Comparison between NRZ and duobinary Modulation at 43 gb/s for MLSI-based and DCF-based transmission systems

In this paper, the performance of midlink spectral inversion (MLSI) is compared with the performance of "conventional" dispersion compensation fiber (DCF)-based transmission for two data formats: 43-Gb/s ON-OFF keying nonreturn-to-zero (OOK-NRZ) and 43-Gb/s duobinary. In the MLSI-based system, a polarization-diverse subsystem was used for spectral inversion employing magnesium-oxide-doped periodically poled lithium niobate (PPLN) waveguide technology. The transmission link consists of 8 /spl times/ 100 km standard single-mode fiber (SSMF) using erbium-doped fiber amplifiers (EDFAs) for amplification. Compared to the DCF-based system, it is seen that the MLSI-based configuration enhances the dispersion tolerance for both the NRZ and the duobinary modulation formats. It is concluded that the combination of the MLSI and the duobinary modulation format yields a highly dispersion-tolerant stable 43-Gb/s transmission system.