Adaptive distortion compensation with integrated optical finite impulse response filters in high bitrate optical communication systems

In high-bit-rate optical transmission systems, distortions due to dynamic chromatic dispersion, polarization mode dispersion, and power changes are larger than the distortion tolerances of the system. To meet the tolerances and the desired quality of service, an adaptive equalizer is necessary. We demonstrate the capabilities of planar lightwave circuit integrated optical finite impulse response filters for mitigating distortions of the transmission channel, and we investigate two adaptive equalization approaches. The first approach uses an adaptive feedback generated from electrical spectrum monitoring; the second one uses intersymbol interference minimization with a least mean square error algorithm. We successfully demonstrated adaptive equalization of chromatic dispersion, self-phase modulation, and polarization mode dispersion, as well as combinations of these distortions.