Strained InGaAsP multi-quantum-well structures for InP-based wide linewidth and polarization-insensitive semiconductor optical amplifiers

Abstract

We have calculated the band structure of 1.55 μm InGaAsP/InGaAsP multi-quantum-well structures using Lüttinger–Kohn Hamiltonian taking into account the strain in the quantum wells (QWs) and barriers, and the confinement in the quantum wells. Using the calculated dispersion curves and oscillator strength between the different interband transitions, we have determined the optical gain in TE and TM mode and the spontaneous amplified emission as a function of injected carrier density in devices composed of quantum wells with different thicknesses. We find that an optical gain linewidth larger than 130 nm with a TE/TM polarization dependence lower than 1 dB can be obtained using a three-quantum-well In 0.53Ga 0.47As 0.96P 0.04/InGaAsP active layer with quantum well thicknesses of 10, 14 and 19 nm.