Efficient beam spatial profiles via three-wave mixing in tunneling quantum dots

Abstract

This paper explores the effects of orbital angular momentum (OAM) and phase sensitivity in Three-Wave Mixing (TWM) processes within a quantum dot (QD) system. We analyze the efficiency, spatial, and phase characteristics of the generated TWM beam as influenced by varying control beam parameters. Our results demonstrate that the efficiency of the TWM beam exhibits a double-peak structure, with increased tunneling enhancing the efficiency at detuning values away from resonance. Additionally, the evolution of efficiency during beam propagation shows distinct behaviors depending on the tunneling parameter, with larger values initially increasing efficiency before slightly decreasing, while smaller values result in a steady increase. The phase sensitivity of the QD system allows for spatially dependent effects, as evidenced by the control beam's spatial profile being transferred to the generated TWM beam. The intensity profiles reveal that a Gaussian control beam results in a central peak, whereas vortex beams with nonzero OAM induce doughnut-shaped intensity profiles with zero central intensity. The observed phenomena are attributed to the closed-loop structure of the QD system enabled by electron tunneling, which preserves and transfers the spatial and phase attributes of the control beam to the TWM beam. These findings highlight the potential for precise control over TWM beams through phase and spatial modulation, with implications for advanced optical applications such as beam shaping, imaging, and communication.