Optical second-harmonic generation in two electromagnetically coupled two-level quantum wells

Starting from an integral equation for the local electric field, the second-harmonic generation from two electromagnetically coupled quantum wells is calculated. Each of the two quantum wells is assumed to have only two bound levels; and particular emphasis is devoted to a study of the inter-subband dynamics. In the wake of a calculation of the p-polarised fundamental field the corresponding second-harmonic field is determined. By adopting the simple infinite-barrier model analytical results are obtained for the fields, and the conversion efficiency for the nonlinear process is obtained. Various numerical results showing the importance of the radiative coupling between the wells are reported.