NRZ-DPSK and RZ-DPSK Signals Signed Chromatic Dispersion Monitoring Using Asynchronous Delay-Tap Sampling

• Published in: Journal of lightwave technology Vol. 27; no. 23; pp. 5295 - 5301
• Main Authors: Jian Zhao, Zhaohui Li, Dawei Liu, Linghao Cheng, Chao Lu, Tam, H.Y.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.12.2009; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Chromatic dispersion; Chromatic dispersion (CD); Coding, codes; Delay; Differential phase shift keying; differential phase-shift keying (DPSK); Dispersions; Exact sciences and technology; Information, signal and communications theory; Keying; Light scattering; Modulation, demodulation; Monitoring; Monitors; Optical distortion; optical performance monitoring (OPM); Optical scattering; Particle scattering; Polarity; Radio frequency; Sampling; Sampling methods; Sampling, quantization; Shoulders; Signal and communications theory; Telecommunications and information theory; Performance evaluation; RZ code; Chromatic dispersion; Interferometer; differential phase-shift keying (DPSK); Monitor; Simulation; optical performance monitoring (OPM); NRZ code; Delay time; Differential phase shift keying; Sampling; Signal distortion; Monitoring; Chromatic dispersion (CD); Demodulation
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2009.2031610

In this paper, we demonstrated a signed chromatic dispersion (CD) monitoring method of 10 GHz nonreturn-to-zero differential phase-shift keying (NRZ-DPSK) and return-to-zero differential phase-shift keying (RZ-DPSK) signals by using asynchronous delay-tap sampling and an imperfect tuned delay interferometer. This method could monitor not only the value but also the polarity of residual CD. The demodulated signals show amplitude shoulders on the rising edge or the trailing edge with CD accumulation. Delay-tap sampling scatter plots could reflect this signal distortion by a unique characteristic and realize the signed CD monitoring. The monitoring range can be up to plusmn400 and plusmn720 ps/nm for NRZ-DPSK and RZ-DPSK signals, respectively. Simulation and experimental results are also proposed.