Electric field effect on the refractive index changes in a Modified-Pöschl-Teller quantum well

The effect of an applied static field is studied on the optical properties of a quantum well (QW) represented by a Modified Pöschl–Teller potential. This potential allows analytical solution of the eigen-values and eigen-functions which in turn makes the numerical calculation of optical properties quite transparent. In this work, we concentrate on the linear and nonlinear refractive index changes. Comparison of the results using the finite Modified-Pöschl–Teller (MPT) potential with those in the literature using the infinite Pöschl–Teller (PT) potential shows that the main difference between the two potentials is coming from the depth differences of the two wells. The changes in the refractive indices are bigger than those using infinite PT potential. If one wants a larger change in the total refractive index, one should try to reduce the applied electric fields and the optical intensities.

Graphical abstractContribution of the second term in the nonlinear refractive index change as a function of photon energy for various applied electric field values EE, where η=6η=6and the well depth is −0.34eVwith I=1.0MW/cm2.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► We consider an electron in a quantum well modeled by a Modified Pöschl–Teller potential. ► We present a numerical calculation of the wave functions and energy levels of the system. ► The nonlinear optical properties (the refractive index changes) of this system have been investigated.