Internal Strain of Self-Assembled InxGa1-xAs Quantum Dots Calculated to Realize Transverse-Magnetic-Mode-Sensitive Interband Optical Transition at Wavelengths of 1.5 µm bands

We calculated the interband optical transition energies in self-assembled In x Ga1-x As quantum dots on InP as functions of the strain, composition, and height of dots on the basis of the k·p perturbation theory. We found that a transverse-magnetic (TM)-mode-sensitive optical transition at wavelengths in the range from 1.5 to 1.6 µm is achieved due to the light-hole valence band when the crystal lattice is expanded in the same direction of growth as the in-plane lattice matched to the substrate at x≤0.4, or when the lattice is compressed in the growth direction with the in-plane lattice relaxed at x≥0.6. We propose barrier structures covering the dots in order to realize these conditions, leading to TM-mode-sensitive quantum dots for polarization-independent optical amplifiers.