APPARATUS AND METHOD EMPLOYING FAST POLARIZATION MODULATION TO REDUCE EFFECTS OF POLARIZATION HOLE BURNING AND/OR POLARIZATION DEPENDENT LOSS

摘要

The effects of polarization dependent hole burning and/or polarizationdependent loss are reduced by modulating the state of polarization (SOP) of anoptical signal being launched into the transmission path periodically between firstand second states of polarization of at least one pair of orthogonal states ofpolarization. Ideally, the launched modulated signal should spend equal timeintervals in both states of the orthogonal pair. In one exemplary embodiment, theSOP is modulated such that it moves along a great circle on the Poincare' sphere. Inanother exemplary embodiment, the SOP is modulated such that it traces a completegreat circle on the Poincare' sphere. In a preferred embodiment, a complete greatcircle is traced at a uniform speed on the Poincare' sphere.