Yu Mimura, Kazuhiro Ikeda, Tatsuya Hatano, Takeshi Takagi, Sugio Wako and Hiroshi Matsuura
As a technology for increasing the capacity to meet the growing demand for communications in recent years, dense wavelength-division multiplexing (DWDM) is being implemented in tandem with achieving higher transmission rates on each channel. At next-generation transmission rates of 40 Gbps, it is expected that polarization mode dispersion (PMD) will be the main factor in the deterioration of transmission characteristics. Both first-order PMD and higher-order PMD can affect the performance of a high-speed optical transmission system. A PMD emulator capable of generating PMD up to the second-order is useful in estimating the performance degradation due to PMD and in optimizing the devices that compensate for this type of degradation. The present work is a programmable device based on variable Faraday rotators (VFRs) that is capable of emulating first-order and two components of second-order PMD. Various PMD conditions can be generated by the emulator and the measured values agree with theoretical simulations. Further, we propose a much simpler configuration for the PMD compensator (PMDC) with higher-order PMD canceller (HOPC), unifying the monitor sections of the PMDC and HOPC into one power monitor. Test results for our configuration in a 10-Gbps evaluation system are also reported.