  The electronic continuum states of InAs/GaAs semiconductor quantum dots
embedded in a GaAs/AlAs superlattice are theoretically investigated and the far
infrared absorption spectra are calculated for a variety of structures and
polarizations. The effect of a strong magnetic field applied parallel to the
growth direction is also investigated. We predict that the flatness of the
InAs/GaAs dots leads to a far infrared absorption which is almost insensitive
to the magnetic field, in spite of the reorganization of the continuum into
series of quasi-Landau states. We also predict that it is possible to design
InAs/GaAs photoconductors which display very strong in-plane absorption.
