Full-field spatially incoherent illumination interferometry: a spatial resolution almost insensitive to aberrations

Area of Science:

• Optical Imaging
• Biomedical Optics
• Interferometry

Background:

• Full-field optical coherence tomography (OCT) is a powerful imaging technique.
• System aberrations can degrade image quality and resolution in OCT.
• Understanding the impact of illumination on aberration tolerance is crucial for OCT development.

Purpose of the Study:

• To investigate the effect of spatially incoherent illumination on the point spread function (PSF) width and spatial resolution in full-field OCT.
• To compare the aberration tolerance of full-field OCT with incoherent illumination to systems using coherent illumination.
• To demonstrate the unique advantage of incoherent illumination in mitigating aberration-induced resolution loss.

Main Methods:

• Theoretical analysis of optical system performance.
• Numerical simulations of light propagation and image formation.
• Experimental validation using full-field OCT setups with varying illumination conditions.

Main Results:

• Spatially incoherent illumination renders the PSF width and spatial resolution of full-field OCT almost insensitive to optical aberrations.
• Aberrations predominantly cause a decrease in signal level, impacting signal-to-noise ratio but not PSF broadening.
• This resilience to aberrations was confirmed through theoretical, numerical, and experimental comparisons with scanning OCT and wide-field OCT using coherent illumination.

Conclusions:

• Incoherent illumination offers a significant advantage for full-field OCT by preserving spatial resolution in the presence of aberrations.
• This finding provides a new strategy for designing robust OCT systems less susceptible to optical imperfections.
• This study presents the first demonstration of aberration insensitivity in full-field OCT utilizing incoherent illumination.