Enhanced refractive index change in asymmetrical quantum wells with an applied electric field

We theoretically calculate the electric field induced refractive change index for the ground to first excited state transition in the conduction band of asymmetrical quantum wells. We show that there is a significant change in stark shifts and the refractive index with asymmetry potential. Comparing the results for a square, graded, and step well, it is found that larger refractive index change can be achieved in a step well by a proper choice of the step potential.