  The dynamics of modes and their states of polarizations in multimode fibers
as a function of time, space, and wavelength are experimentally and
theoretically investigated. The results reveal that the states of polarizations
are displaced in Poincare sphere representation when varying the angular
orientations of the polarization at the incident light. Such displacements,
which complicates the interpretation of the results, are overcome by resorting
to modified Poincare spheres representation. With such modification it should
be possible to predict the output modes and their state of polarization when
the input mode and state of polarization are known.
