Abstract
The intersubband transition at 1.55 mu m wavelength has been demonstrated theoretically in asymmetric II-VI double quantum wells heterostructures consisting of a deep CdS well and a shallow ZnSe well coupled by a thick BeTe barrier. The intersubband transition allows ultra fast relaxation time. The asymmetric geometry reduces the coupling and then lowers the switching energies. The electronic states of these structures are calculated using the envelope wave function approximation. The transition energies have been studied as a function of CdS and ZnSe well thicknesses. Then the linear and nonlinear optical properties such as optical absorption associated with intersubband transitions have been investigated. The optimum parameters of 1.55 mu m photo detector have been determined at 300 K.