Signed frequency offset measurement for direct detection DPSK system with a chromatic dispersion offset

Jian Zhao, Pak Tao Lau, Khurram Karim Qureshi, Chao Lu, X. R. Ma, Hwa Yaw Tam, Ping Kong Alexander Wai

Research output: Journal article publicationJournal articleAcademic researchpeer-review

2 Citations (Scopus)


We demonstrated a method for the measurement of signed frequency offset between optical source and delay interferometer (DI) for 10Gb/s DPSK signals based on asynchronous delay-tap sampling technique with a chromatic dispersion (CD) offset. The demodulated DPSK signals show asymmetrical property and amplitude shoulder appears on the waveforms with frequency offset and a fixed CD offset together. The delay-tap sampling scatter plots also show the asymmetry related to the asymmetrical signal distortion. Our proposed method cannot only realize the measurement of the magnitude of frequency offset but also the polarity. The measurement range is from -2GHz to + 2GHz and the sensitivity can reach ± 100MHz. The simulation and experimental results are demonstrated and in good agreement.
Original languageEnglish
Pages (from-to)23829-23836
Number of pages8
JournalOptics Express
Issue number23
Publication statusPublished - 8 Nov 2010

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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