Adaptive gain and channel equalization filters for applications in optical networks

Two dynamically reconfigurable filter components, an adaptive gain flattening filter and a variable channel equalizer are presented. Reconfigurability is obtained via thermo-optic tuning of the cascaded resonant coupler (RC) segments. The devices are realized in high-index contrast SiON technology. The accuracy of the attenuation acropos the full band is around 1 dB, which can be further improved by using more delay line stages.