We calculate the electronic structure of nm scale InP islands embedded in
Ga0.51In0.49P. The calculations are done in the envelope approximation
and include the effects of strain, piezoelectric polarization, and mixing among
6 valence bands. The electrons are confined within the entire island, while the
holes are confined to strain induced pockets. One pocket forms a ring at the
bottom of the island near the substrate interface, while the other is above the
island in the GaInP. The two sets of hole states are decoupled. Polarization
dependent dipole matrix elements are calculated for both types of hole states.Comment: Typographical error corrected in strain Hamiltonia