Multispectral backscattering Mueller matrix imaging on thick fresh tissues

Abstract

It has been demonstrated in many biomedical applications that polarization imaging is capable of label-free probing quantitatively the characteristic microstructural features of complex biological specimens. In a recent study, we carried on backscattering Muller matrix imaging on bovine skeletal muscle sample, and we demonstrated that the information of Mueller matrix is valuable for physiological status characterizing, and may be useful for monitoring meat qualities in food industry. In this work, we report an upgraded system with LED light sources of six different colors ranging from the blue to the near IR-I region. The system is calibrated for taking multispectral Mueller matrix images using a single set of rotating achromatic quarter-wave plates. In this in situ application on imaging of thick fresh tissue samples, we demonstrated that the multispectral polarized light backscattering measurements help to reveal more details on the microstructure of the sample, particularly help to separate different effects due to photon scattering and propagation. The experimental results are compared against Monte Carlo (MC) simulations based on sphere-cylinder birefringence models which approximate the complex tissues to a mixture of spherical and cylindrical scatterers embedded in interstitial media. The simulated results provide more evidence for understanding the contrast mechanism of the polarization features.