Degenerate four waves mixing in multilayer nanoshell

We will present a detailed investigation of intersubband transitions process in core-multi shells quantum dots. The confined wave functions and eigenenergies of electrons in quantum dots have been calculated under the effective-mass approximation by solving a three-dimensional Schrodinger equation. Excellent dependence is found between size effects, time relaxation and degenerate four wave mixing (DFWM). We found that the enhancement of the thickness layers lead to strongly enhancement in peak value of DFWM.