Polarization phase unwrapping by a dual-wavelength Mueller matrix imaging system

Area of Science:

• Optics and Photonics
• Biomedical Imaging
• Materials Science

Background:

• Polarization phase wrapping complicates accurate measurement of optical anisotropy.
• Mueller matrix imaging provides rich polarization information but is susceptible to phase wrapping in certain samples.

Purpose of the Study:

• To develop and validate a dual-wavelength Mueller matrix imaging system for polarization phase unwrapping.
• To improve the accuracy of birefringence and orientation measurements.
• To enable analysis of both static and dynamic samples.

Main Methods:

• Simultaneous acquisition of Mueller matrix images at 633 nm and 870 nm.
• Phase unwrapping algorithms applied to dual-wavelength data.
• Monte Carlo simulations to analyze phase wrapping effects.
• Experimental validation using porous alumina and multilayer tapes.

Main Results:

• Achieved relative error of 3% for linear retardance and 6° for birefringence orientation after phase unwrapping.
• Demonstrated feasibility of phase unwrapping for thick or birefringent samples.
• Verified system performance on diverse materials.

Conclusions:

• The dual-wavelength Mueller matrix imaging system effectively overcomes polarization phase wrapping.
• The system is crucial for accurate anisotropy analysis in static samples.
• It enables the study of temporal polarization changes in dynamic biological tissues.