Gain-phase grating via double tunneling in quantum dot molecules

Abstract

The scheme for gain-phase grating is proposed via double tunneling effect in the quantum dot molecules system with five-level structure, which is formed by two quantum dots due to inter-dot tunneling. Combining the stranding-wave control field with the double tunneling effect, the weak probe field could be diffracted to the high-order direction with the strong diffraction intensity. In the presence of double tunneling, the gain accompanied with the certain dispersion occurs, which is responsible for the preparation of the high-efficiency grating. It is found that the first-, second-, and other-order diffraction intensities are simultaneously higher than the central intensity and the diffraction intensities could be controlled by adjusting the parameters such as tunneling intensities, interaction length, probe detuning, relative phase and Rabi frequencies of external fields. The scheme we present can be utilized to develop a new photonic device for optical network and communication.