ABSTRACT
Photonic integrated circuits incorporate guided-wave structures, which implement several functions, such as light generation, modulation, switching, and detection, on a single semiconductor substrate. Integration of some of these functions on a single substrate improves the effectiveness and reliability of their interconnection and lowers the overall manufacturing cost. The use of semiconductor substrates such as GaAs or InP allow growth of as many as a few hundreds of planar layers having different compositions and electrical carrier concentrations on a single substrate. This capability, along with recent advances in fabrication, such as the use of etch-stop layers, localized growth and doping, and in situ processing, have allowed demonstration of some sophisticated photonic integrated-circuit structures.
