Interactions between light and matter leave unique imprints on the polarization of radiation. Astronomical polarimetry, the study of polarized light from astrophysical sources, reveals physical processes that spectroscopy and photometry alone cannot. As techniques have advanced, polarimetry has become essential for exploring phenomena such as the role of magnetic fields in star formation and the early universe.

This book offers a unified overview of the theory, instrumentation, and astrophysical applications of polarimetry. It explains how polarization arises, how instrumental effects influence observations, and how these can be addressed through design and data reduction. Aimed at researchers and graduate students, it features real-world polarimeter architectures to illustrate key concepts and practical techniques.

Key features: * Polarimetry is becoming an increasingly important tool in astrophysics * Combines polarization theory, instrumentation, analysis techniques and the associated astrophysical processes * Written by leaders in the field