A quantum dot laser operates on a quantum dot ground-state optical transition. The laser has a broadband (preferably .gtoreq.15 nm) spectrum of emission and a high output power (preferably .gtoreq.100 mW). Special measures control the maximum useful pump level, the total number of quantum dots in the laser active region, the carrier relaxation to the quantum dot ground states, and the carrier excitation from the quantum dot ground states. In one embodiment, a spectrally-selective loss is introduced into the laser resonator in order to suppress lasing on a quantum dot excited-state optical transition, thereby increasing the bandwidth of the emission spectrum.