Linear and nonlinear optical properties in quantum wells

Abstract

In this paper, the linear and nonlinear optical properties, especially the optical rectification (OR), the second-harmonic generation (SHG) susceptibility, the third-harmonic generation (THG) susceptibility, the optical absorption coefficients (OACs), and the refractive index changes (RICs) of GaAs-AlGaAs semi-parabolic well (SPW) are studied in detail utilizing the compact density matrix approach and iterative procedure. The states of electron in the SPW with electric field are obtained utilizing the techniques of the displacement harmonic-oscillator and the envelope wave-function. Our results reveal that the confinement frequency, the electric field, the relaxation time, and the incident field strength have considerable influences on the optical properties of the SPW. If it is desired to obtain the OR, SHG, THG, OAC, and RIC with large values, then a relatively weaker incident field strength and confinement frequency, as well as a relatively stronger electric field intensity, should be chosen. If the optical strength is relatively large, then the effect of the nonlinear (third-order) term is important and cannot be neglected when investigating the non-linear optical properties in the SPW. The semiparabolic well is a promising candidate for these properties.