Semiconductor lasers for WDM systems and beyond

Summary form only given, as follows. The current generation of lightwave transport systems being deployed for transoceanic and terrestial applications has been made possible by key optical devices, both active and passive. These devices include modulators, integrated electro-absorption modulated lasers, multiplexers, demultiplexers, EDFA, high power pump lasers, and fiber devices. To realize the full potential of wavelength division multiplexing (WDM) to build reconfigurable transport networks requires a family of optical network elements. Devices such as configurable add/drop multiplexers, wavelength tunable lasers, optical cross-connects, and transponders are very important. The paper reviews some of these devices.