Review for Stokes-vector and Mueller-matrix polarization imaging technology: principles, implementation and applications.

This review systematically summarizes the principles, technological advancements, and diverse applications of Stokes-vector and Mueller-matrix polarization imaging (PI). The polarization of light is a fundamental property that provides unique and valuable information about the interaction between light and matter. While traditional polarimetry is limited to point-by-point measurements, PI captures the polarization state in a two-dimensional scene, generating a spatial map of parameters for complex and heterogeneous systems. The Stokes-Mueller formalism is the only complete mathematical tool for polarization analysis, using the Stokes vector to describe the light's state and the Mueller matrix as the transfer function to fully characterize the polarization-altering properties of any medium, including complex depolarizing tissues. The evolution of PI from time-sequential to snapshot paradigms represents a pivotal shift, driven by the pressing need for real-time, motion-artifact-free characterization of dynamic systems. While time-sequential systems laid the foundational framework, their inherent trade-off between acquisition speed and polarization completeness has spurred intense innovation in snapshot methodologies. This transition is not merely a technical improvement but a fundamental enabler for applying polarization analysis toin vivobiological processes and real-time industrial inspection. Applications of PI are wide-ranging, including label-free diagnostics for cancer detection, non-destructive analysis of anisotropic materials, polarization-enhanced target detection, and so on. A future direction is the convergence of PI with hyperspectral detection to form 'hyper-Stokes/Mueller imaging,' which promises unprecedented specificity and real-time capability.