Adaptive and automatic diffraction order filtering by singular value decomposition in off-axis digital holographic...

Area of Science:

• Optics and Photonics
• Digital Imaging
• Metrology

Background:

• Digital holography provides quantitative phase contrast maps crucial for imaging, display, and metrology.
• Standard processing involves multiple numerical steps like twin-image suppression and aberration compensation.

Purpose of the Study:

• To propose a new method for suppressing zero-order and twin images in off-axis digital holography.
• To address challenges in portable holographic microscopy where reference beam properties are unknown.

Main Methods:

• Development of a singular value decomposition (SVD) filtering technique.
• Application of SVD filtering for automatic selection of the desired real diffraction order.
• Validation against traditional Fourier spatial filtering methods.

Main Results:

• The proposed SVD filtering effectively suppresses zero-order and twin images in off-axis configurations.
• The method performs well even without prior knowledge of the reference beam's frequency and curvature.
• Successful validation across diverse experimental conditions and with biological samples.

Conclusions:

• Singular value decomposition filtering offers a robust solution for image reconstruction in off-axis digital holography.
• This method is particularly beneficial for portable holographic microscope systems in lab-on-a-chip applications.
• The SVD approach provides a reliable alternative to conventional Fourier filtering for phase contrast enhancement.