摘要 |
An improved digital differential group delay (DGD) controller is capable of producing variable DGD used to compensate for DGD in a fiber optic link in real time. The DGD controller comprises one or more sets of a polarization modulator optically coupled with a fixed delay component, such as a birefringent plate. Each set provides an amount of DGD compensation. By controlling the number of stages in the controller, the amount of DGD compensation provided by each stage, and which stages are placed in the OI/i state, the total amount of DGD compensation provided by the digital DGD controller can be varied. |