All-optical tunable wavelength shifting of a 128-Gbit/s 64-QAM signal

Wavelength shifting of a 21.4-Gbaud 64-QAM signal is achieved using Bragg scattering with dither-free pumping in a longitudinally stressed highly nonlinear silica fiber. Three wavelengths over a 10-nm tuning range centered on a 24-nm shift are demonstrated with a penalty of less than 2 dB at a BER of 10 -3 .