Estimation of wavelength difference using scale adjustment in two-wavelength digital holographic interferometry

Area of Science:

• Optics and Photonics
• Interferometry
• Digital Holography

Background:

• Two-wavelength digital holographic interferometry is a powerful technique for measurements.
• Accurate estimation of wavelength difference is crucial for precise holographic measurements.
• Existing methods may have limitations in accuracy or complexity.

Purpose of the Study:

• To propose and validate a new method for estimating wavelength difference in two-wavelength digital holographic interferometry.
• To improve the accuracy and practicality of wavelength difference estimation.
• To leverage scale adjustment in the reconstruction plane for this purpose.

Main Methods:

• Reconstruction of two holograms recorded at different wavelengths using the Fresnel diffraction integral.
• Analysis of pixel sizes in the reconstruction plane, which are wavelength-dependent.
• Application of a zero-padding method and an intensity correlation function for pixel size adjustment.
• Calculation of wavelength difference based on the adjusted pixel sizes.

Main Results:

• The proposed method successfully estimates the wavelength difference.
• Theoretical predictions align with experimental outcomes.
• The scale adjustment technique effectively utilizes pixel size variations.

Conclusions:

• The developed method provides a reliable approach for wavelength difference estimation in two-wavelength digital holographic interferometry.
• The technique demonstrates practical utility and accuracy.
• Scale adjustment offers a viable strategy for enhancing holographic measurement precision.