and robustness against noise and sign ambiguity.

Main Methods:

• Pre-determining first and second phase derivatives using the density-direction-combined method and discrete higher-order demodulation algorithm.
• Simplifying the cost function for significant reduction in computation time.
• Utilizing a paraboloid phase model for enhanced accuracy and noise robustness.

Main Results:

• The SPRPT method achieved higher accuracy with less computational time compared to existing RPT methods in simulations.
• Experimental validation using electronic speckle pattern interferometry demonstrated the method's robustness against noise and its accuracy.
• The proposed method eliminates the need for specifically designed scanning strategies and is robust against sign ambiguity.

Conclusions:

• The SPRPT method offers a significant improvement in efficiency and robustness for demodulating complex and noisy fringe patterns.
• The method is feasible for both static and dynamic applications in optical metrology.
• SPRPT provides a more accurate and computationally efficient alternative to traditional RPT techniques.