Kazuhiro Ikeda, Takeshi Takagi, Tatsuya Hatano, Hajime Kazami, Yu Mimura and Hiroshi Matsuura
As a technology for increasing the capacity to meet growing communications demand in recent years, dense wavelength-division multiplexing (D-WDM) is being implemented in tandem with achieving higher transmission rates on each channel. At next-generation transmission rates of 40 Gbps, polarization mode dispersion (PMD) is thought to be the main factor in the deterioration of transmission characteristics. There is thus a need for endless tracking polarization controllers as constituents of PMD compensators. Here we report the development of an endless tracking polarization controller using variable Faraday rotators (VFRs), which offers superior optical characteristics and the promise of higher reliability.