Limits to determination of polarization independence in SOAs

Polarization independence is an important property in some applications of the semiconductor optical amplifier, in particular when amplifying polarization multiplexed signals. The accurate determination of polarization dependent gain (PDG) is far more complicated than the determination of polarization dependent loss in passive components, due to the presence of amplified spontaneous emission and the danger of round-trip reflections. We will discuss factors limiting precise measurement of PDG.