  We study the optical properties of highly anisotropic quantum dot structures
(quantum dashes) characterized by the presence of two trapping centers located
along the structure. Such a system can exhibit some of the properties
characteristic for double quantum dots. We show that sub- and super-radiant
states can form for certain quantum dash geometries, which is manifested by a
pronounced transfer of intensity between spectral lines, accompanied by the
appearance of strong electron-hole correlations. We also compare exciton
absorption spectra and polarization properties of a system with a single and
double trapping center and show how the geometry of multiple trapping centers
influences the optical properties of the system. We show that for a broad range
of trapping geometries the relative absorption intensity of the ground state is
larger than that of the lowest excited states, contrary to the quantum dash
systems characterized by a single trapping center. Thus, optical properties of
these structures are determined by fine details of their morphology.
