Abstract
A technique for monitoring both the pulse carving misalignment and π phase shift in a return-to-zero (RZ) differential phase-shift keying (DPSK) system based on a phase modulator is proposed and demonstrated. By monitoring the mean-power variation of a hybrid local oscillation lightwave with the modulated signal lightwave without any deliberated control, the technique can provide the information on pulse carving misalignment and phase modulation index simultaneously, as the power variation reflects the asymmetric distribution of RZ-DPSK in a signal constellation diagram. It is characterized as transparent to signal bit rate, central wavelength, and absolute power level. Both the simulation and experiment results show that more than bit duration misalignment and phase shift deviated from π can be detected.
© 2008 Optical Society of America
Full Article | PDF ArticleMore Like This
Xiaolin Li, Fan Zhang, Xiaoru Zhang, Dechao Zhang, Zhangyuan Chen, and Anshi Xu
Opt. Express 16(3) 2056-2061 (2008)
J.-Y. Yang, L. Zhang, Y. Yue, V. R. Arbab, A. Agarwal, L. Paraschis, and A. E. Willner
Opt. Lett. 34(7) 1006-1008 (2009)
Fan Zhang, Christian-A. Bunge, and Klaus Petermann
Opt. Lett. 31(8) 1038-1040 (2006)