This book provides a self-contained presentation of optical methods used to measure the structure and dynamics of complex fluids subject to the influence of external fields. Such fields (hydrodynamic, electric and magnetic) are commonly encountered in both academic and industrial research, and can produce profound changes in the microscale properties of liquids comprised of polymers, colloids, liquid crystals or surfactants. Starting with the basic Maxwell field equations, this book and Mueller calculus, and then covers the transmission, reflection and scattering of light in anisotropic materials. Spectroscopic interactions with orientated sytems such as absorptive dichroism, small wide angle light scattering, and Raman scattering are discussed. Applications of these methods to a wide range of problems in complex fluid dynamics and structure are presented, along with selected case studies on particular studies chosen to elucidate the range of techniques and materials that can be studied.