Linear and nonlinear intersubband optical properties in a triangular quantum ring

Using the effective mass approximation, within the plane wave expansion, the linear and nonlinear coefficients absorption and the refractive index changes relative to the intersubband transitions in the conduction band of an AlxGa1−xAs/ GaAs/AlxGa1−xAs triangular quantum ring for an x-polarization and an y-polarization of the incident light are calculated. It is found that the transition energy between the ground state and the first two excited states and their related optical matrix are strongly influenced by the length of the side of the inner triangle, leading to a red-shift and blue-shift of the resonant peaks of the intersubband optical absorption, for an x-polarized light absorption and an y-polarized light absorption respectively. Our results are qualitatively similar to those of a triangular quantum wire in the presence of an intense laser field in recent literature.