Chromatic dispersion monitoring technique employing SOA spectral shift in 40Â Gbit/s system

An all-optical online chromatic dispersion monitoring technique in 40 Gbit/s system by using of the spectral shift in the semiconductor optical amplifier (SOA) is demonstrated. Spectrum components on the long-wavelength side of 40 Gbit/s signal after passing the SOA are extracted for the dispersion monitoring. The range of monitoring can reach ±60 ps/nm, and the accuracy of monitoring is less than 5 ps/nm.