This paper reviews the fundamental concepts and basic theory of polarizatio
n mode dispersion (PMD) in optical fibers. It introduces a unified notation
and methodology to link the various Views and concepts in Jones space and
Stokes space. The discussion includes the relation between Jones vectors an
d Stokes vectors, rotation matrices, the definition and representation of P
MD vectors, the laws of infinitesimal rotation, and the rules for PMD vecto
r concatenation.