Determination of the zero-order fringe position in digital speckle pattern interferometry

Area of Science:

• Metrology
• Optical Measurement
• Experimental Physics

Background:

• Digital Speckle Pattern Interferometry (DSPI) is a powerful technique for measuring surface deformation.
• Accurate determination of the zero-order fringe is crucial for quantitative analysis in interferometric experiments.
• Existing phase-shifting methods can be sensitive to experimental noise and require multiple phase-shifted fringe patterns.

Purpose of the Study:

• To propose a novel method for identifying the zero-order fringe position in DSPI.
• To offer a complementary technique to established phase-shifting interferometry.
• To validate the proposed method through experimental demonstration.

Main Methods:

• A novel averaging procedure is employed using images acquired before and after the application of a load.
• The method involves analyzing shifted fringe patterns to pinpoint the zero-order fringe.
• This approach is designed to be robust and straightforward to implement.

Main Results:

• The proposed method successfully determines the position of the zero-order fringe in metrological experiments.
• Experimental results demonstrate the effectiveness and reliability of the technique.
• The method provides a valuable alternative or supplement to phase-shifting techniques.

Conclusions:

• A new, effective method for zero-order fringe localization in DSPI has been developed.
• The technique offers a practical solution for enhancing quantitative analysis in interferometry.
• This advancement contributes to more accurate and accessible metrological measurements.