Chromatic dispersion measurement using single sideband spectrum phase difference detection for OOK signal link

In this paper, we theoretically and experimentally demonstrated the residual chromatic dispersion (CD) measuring of 10Gbit/s NRZ and 40Gbit/s NRZ/RZ links by using a novel single sideband (SSB) spectrum phase difference detection technology. This method can differentiate positive and negative residual CD of the fiber link, the measuring range is dependent on frequency difference (FD) of two local oscillator (LO) and the FD can be adjusted up to CD range. This method is independent on data rate for intensity modulation direct detection (IM/DD) links. In condition of FD of 4 GHz, the measuring range was around ± 1000 ps/nm and resolution was better than 5 ps/nm for 10G NRZ link.

Signed chromatic dispersion monitoring of 100Gbit/s CS-RZ DQPSK signal by evaluating the asymmetry ratio of delay tap sampling

In this paper, we theoretically and experimentally demonstrated the residual chromatic dispersion (CD) monitoring of 100-Gbit/s carrier suppress return-to-zero differential quadrature phase shift keying (CS-RZ DQPSK) signals by evaluating the asymmetry ratio of delay tap asynchronous sampling. This scheme can easily differentiate the positive and negative residual CD of the fiber link. The resolution of this scheme is better than 8 ps/nm and the measurable range is around +/- 24 ps/nm for 100 Gbit/s CS-RZ DQPSK signals. We can also simultaneously realize both signed CD monitoring and demodulation of CS-RZ DQPSK signal based on only one demodulator.