Polarization state tracing method to map local birefringent properties in samples using polarization sensitive...

Area of Science:

• Biomedical Optics
• Optical Coherence Tomography
• Biophysics

Background:

• Birefringent properties of tissues provide valuable diagnostic information.
• Current polarization-sensitive optical coherence tomography (PSOCT) methods can be complex.
• Accurate depth-resolved birefringence mapping is crucial for understanding tissue structure and disease.

Purpose of the Study:

• To develop a simplified method for depth-resolved birefringence measurement using PSOCT.
• To accurately determine the local optic axis and phase retardation in biological samples.
• To demonstrate the method's compatibility with existing PSOCT systems.

Main Methods:

• Utilizing the trajectory of output polarization states on the Poincaré sphere.
• Fitting a plane to adjacent polarization states to determine apparent optic axis and phase retardation.
• Applying 3D rotation operations based on upper layer birefringence to find the local optic axis.

Main Results:

• A novel method for deriving depth-resolved birefringent information was proposed and validated.
• The method successfully mapped local birefringence in ex vivo mouse thigh tissue.
• The technique requires only one input polarization state, simplifying system setup.

Conclusions:

• The proposed method offers a simplified and effective approach for birefringence imaging in biological tissues.
• This technique enhances the utility of PSOCT for in vivo and ex vivo tissue analysis.
• The findings pave the way for improved diagnostic capabilities using optical coherence tomography.