Reduction of interferometric optical crosstalk using phase-scrambling technique

We discuss an interferometric crosstalk reduction concept in optical WDM ne tworks by introducing phase dithering in optical signals. The phase ditheri ng is generated through a phase modulator, driven with filtered noise spect ra. An IM/DD optical transmission scheme is used to experimentally verify t he effects of this reduction concept. Crosstalk and signal exhibit a worst case condition, namely, its wavelength and state of polarization are aligne d. Experimental data show that a reduction of 7 dB for crosstalk requiremen t could be achieved with help of a phase-scrambling technique. (C) 1999 Joh n Wiley & Sons, Inc.