Power transients control in transparent WDM networks

A main concern in a reconfigurable WDM networks is to control the amplifier power transients caused by channel reconfiguration or even network failure/recovery. A simple and low cost solution is to use optical gain clamping (OGC) technique. We present efficient OGC-amplifier configuration with variable gain control insensitive to transients. We show experimental results on a new optical-gain-clamping solution where the whole ring network acts as a laser cavity. We demonstrate that recirculating amplified-spontaneous-emission noise may clamp the network gain. The spectral-hole-burning (SHB) offset limitation is also addressed. In addition we describe a recent transparent network testbed based on OGC-EDWA that outperforms the standard OGC-EDFA and suppresses SHB offset.