  Tunnel-injection lasers promise advantages in modulation bandwidth and
temperature stability in comparison to conventional laser designs. In this
paper, we present results of a microscopic theory for laser properties of
tunnel-injection devices and a comparison to a conventional quantum-dot laser
structure. In general, the modulation bandwidth of semiconductor lasers is
affected by the steady-state occupations of electrons and holes via the
presence of spectral hole burning. For tunnel-injection lasers with InGaAs
quantum dot emitting at the telecom wavelength of 1,55$\mu$m, we demonstrate
that the absence of spectral hole burning favors this concept over conventional
quantum-dot based lasers.
