New Asymmetric Quantum Well Traveling-Wave Electroabsorption Modulator with Very Low Insertion Loss and High Extinction Ratio

In this paper, we propose a novel InGaAlAs asymmetric intra-step-barrier coupled double strained quantum well (AICD-SQW) structure at 1.55 mum. This structure shows that electroabsorption modulator (EAM) properties such as large change in absorption, high extinction ratio, large Stark shift, very low insertion loss, and better figure of merit are possible to be achieved simultaneously as compared with Intra-step quantum well (IQW). In the analysis, the exciton equation in momentum space is solved numerically using Gaussian quadrature method to obtain exciton binding energy and oscillator strength. The asymmetric quantum well structure Hamiltonian is numerically solved by transfer matrix method (TMM) to obtain the electron and hole subband energy levels taking in to account the strain. The electroabsorption coefficient is calculated for different applied electric field for TE input light polarization. The EAM parameters such as extinction ratio, insertion loss and the figure of merit are calculated and the performances of AICD-SQW are compared with IQW.