Coherent anti-Stokes Raman Fourier ptychography.

Area of Science:

• Optical Microscopy
• Spectroscopy
• Computational Imaging

Background:

• Coherent anti-Stokes Raman scattering (CARS) microscopy offers label-free chemical imaging.
• Existing CARS wide-field imaging schemes have limitations in resolution and information retrieval.
• Fourier ptychography principles can potentially enhance CARS imaging capabilities.

Purpose of the Study:

• To theoretically and numerically investigate a novel CARS Fourier ptychography microscopy (CARS-FPM) scheme.
• To develop a method for reconstructing Raman scatterer density distribution from CARS images.
• To achieve improved resolution and extract both real and imaginary parts of susceptibility for comprehensive sample analysis.

Main Methods:

• Development of a theoretical framework for CARS-FPM.
• Numerical reconstruction of Raman scatterer density from CARS images acquired at various pump/Stokes beam incidence angles.
• Application of an accurate vectorial model for image inversion.

Main Results:

• Successful theoretical and numerical demonstration of CARS-FPM.
• Reconstruction of Raman scatterer density distribution.
• Extraction of both real and imaginary parts of the sample's susceptibility.
• Achieved improved resolution in CARS imaging.

Conclusions:

• CARS-FPM is a viable and novel approach for advanced CARS microscopy.
• The developed inversion procedure accurately links CARS images to sample properties.
• This technique provides enhanced Raman information and resolution compared to previous methods.