Intensity effects of light coupling to one or two atom arrays

Recent predictions[1,2] of perfect reflection of light from single layer atom arrays inspired many different theoretical and experimental investigations of this system. Most studies are in the weak laser limit where the harmonic approximation for the atom states holds well. We focus on how this system behaves as the intensity of the incident light is increased and the weak laser approximation progressively fails. Simulations are performed for both single arrays and a pair of parallel arrays in a geometry that leads to a resonant cavity for the light. We study how the reflected, transmitted, and incoherently scattered probabilities depend on detuning and intensity. For the cavity geometry, the weak laser approximation fails at very small intensities. Calculations are performed for both infinite arrays and finite size arrays. We also investigate the behavior of the photon statistics as embodied in g(2) functions.

[1] R. J. Bettles, S. A. Gardiner, and C. S. Adams, “Enhanced optical cross section via collective coupling of atomic dipoles in a 2d array,” Phys. Rev. Lett. 116, 103602 (2016).

[2] E. Shahmoon, D. S. Wild, M. D. Lukin, and S. F. Yelin, “Cooperative resonances in light scattering from two-dimensional atomic arrays,” Phys. Rev. Lett. 118, 113601 (2017).