Signed chromatic dispersion monitoring of OOK signal by evaluating the distance ratio of delay tap sampling

We analyze the residual chromatic dispersion (CD) monitoring of non-return-to-zero on-off keying (NRZ-OOK) signals using delay-tap asynchronous sampling. By evaluating the distance ratio of delay-tap plots and using a 0.5-bit optical delay interferometer (ODI), signed residual CD can be monitored accurately via numerical simulations. This CD monitoring method is independent of optical signal-to-noise ratio (OSNR) and polarization-mode dispersion (PMD). The measuring range was around ±900 ps/nm for 10-Gbit/s NRZ-OOK link and ±60 ps/nm for 40 G link, the monitoring error is smaller than 2 ps/nm.