A SEMIEMPIRICAL MODEL FOR ELECTROABSORPTION IN GAAS/ALGAAS MULTIPLE QUANTUM-WELL MODULATOR STRUCTURES

A semi-empirical model for electroabsorption in GaAs/AIGaAs quantum wells is proposed which is simple and has sufficient accuracy to make it suitable as a fast design-tool for multiple quantum well (MQW) optical modulators. The model is based on a higher order perturbation approach which includes all bound solutions of the unperturbed Hamiltonian. To complete the model, semi-empirical relationships are set up for both the zero-field absorption peak and the half-width at half-maximum (HWHM) values of the heavy-hole (hh) exciton. Comparison with extensive experimental data show 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. © 1990 IEEE