Widefield quantitative polarized light microscopy using spectrally encoded null polarimetry.

Area of Science:

• Biomedical optics
• Microscopy techniques
• Quantitative imaging

Background:

• Quantitative polarized light microscopy is crucial for label-free imaging in biology and pathology.
• Previous work introduced fast laser-scanning birefringence microscopy using near-infrared wavelength-swept lasers.
• Spectral encoding of polarization offers high sensitivity to optical retardation.

Purpose of the Study:

• To adapt fast laser-scanning birefringence microscopy for visible widefield imaging.
• To enable straightforward conversion of existing widefield microscopes for quantitative polarized light imaging.
• To enhance sensitivity and quantitative analysis of birefringent specimens in the visible spectrum.

Main Methods:

• Utilizing a white light source instead of a laser.
• Employing a high-order retarder for spectral encoding of polarization.
• Recording channeled spectra in parallel across the image using a hyperspectral camera.

Main Results:

• Successful transposition of near-infrared technique to visible widefield imaging.
• Demonstration of a hyperspectral imaging approach for birefringence analysis.
• Achieved high sensitivity and quantitative determination of optical properties.

Conclusions:

• The proposed method allows easy conversion of widefield microscopes into quantitative polarized light microscopes.
• This technique provides a sensitive, label-free imaging solution for biological and pathological samples.
• It expands the applicability of advanced birefringence microscopy to standard visible light setups.