Improved phase sensitivity in spectral domain phase microscopy using line-field illumination and self...

Area of Science:

• Biophotonics
• Optical Microscopy
• Cell Biology

Background:

• Quantitative phase microscopy (QPM) is crucial for label-free cell imaging.
• Existing QPM techniques face challenges with phase noise and resolution.
• High numerical aperture (NA) objectives are needed for detailed cellular analysis.

Purpose of the Study:

• To develop a novel quantitative phase microscope (QPM) with enhanced phase stability and high resolution.
• To enable nanometer-scale measurements of cell surface dynamics.
• To demonstrate the capability for 2D surface profiling of cells.

Main Methods:

• Utilizing spectral domain optical coherence tomography (SD-OCT) with line-field illumination.
• Implementing a self-phase-referencing method to mitigate common-mode phase noise.
• Integrating a separate reference arm to allow the use of high numerical aperture (NA > 1) objectives.

Main Results:

• Achieved path-length sensitivity as good as 41 pm/√Hz.
• Successfully detected natural motions of cell surfaces.
• Performed two-dimensional surface profiling of HeLa cells with high resolution.

Conclusions:

• The developed QPM system offers superior phase stability and high resolution for cell motility studies.
• The instrument is suitable for nanometer-scale investigations of cellular dynamics.
• This technology advances label-free imaging capabilities in cell biology.