Sensitivity of quantum dot semiconductor lasers to optical feedback

Summary form only given. We measure the line-width enhancement factor of quantum dot semiconductor lasers and analyse its impact on the sensitivity to optical feedback. In particular, we show that the line-width enhancement factor can be relatively large due to both inhomogeneous broadening but also due to the plasma effects from non-resonant carriers. However, the devices have a low sensitivity to optical feedback mainly due to the strong damping of the relaxation oscillations that can be associated with gain saturation.