Within the framework of compact density matrix approach and iterative procedure, a detailed procedure for the calculation of the second-harmonic generation (SHG)susceptibility tensor is given in the electric-field-bia...Within the framework of compact density matrix approach and iterative procedure, a detailed procedure for the calculation of the second-harmonic generation (SHG)susceptibility tensor is given in the electric-field-biased parabolic and semi-parabolic quantum wells (QWs). The simple analytical formula for the SHG susceptibility in the systems is also deduced. Numerical results on typical AlGaAs/GaAs materials show that, for the same effective width,the SHG susceptibility in semi-parabolic QW is larger than that in parabolic QW due to the self-asymmetry of the semiparabolic QW, and the applied electric field can make the SHG susceptibilities in both systems enhance remarkably.Moreover, the SHG susceptibility is also related to the parabolic confinement frequency and the relaxation rate of the systems.展开更多
A detailed procedure for the calculation of the third-harmonic-generation susceptibility tensor is given in special asymmetric quantum wells, and an analytic formula for the third-harmonic-generation susceptibility is...A detailed procedure for the calculation of the third-harmonic-generation susceptibility tensor is given in special asymmetric quantum wells, and an analytic formula for the third-harmonic-generation susceptibility is obtained by the compact density matrix approach and the iterative procedure. Finally, the numerical results are presented for typical GaAs/AlGaAs asymmetric quantum wells. The calculated results show that the origin of the large thirdharmonic-generation susceptibility is due to the increase in asymmetry of the quantum well.展开更多
文摘Within the framework of compact density matrix approach and iterative procedure, a detailed procedure for the calculation of the second-harmonic generation (SHG)susceptibility tensor is given in the electric-field-biased parabolic and semi-parabolic quantum wells (QWs). The simple analytical formula for the SHG susceptibility in the systems is also deduced. Numerical results on typical AlGaAs/GaAs materials show that, for the same effective width,the SHG susceptibility in semi-parabolic QW is larger than that in parabolic QW due to the self-asymmetry of the semiparabolic QW, and the applied electric field can make the SHG susceptibilities in both systems enhance remarkably.Moreover, the SHG susceptibility is also related to the parabolic confinement frequency and the relaxation rate of the systems.
文摘A detailed procedure for the calculation of the third-harmonic-generation susceptibility tensor is given in special asymmetric quantum wells, and an analytic formula for the third-harmonic-generation susceptibility is obtained by the compact density matrix approach and the iterative procedure. Finally, the numerical results are presented for typical GaAs/AlGaAs asymmetric quantum wells. The calculated results show that the origin of the large thirdharmonic-generation susceptibility is due to the increase in asymmetry of the quantum well.