A semi-empirical model for electroabsorption in GaAs/AlGaAs multiple quantum well modulator structures

A semiempirical model for electroabsorption in GaAs/AlGaAs quantum wells that is simple and has sufficient accuracy to make it suitable as a fast design tool for multiple quantum well (MQW) optical modulators is proposed. The model is based on a higher-order perturbation approach which includes all bound solutions of the unperturbed Hamiltonian. To complete the model, semiempirical relationships are set up for both the zero-field absorption peak and the half-width at half-maximum (HWHM) values of the heavy-hole exciton. Comparison with extensive experimental data shows a remarkable agreement for a range of wells between 5 and 20 nm and for photon energies on the long wavelength side of the absorption peak. These wavelength and well-size ranges coincide with those needed for practical design. >