Analysis of polarization independent diffused QW optical amplifiers

The features of polarization independence of optical amplifiers achieved by using diffused QW are discussed. Our theoretical results successfully explain why polarization independence can achieve in the long wavelength tail of the modal gain and absorption coefficient but not at photon energies above the transition edge. This explanation applies to other tensile-strained QW for polarization independent applications. The understanding is crucial for optimizing polarization independent devices.