Spatial hole burning and multimode generation threshold in quantum-dot lasers

The multimode generation threshold in quantum-dot (QD) lasers is calculated as a function of the parameters of structure and temperature. Thermally ex cited escapes of carriers away from QDs are shown to control the multimode generation threshold. A decrease in the QD size dispersion is shown to incr ease considerably the relative multimode generation threshold. The maximum tolerable QD size dispersion and the minimum tolerable cavity length, at wh ich the lasing is possible to attain, are shown to exist. Concurrent with t he decrease of threshold current, the reduction of multimode generation thr eshold is shown to occur with decrease of temperature. (C) 1999 American In stitute of Physics. [S0003-6951(99)02909-5].