High speed Si-based optical modulator for on-chip optical interconnects

A modulation-doped SiGe-Si multiple quantum well modulator (MD-MQW) embedded in a reverse biased PIN junction is described. Experimental and theoretical results show that the optical index variation can be achieved by plasma-dispersion effect associated to carrier depletion. Interferometric integrated structures proper to transform the obtained phase modulation into amplitude modulation are presented, and the main properties of the optical modulator are evaluated, including intrinsic rapidity, contrast ratio and insertion losses.