Design and ASE characteristics of 1550-nm polarization-insensitive semiconductor optical amplifiers containing tensile and compressive wells

The polarization dependence of 1550-nm semiconductor optical amplifiers (SO A's) containing tensile and compressive wells has been investigated both th eoretically and experimentally, Our model to predict the polarization-resol ved (TE and TM) gain spectra of these structures has been confirmed by ampl ified spontaneous emission measurements, It is found that there can be appr eciable carrier redistribution between the two types of wells when the tens ile layers have the large thickness (greater than 100 Angstrom) needed for gain at wavelengths around 1550 nm, This carrier redistribution can signifi cantly modify the ratio of the gains for different polarizations, in partic ular, decreasing the TM gain with respect to the TE gain, and, hence, is an important design consideration. We use our model and experimental data to explore design criteria for 1550-nm polarization-independent SOA's.