Recent advances in semiconductor optical amplifiers and their applications

The authors review recent advances in SOAs (semiconductor optical amplifiers) and some of their applications. SOAs are under rapid development to achieve polarization independent gain, low facet reflectivities, good coupling to optical fibers, and high saturation power. The package SOA can be made compact and possibly inexpensive, but its main advantage is the potential for optoelectronic integration. SOAs may be used as boosters and preamplifiers, but in the case of multichannel systems attention must be given to the inherent nonlinear behavior that is due to the short lifetime of the injected carrier density. On the other hand, short lifetime will allow SOAs to be used as gates, modulators, detectors, and frequency converters for signals with gigabit per second data rates.<>