Tailoring the terahertz absorption in the quantum wells

In this paper the optical properties of an inverse parabolic quantum well mixed with a square quantum well has been investigated. The Schrödinger equation has been solved using the numerical method and all the eigen-energies and wave functions are obtained. Furthermore, using the density matrix approach and perturbation method, the absorption coefficients and refractive index changes have been calculated and analyzed. The results show that for appropriate values of quantum well parameters the absorption coefficient peak lies in the terahertz frequency range. Also, the stability of the absorption peak due to small random defects in quantum well is investigated.