Phase-derivative-based estimation of a digital reference wave from a single off-axis digital hologram

Area of Science:

• Optics and Photonics
• Digital Holography
• Image Processing

Background:

• Accurate digital reference wave estimation is crucial for high-fidelity holographic reconstruction.
• Existing methods often rely on reference flat plates or are susceptible to speckle noise.
• Phase unwrapping can introduce artifacts and errors in the reconstructed wavefront.

Purpose of the Study:

• To develop a method for estimating the digital reference wave from a single off-axis digital hologram.
• To achieve a digital reference wave that closely matches the experimental reference wave.
• To overcome limitations of existing methods, such as dependence on reference flat plates and speckle noise.

Main Methods:

• Estimation of digital reference wave parameters directly from recorded phase information.
• Utilizing phase derivatives to extract off-axis tilt angle and curvature without phase unwrapping.
• Independent of reference flat plates and speckles.

Main Results:

• Successful estimation of digital reference wave parameters from single off-axis digital holograms.
• Demonstration of the method's independence from reference flat plates and speckles.
• Experimental validation of the proposed technique.

Conclusions:

• The proposed method provides an accurate estimation of the digital reference wave.
• It effectively avoids phase unwrapping issues and associated problems.
• This technique enhances the fidelity of reconstructed images in digital holography.