  In this work we consider a current carrying two level quantum dot(QD) that is
coupled to a single mode phonon bath. Using self-consistent Hartree-Fock
approximation, we obtain the I-V curve of QD. By considering the linear
response of our system to an incoming classical light, we see that depending on
the parametric regime, the system could have weak or strong light absorption or
may even show lasing. This lasing occurs at high enough bias voltages and is
explained by a population inversion considering side bands, while the total
electron population in the higher level is less than the lower one. The
frequency at which we have the most significant lasing depends on the level
spacing and phonon frequency and not on the electron-phonon coupling strength.
