Small-signal modulation and differential gain of single-mode self-organized In0.4Ga0.6As/GaAs quantum dot lasers

We report small-signal modulation bandwidth and differential gain measurements of a single-layer self-organized In0.4Ga0.6As/GaAs quantum dot laser grown by molecular beam epitaxy. The 3 dB bandwidth of single-mode ridge waveguide lasers was measured to be 7.5 GHz at 100 mA under pulsed measurements, demonstrating the possibility of high speed operation of these devices. The differential gain was measured to be 1.7×10−14 cm2.