Abstract

An analytic model for interchannel four-wave mixing (FWM) is developed for return to zero differential phase shift keying (RZ-DPSK) single span transmission including interchannel walk-off for degenerate FWM (D-FWM) and nondegenerate FWM (ND-FWM). The model is verified by simulations and reasonable agreement is obtained for a 10-Gb/s single span link. Results are presented for different channel spacing, launch pulse duty-cycle, and launch power. The model is strictly valid for systems with low fiber dispersion as it ignores dispersion related pump pulse distortion. It is found that the walk-off effect makes a significant contribution to the detected unfiltered FWM noise and this contribution is mostly concentrated at high frequencies determined by the channel spacing alone. The contribution of the walk-off and its frequency content is understood in terms of intracollision and intercollision interference. In the typical situation when a sub-bit-rate electrical low-pass filter is used, the walk-off effect is effectively removed for all types of FWM. The analytic model is validated by comparing to split-step-Fourier (SSF) simulations. Extension to the general case of multiple FWM lines is considered. It is found that the FWM noise standard deviation is 2 times smaller for RZ-DPSK as compared to that for return to zero on-off keying (RZ-OOK) at the same average launch power for a system with 25-GHz channel spacing.

© 2008 IEEE

Optical phase erasure based on FWM in HNLF enabling format conversion from 320-Gb/s RZ-DQPSK to 160-Gb/s RZ-DPSK

Guo-Wei Lu and Tetsuya Miyazaki
Opt. Express 17(16) 13346-13353 (2009)

All-optical parallel NRZ-DPSK to RZ-DPSK format conversion at 40 Gb/s based on XPM effect in a single SOA

Yu Yu, Bingrong Zou, Wenhan Wu, and Xinliang Zhang
Opt. Express 19(15) 14720-14725 (2011)

Phased-array cancellation of nonlinear FWM in coherent OFDM dispersive multi-span links

Moshe Nazarathy, Jacob Khurgin, Rakefet Weidenfeld, Yehuda Meiman, Pak Cho, Reinhold Noe, Isaac Shpantzer, and Vadim Karagodsky
Opt. Express 16(20) 15777-15810 (2008)

Performance analysis of 20Gb/s RZ-DPSK non-slope matched transoceanic submarine links

Brendan Slater, Sonia Boscolo, Terence Broderick, Sergei K. Turitsyn, Ronald Freund, Lutz Molle, Christoph Caspar, Jörg Schwartz, and Stuart Barnes
Opt. Express 15(17) 10999-11007 (2007)

All-optical 40 Gbit/s CSRZ-DPSK logic XOR gate and format conversion using four-wave mixing

Jian Wang, Qizhen Sun, and Junqiang Sun
Opt. Express 17(15) 12555-12563 (2009)