Ultra high-speed data signals with alternating and pairwise alternating optical phases

We demonstrate two 160-Gb/s modulation formats that posses the same intensity pulse profile but differ regarding their phase coding. We analyze the nonlinear transmission properties of both coherent modulation formats by experimental and analytical investigations. The results show that the pairwise alternating phase coded carrier suppressed return-to-zero (PAP-CSRZ) signal outperforms the conventional CSRZ format. Our modulation technique is even applicable at higher speed as demonstrated with the generation of the first CSRZ signal at a record rate of 320 Gb/s.