Steps length error detector algorithm in phase-shifting interferometry using Radon transform as a profile...

Area of Science:

• Optics and Photonics
• Metrology
• Digital Image Processing

Background:

• Phase-shifting interferometry is crucial for precise displacement estimation.
• Phase shifter miscalibration is a common and significant error source.
• Existing methods struggle with unexpected phase shifts and device variability.

Purpose of the Study:

• To develop a novel technique for detecting and measuring phase shifter calibration errors.
• To address the challenge of unexpected phase shifts in interferometric measurements.
• To provide an alternative method for phase shifter calibration.

Main Methods:

• Utilizes the Radon transform for automatic calibration and profile measurement.
• Analyzes specific zones of interferograms to register maximum and minimum value parameters.
• Applies the method to both synthetic and real interferograms.

Main Results:

• The proposed algorithm effectively detects and quantifies calibration errors in phase-shifting interferometry.
• Achieved good approximations for error measurement across various interferogram fringe distributions and phase-shifting steps.
• Demonstrated the algorithm's ability to measure deviations in phase-shifting steps.

Conclusions:

• The Radon transform-based method offers a robust solution for phase shifter calibration errors.
• This technique provides a reliable alternative for calibrating phase shifter devices.
• The algorithm is effective regardless of interferogram complexity or step variations.