Complex spatial illumination optimization method for backscattering Mueller matrix polarized light tissue imaging

In recent years, polarization imaging technology has demonstrated great potential in biomedical research and clinical applications. As a novel biomedical optical imaging technique, Mueller matrix full polarimetry technology can obtain rich polarization characteristics of tissue samples, thereby further reflecting their microscopic structure information. However, when obtaining in vivo Mueller matrix images of bulk tissues by using backscattering setup, the inhomogeneity on the surface of biomedical samples will lead to inaccurate characterization of polarization properties. In this study, we experimentally measure the backscattering Mueller matrix of tissue samples and systematically analyze the polarization aberration characteristics caused by complex spatial illumination conditions. Further, we obtain the aberrations of different spatial illumination schemes in Mueller matrix imaging and provide suggestions for more suitable polarization illumination schemes when extracting specific polarization information. Meanwhile, we also proposed strategies to mitigate polarization aberrations by adjusting the incident and detection angles. The conclusions obtained in this study not only contribute to enhance the accuracy and reliability of Mueller matrix full polarization imaging, but also lay a solid foundation for its further application in quantitative tissue polarization imaging.