Linear and nonlinear optical absorption of position-dependent mass oscillators

Abstract

We study the linear $({\alpha }^{(1)})$, nonlinear $({\alpha }^{(3)})$ and total $(\alpha )$ optical absorptions of position-dependent mass oscillators (PDMOs). We consider three mass distributions $(m(x,\lambda ))$ used to describe semiconducting structures; $\lambda$ is a deformation parameter. In the limit $\lambda \to 0$, the three systems describe electrons in a parabolic quantum well. For the system $m_1(x)=m_0/[1+(\lambda x{)}^2{]}^2$ we observe that ${\alpha }^{(1)}(\omega ))({\alpha }^{(3)}(\omega ))$ increases (decreases) with increasing $\lambda$. For $m_2(x)=m_0[1+(\lambda x{)}^2]$ and $m_3(x)=m_0[1+tan{h}^2(\lambda x)]$ the opposite occurs. In the light of the PDMO approach we observe the $m_2(x)$ and $m_3(x)$ systems are very similar, and can not be distinguished by optical transitions between the two lowest electronic levels. We also discussed about the total optical absorption of the systems.