Simple Multichannel Optical Equalizer Mitigating Intersymbol Interference for 40-Gb/s Nonreturn-To-Zero Signals

We demonstrate a simple dynamic silica-waveguide filter that can significantly improve the performance of 40 Gb/s digital optical systems. It has only two control knobs yet can mitigate impairments caused by transmitter imperfections, receiver imperfections, optical filter narrowing, chromatic dispersion, and polarization mode dispersion. One device can handle many channels simultaneously, provided the channels have similar distortions.