Anisotropy coefficients of a Mueller matrix.

Anisotropy coefficients α, β, and γ that describe the type and the relative amount of the three kinds of anisotropy generally present in a Mueller matrix are introduced. Their derivation, algebraic properties, and physical interpretation are discussed. In particular, they are shown to permit a geometrical representation for the anisotropy and polarizing characteristics of a Mueller matrix. Illustrative experimental examples are provided.