Phase-stepping automatic fringe analysis in holographic moiré

Area of Science:

• Optical metrology
• Interferometry
• Holography

Background:

• Holographic moiré patterns are crucial for precise measurements.
• Analyzing phase functions in these patterns traditionally requires complex methods.
• Existing techniques can be cumbersome and necessitate additional optical components.

Purpose of the Study:

• To introduce novel phase-stepping techniques for holographic moiré analysis.
• To enable instantaneous determination of phase functions.
• To simplify holographic moiré interferometry arrangements.

Main Methods:

• Application of phase-stepping technique to holographic moiré patterns.
• Development of two modified self-calibrating phase-stepping methods.
• Demonstration using computer-generated noisy moiré patterns.

Main Results:

• Instantaneous determination of phase functions in both moiré and carrier fringes achieved.
• Proposed techniques demonstrated successfully on noisy data.
• No added complexity to the holographic moiré setup was required.

Conclusions:

• The novel phase-stepping techniques offer an efficient and simplified approach to holographic moiré analysis.
• These methods eliminate the need for auxiliary carrier fringes.
• The adapted holographic moiré interferometer is suitable for these advanced phase-stepping techniques.