OPTOELECTRONIC DEVICES HAVE RECEUVED GRET ATTENTION IN RECENT YEARS, AS THEY ARE KEY COMPONENTS OF THE INTERNET AND OTHER OPTICAL COMMUNICATIONS SYSTEM.  OTHER BREAKTHROUGH DEVELOPMENTS FORINSTANCE WITH GaN-based light emitters, also contribute to the increased interest i optoelectronics.  The  complexity of physical  mechanism within such devices makes computer simulation an essential tool f or performance analysis  and design optimization. Advanced software tools have been developed for optoelectronic devices and several commercial software providers have emerged.  These tools enable engineers and scientists to design and understand ever-more sophisticated nanostructured devices.