Nonlinear intersubband absorption and refractive index change in n-type δ-doped GaAs for different donor distributions

Abstract

In this study, both the linear and nonlinear intersubband optical absorption coefficients and the refractive index changes are calculated for the uniform, triangular and Gaussian-like donor distribution. The Gaussian-like distribution differs from the Gaussian distribution other authors use. The electronic structure of n-type Si δ-doped GaAs has been theoretically calculated by solving the Schrödinger and Poisson equations self-consistently. Our results show that the location and the size of the linear and total absorption coefficients and refractive index changes depend on the donor distribution type. The shape of δ-effective potential profile and the subband properties are changed as dependent on the donor distribution model. Therefore, the variation of the absorption coefficients and refraction index changes, which can be appropriate for various optical modulators and infrared optical device applications can be smooth obtained by the alteration donor distribution model.