Optimization of nonlinear optical rectification in quantum wells using the supersymmetric quantum mechanics

Abstract

A systematic procedure is proposed for optimized design of semiconductor quantum well structures that provide maximal values of the resonant optical rectification coefficient. It relies on employing supersymmetric quantum mechanics to vary the starting potential in the isospectral manner, via the variation of a single scalar parameter, in search of the largest available value of the appropriate product of matrix elements (difference of permanent moments times the transition dipole moment squared, in this instance). An example design of the structure matched for the optical rectification of 10.6 mu m (CO2 laser) radiation is presented. It starts from the truncated parabolic potential and delivers a rectification coefficient in excess of the best value reported in the literature. The possibility of realization of optimized structures is also discussed. (C) 1997 Elsevier Science B.V.