Cross-phase modulation efficiency in offset quantum-well and centered quantum-well semiconductor optical amplifiers

We conduct an experimental study of cross-phase modulation efficiency for semiconductor optical amplifiers with two different active regions-offset quantum-well (OQW) stack and centered quantum-well (CQW) stack. OQW devices exhibit less than 100/spl deg/ phase change, whereas CQW devices are 60% more efficient for the same pump input power, with more than 200/spl deg/ phase change possible. The input wavelength degrades the phase change significantly outside the 30-nm gain bandwidth window.