Packed domain Rayleigh-Sommerfeld wavefield propagation for large targets

Area of Science:

• Optics
• Digital Holography
• Wave Propagation

Background:

• Digital holographic microscopy (DHM) requires efficient wave propagation algorithms.
• Current methods can be computationally intensive, limiting real-time applications.

Purpose of the Study:

• To present a novel, fast algorithm for propagating scalar wave fields in DHM.
• To enable propagation from a small source to an extended target area with coarser sampling.

Main Methods:

• Utilizing the first Rayleigh-Sommerfeld diffraction formula.
• Decomposing the convolution kernel into patches for fast Fourier transform (FFT) application.
• Employing partial overlapping and soft blending for spectrum reduction.
• Storing significant spectral components in a sparse array structure.

Main Results:

• The algorithm achieves rapid evaluation of wave propagation by skipping negligible Fourier components.
• Demonstrated efficient mapping of results to a coarsely sampled target area.
• Experimental verification at a numerical aperture of 0.62 showed no significant resolution limitations.

Conclusions:

• The developed algorithm offers a significant speed improvement for wave field propagation in DHM.
• It maintains high resolution, making it suitable for demanding imaging applications.
• This method enhances the practicality and efficiency of digital holographic microscopy.