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 polarization dependent loss are reduced by modulating the state of polarization (SOP) of an optical signal being launched into the transmission path periodically between first and second states of polarization of at least one pair of orthogonal states of polarization. Ideally, the launched modulated signal should spend equal time intervals in both states of the orthogonal pair. In one exemplary embodiment, the SOP is modulated such that it moves along a great circle on the Poincaré sphere. In another exemplary embodiment, the SOP is modulated such that it traces a complete great circle on the Poincaré sphere. In a preferred embodiment, a complete great circle is traced at a uniform speed on the Poincaré sphere.