An optical device including a beam splitter, polarization controller, and beam
combiner is described. In some embodiments, the beam splitter and beam combiner
are provided in a single element. An incoming light beam is split into two beams
with different polarization components. The polarization of one or both of the
beams is rotated using one or two polarization controllers such as fiber squeezers.
The beams are then combined, so that a portion of each of the beams is provided
to an output. The polarization dependent loss of the device can then be controlled
by controlling the polarization rotation. In some embodiments, the rotation is
dynamically controlled.