COMPARISON OF THE QUADRATIC ELECTRO-OPTIC EFFECT IN ZnS /CdSe /ZnS AND CdSe / CdSe /ZnS CYLINDRICAL STRUCTURES

The third order nonlinearity susceptibility is obtained as a function of wavelength for ZnS/CdSe/ZnS and CdSe/ ZnS/ CdSe structures and these susceptibilitiesare compared together. Numerical calculations show the nonlinear susceptibility of each structure depends on parameters such as structure size,relaxation timeand pump photon energy. The intensity and position of third order nonlinearity susceptibility peak depends on shell thicknesses; smaller thicknesses offirst shell in ZnS/CdSe/ZnS structure has peak susceptibility with lower intensity at shorter wavelength but smaller thicknesses of first shell inCdSe/ZnS/CdSe structure has peak susceptibility with higher intensity with shorter wavelength. The third-order nonlinearity susceptibility peak inZnS/CdSe/ZnS structure than other one is located in shorter wavelength.