High speed operation of very low threshold strained InGaAs/GaAs double quantum well lasers

Abstract
Very low threshold current strained In0.2Ga0.8As/GaAs double quantum well buried‐heterostructure lasers have been fabricated by a hybrid metalorganic chemical vapor phase deposition and liquid phase epitaxy regrowth technique. The modulation bandwidths were compared in lasers of different active strip widths, cavity lengths, and facet reflectivities in order to achieve modest high‐modulation bandwidth at low operating current. A 5 GHz 3 dB modulation bandwidth is demonstrated at a current of 2.1 mA in a laser with a threshold current of 0.5 mA.