Two-dimensional realization of electromagnetically induced phase grating in a quantum dot nanostructure

Abstract

In this paper a novel method for electromagnetically induced phase grating in a quantum dot nanostructure is proposed. The four-level quantum dot nanostructure which is designed by solving the Schrödinger and Poisson equations. By size control of quantum dot and external voltage, one can obtain appropriate energy levels which can be interacted by four-optical fields. In this case, a probe, a two-dimensional standing wave and a driving field simultaneously interact by quantum dot for creation of coherent population trapping. A terahertz (THz) signal can influence the electron population in dark and bright levels, therefore optical susceptibility and transmission spectrum of probe field in the medium can be altered. In the presence of the THz field, the medium becomes phase dependent and this makes more of probe energy transfer to the higher order of the diffraction.