Spectrotemporal response of 1.3 μm quantum-dot lasers

We report the spectrotemporal measurements on 1.3 μm quantum-dot lasers with picosecond time resolution. The relaxation oscillations of the various mode groups monitored separately are identical and thus allow us to examine the spectrally integrated transient of the laser pulse for its characteristics. A modulation bandwidth of 2.3 GHz at room temperature is determined, demonstrating the potential of high-speed operation of these devices at wavelengths relevant for optical data transmission. The differential gain at room temperature was measured to be $g^{\prime }{\text{=1×10}}^{\text{−15}}\hspace{0.17em}{\mathrm{cm}}^2,$ the gain compression factor is ${\text{ε=1×10}}^{\text{−15}}\hspace{0.17em}{\mathrm{cm}}^3.$