Dynamic characteristics of high-speed In0.4Ga0.6As/GaAs self-organized quantum dot lasers at room temperature

We have measured the room-temperature modulation characteristics of self-organized In0.4Ga0.6As/GaAs quantum dot lasers in which electrons are injected into the dot lasing states by tunneling. A small-signal modulation bandwidth of f−3 dB=22 GHz is measured. Values of differential gain at 288 K of dg/dn≅8.85×10−14 cm2 and gain compression factor ε=7.2×10−16 cm3 are derived from the modulation data. Extremely low values of linewidth enhancement factor α∼1 and chirp <0.6 Å were also measured in the devices.