Axial standing-wave illumination frequency-domain imaging (SWIF)

Area of Science:

• Biomedical imaging
• Optical microscopy
• Fluorescence imaging

Background:

• Conventional microscopy techniques (wide-field, scanning, light-sheet) have trade-offs between resolution, field-of-view, phototoxicity, and speed.
• These limitations are often due to spatial sampling with diffracting beams.

Purpose of the Study:

• To introduce a novel fluorescence imaging strategy, SWIF (Spatial Wavefront Imaging).
• To overcome the inherent trade-offs in conventional microscopy by encoding axial sample information in the Fourier domain.

Main Methods:

• Utilized propagation-invariant illumination patterns capable of extending over millimeters.
• Demonstrated robust propagation through layers with varying refractive indices.
• Encoded the axial profile of a sample in the Fourier domain.

Main Results:

• Achieved imaging of a lateral field-of-view of 0.8 mm x 1.5 mm.
• Obtained an axial resolution of 2.4 µm.
• Exceeded the lateral field-of-view of conventional techniques (~100 µm) at comparable resolution.

Conclusions:

• SWIF surpasses the limitations imposed by diffracting illumination beams.
• This technique effectively decouples lateral field-of-view from resolution in fluorescence imaging.
• SWIF offers a significant advancement for biomedical research and diagnostics.