Partially coherent broadband 3D optical transfer functions with arbitrary temporal and angular power spectra

Area of Science:

• Biophysics
• Optical Imaging
• Microscopy

Background:

• Optical diffraction tomography (ODT) creates 3D images of unlabeled biological samples using refractive index variations.
• Partially coherent illumination is attractive for its simplicity and axial sectioning but struggles with arbitrary light sources.
• Existing methods require source symmetry or discretization, limiting their applicability.

Purpose of the Study:

• To develop a general broadband theory for partially coherent tomographic phase microscopy (TPM).
• To enable quantitative analysis with arbitrary illumination sources, regardless of angular distribution or spectrum.
• To unify the effects of spatial and temporal coherence in a single formulation.

Main Methods:

• Investigated partially coherent TPM using a unified formulation for spatial and temporal coherence.
• Developed a method to compute the optical transfer function for arbitrary broadband sources.
• Analyzed the computational efficiency compared to existing methods.

Main Results:

• Successfully unified spatial and temporal coherence effects for arbitrary sources in ODT.
• Achieved a significant reduction in computational complexity for the optical transfer function calculation (O(n^3) vs. O(mn^4)).
• Demonstrated the potential for quantitative phase microscopy with diverse illumination conditions.

Conclusions:

• The developed theory enables 3D quantitative phase microscopy and refractive index tomography with arbitrary partially coherent sources.
• This approach significantly improves computational efficiency, making advanced imaging accessible.
• Broadens the scope of illumination methods applicable to ODT in various microscopy setups.