Suppression of stimulated Brillouin scattering by using RZ-DPSK format in long-span unrepeatered transmission system

This paper shows that long unrepeatered transmission using the RZ-DPSK format and large Aeff fiber offers better Q factors and higher Brillouin threshold than is possible with the CS-RZ-OOK format. The maximum Q factors possible with the RZ-DPSK format and the CS-RZ-OOK format were 19.8 dB at the signal input power of 21 dBm, and 16.1 dB at the signal input power of 19 dBm, respectively. The Brillouin threshold of the RZ-DPSK format and the CS-RZ-OOK format were 28 dBm and 18 dBm, respectively. This result shows the advantage of applying the RZ-DPSK format to long-span unrepeatered transmission using high signal input powers. We also showed that the RZ-DPSK format offers good transmission performance in 10.66 Gbit/s single channel 470 km unrepeatered transmission.