Nonlinear optical properties of GaN/AlN constant total effective radius multi-wells quantum rings

In this study, we investigate the effect of the number of wells and ring thickness on the third-order absorption coefficient as well as figure dipole matrix elements and oscillator strength of multi-wells GaN/AlN constant total effective radius multi-wells quantum rings (CTER-MWQRs). We show that order of the nonlinearity decreases by increasing of the number of wells by going from 1 to 2 numbers of wells and increases by going from 2 to 10 numbers of wells. This is just against the effect of the inner quantum ring radius R-0 values, since order of the nonlinearity increases by increasing of the R-0 value by going from 0 nm to 5 nm and decreases by going from 5 nm to 30 nm for an eight wells CTER-MWQRs. Finally, we prove that, if we want to construct a system which has a special peak position, changing of the R-0 values is more efficient than changing of the number of wells.