Extended ground-state and excited-state emission-state control in a mode-locked two-section quantum dot laser

In this paper, state-of-the-art research on two-state passive mode-locking of InAs/(In)GaAs quantum dot lasers is reviewed with a focus on the influence of extended absorber biasing conditions on the two quantized emission-states of a strongly inhomogeneously broadened quantum dot laser. We start with the recently demonstrated state-selectivity of ground-state, joint ground- and excited-state and then sole excited-state emission by a resistor Self-Electro-Optical Effect configuration. This regime is then extended towards the reverse-bias regime giving access to both excited-state and joint ground- and excited-state emission and to higher laser output power. Finally, we find an excellent accordance of the emission-states at the boundary of the two regimes. The occurrence and evolution of the emission-states in dependence on the biasing conditions are explained qualitatively.