[en] The p-doped twinning superlattice is analysed by the envelope function method. The model devised for this purpose shows its validity on the example of germanium based superlattice. The effective scattering potential at the twinning interface is modeled by a diagonal matrix delta-function potential centered at the interface. Potential strengths are fitted to the energies of bound states of single twinning boundary. The superlattice electronic structure exhibits zero energy gaps as well as folding and anti crossing behavior and agrees very well with the results of pseudopotential calculations. Intersubband optical absorption is also calculated. Each absorption peak is attributed to the specific transition, which obeys appropriate selection rule for the given polarization of the incident light. Relative magnitudes of the absorption coefficient are explained by the band structure anisotropy of germanium. Finally, it is shown that the enhanced scattering due to the symmetry removal in the twinning superlattice may bring considerable benefits in the detection of infrared light (author)