A simple scheme for polarization insensitive four-wave mixing in semiconductor optical amplifiers

A simple scheme for polarization insensitive four-wave mixing (FWM) in semiconductor optical amplifiers (SOAs) is proposed, which utilizes just one conventional polarization-insensitive SOA and one input pump wave. The technique would be efficient in practical applications for frequency shifts about 0.5 THz for a device length of say 200 μm. The polarization insensitive operating principle of the FWM type is analyzed using an improved space-averaged model for describing FWM of copropagating and counterpropagating optical waves.