Alpha-factor improvements in high-speed p-doped In0.35Ga0.65As/GaAs MQW lasers.

The authors investigate experimentally for the first time the improvements in the linewidth enhancement factor, Alpha, resulting from simultaneous addition of strain and p-doping in high-speed GaAs-based multiquantum well lasers. The Alpha factor is determined from measured changes in both gain and refractive index as a function of CW bias current, yielding Alpha 3.1 and 1.4 at the threshold lasing wavelength for unstrained GaAs/Al0.25Ga0.75As and p-doped strained In0.35Ga0.65As/GaAs devices, respecitvely.