Intersubband resonant enhancement of the nonlinear optical properties in asymmetric (CdS/ZnSe) based quantum wells

In this work, the linear and nonlinear optical properties are studied theoretically in asymmetric (CdS/ZnSe/BeTe)/(ZnSe/BeTe) quantum wells. The electronic states are calculated using the envelope wave function approximation and the intersubband transition energies are studied as a function of CdS and ZnSe well thicknesses as well as doping concentration. The optimum parameters carrying out the transition energy 0.8 eV (1.55 μm wavelength) are given. Results are presented for the linear, the third order nonlinear optical absorption and the refractive index changes in the studied heterostructure. Results show that the changes in the linear and the third order nonlinear optical absorption as well as refractive index change are as important as the temperature is high, the nonlinear terms must be taken into consideration especially near the resonance.

► Our asymmetric quantum well structure shows important nonlinear optical properties. ► The well thickness, doping and optical intensity are optimized to achieve the 1.55 μm wavelength ISBT. ► The changes in the linear and nonlinear optical absorption as well as refractive index are studied. ► The nonlinear term must be taken into consideration especially near the resonance.