Large p-doping offset layer in a p-i-n heterostructure is proposed for Impurity free vacancy disordering (IFVD) quantum-well-intermixing (QWI) in a SOA-integrated EAM. The P-dopant diffusion during QWI can thus be reduced for performing bandgap engineering, leading to high-speed modulation of 30Gb/s and improving modulation efficiency.