Study and characterization of a new monolithic mode-locked edge-emitting semiconductor quantum dot lasers emitting at 1.26 um are ideal sources for the generation of optical frequency combs for short-reach inter- and intra-data center links. The modal dispersion and gain properties determine the suitability for ultra short optical pulse generation by mode-locking. In this elaborate, as a first step, the power vs. current characteristics, the modal gains and the dispersion properties on InAs/InGaAs single section quantum dot lasers with broad ridge waveguide are experimentally investigated. This analysis focuses on spectrally-resolved gain, temperature dependence and near field investigation, trying to highlight the influences of the different p-doping values, different active region lengths and broad area effects.