Theoretical analysis of ultrafast InGaAs/GaAs MQW modulators and comparison to experimental devices

A theoretical approach for the analysis of electrooptical InGaAs/GaAs Multiple Quantum Well (MQW) waveguide modulators is presented. A lossy Beam Propagation Method (BPM) is used to describe the optical propagation in lossy media and a quasi-TEM model is used for the "slow-wave" microwave field interacting with the optical beam. Both methods are combined together to form an effective CAD tool for the analysis and design of such electrooptical devices. Characteristic design parameters, such as the optical transmission and the relative modulation, are calculated and shown to be in excellent agreement with the experimental results, demonstrating the feasibility of the theoretical approach.