Controlling 2D-fraunhofer diffraction in nonlinear optomechanical systems with atomic ensembles

Abstract In this letter, we propose a novel nonlinear optomechanical system for generating a two-dimensional (2D) optical grating. The system comprises a Fabry–Pérot cavity with a fixed mirror, movable end mirror, degenerate optical parametric amplifier (OPA), and ensemble of identical two-level atoms. By applying a 2D asymmetric standing wave as the driving field, the probe light can be diffracted in the x - and y -directions with different intensities, leading to an asymmetric optomechanically induced grating. The amplitude and phase modulations of the output probe light and the resulting Fraunhofer diffraction patterns were investigated. The results show that the atomic ensemble plays a crucial role in controlling the efficiency and asymmetry of 2D gratings. We demonstrate that by tuning the nonlinear gain of the OPA and higher-order excitations of the atoms, the transparency of the medium can be enhanced, leading to greater transmission of probe energy and transfer to higher diffraction orders. The proposed system offers a novel approach for generating asymmetric 2D optical gratings in optomechanical devices with potential applications in quantum information science.