Electrorefractive Coupled Quantum Well Modulators: Model and Experimental Results

Theoretical modeling of InP coupled-quantum-well electroabsorptive and electrorefractive modulators is presented. Key mathematical transformations are developed that allow efficient computation of electrorefraction for a complex multiparameter coupled quantum well structure. The model is realized in the Mathematica platform and is used to simulate the impact of well and barrier composition and thickness on Mach-Zehnder modulator performance. The advantage of using coupling between quantum wells is quantified and in addition, it is shown that linewidth broadening is a key input to the model and has a critical impact on modulator performance. The model is compared to experimental data from phase modulators and Mach-Zehnder intensity modulators.