Planar lightwave circuit dispersion equaliser with a wide operational frequency range

The authors report an integrated-optic dispersion equaliser with an amplitude flattening circuit on a planar lightwave circuit. The equaliser consists of six asymmetrical Mach-Zehnder interferometers cascaded in series. The operational frequency range of the equaliser is successfully extended from 12.6 to 21.2 GHz by amplitude flattening without deteriorating the delay characteristics.