Abstract: A monolithically integrated electroabsorption modulated laser having a ridge waveguide structure, has lateral ion implantation. The integrated device has a laser section and a modulator section. The modulator section has ion implanted regions adjacent to the waveguide ridge. The implanted regions penetrate through the top cladding layer to reduce capacitance within the intrinsic active core of the reverse biased modulator and allow a shallow etched ridge waveguide structure to be used for the modulator. The device provides good optical coupling, efficient manufacturing, and good high power performance.