Design of polarization independent InGaAs/InGaAlAs coupled quantum well structure in 1.55 mu m wavelength region

摘要

A novel polarization independent InGaAs/InGaAlAs quantum well (QW) structure in the 1.55 mum wavelength region is proposed. A coupled QW structure with tensile strain in the QW and/or barrier region is considered for the reduction of the optical gain difference between TE and TM modes in the wide spectral range. A triple-coupled QW structure with alternative strain (tensile/compressive/tensile) is found to be the most effective in reducing the polarization gain difference. This is because the transition strength difference of each polarization is reduced by energy states coupling. The optimized triple-coupled QW structure shows polarization independence for wide carrier density and wavelength range, which is suitable for polarization independent operation of QW based semiconductor devices, such as semiconductor optical amplifiers. References: 11