| 摘要 |
<p>A method of compensating the polarisation mode dispersion (PMD) of an optical transmission path (12) carrying clocked digital data traffic involves modulating the state of polarisation (SOP) of the light launched into the transmission path, and employing consequential frequency components in an electrical signal detected at the far end of the transmission path to regulate the birefringence of a polarisation state controller portion (30) of a birefringent element inserted between the transmission path and the receiver's photodetector. The SOP modulation, when represented on a Poincaré sphere (40, 50), has an oscillatory rotational component (42) at a frequency f1 about a first axis of the sphere and an oscillatory rotational component (43) at a frequency f2 about a second axis of the sphere that is orthogonal to said first axis, and where f1 NOTEQUAL f2, f1 NOTEQUAL 2f2, and f2 NOTEQUAL 2f1. <IMAGE></p> |
