Experimental equalization of polarization dispersion

A demonstration of the equalization of polarization dispersion in a direct-detection lightwave system is described. Polarization-maintaining fiber was used to generate first-order polarization dispersion, and equalization was achieved by a manually adjustable, analog tapped delay line that equalized the baseband electrical signal at the receiver. At a 1.1 Gb/s rate, a two-tap equalizer reduced the intersymbol interference due to polarization dispersion by more than 20 dB, eliminating a 3-dB eye-closure penalty. The error rate was reduced from 10/sup -6/ to below 10/sup -9/.<<ETX>>