A study of the cross-phase modulation (XPM) degradation of differential-phase-shift-keyed (DPSK) signals due to amplitude-shift-keyed signals is performed using pump–probe simulation. Approximate expressions for the contributions of the XPM-induced intensity and phase modulation to the electrical current fluctuations at the differential-phase-exchange-keyed receiver are presented. It is shown that, unlike prior works and similar to intensity-modulated signals, the contribution of XPM-induced intensity modulation is dominant in systems using standard fiber or high residual dispersion.
© 2007 Optical Society of America
Diffraction and Gratings
Original Manuscript: April 23, 2007
Revised Manuscript: August 9, 2007
Manuscript Accepted: August 17, 2007
Published: September 18, 2007
Ruben S. Luís, Benoît Clouet, António Teixeira, and Paulo Monteiro, "Pump-probe analysis of the cross-phase modulation degradation induced by 10 Gbit/s amplitude-shift-keyed signals on 40 Gbit/s DPSK signals," Opt. Lett. 32, 2786-2788 (2007)