Holographically controlled three-dimensional atomic population patterns

TL;DR

This paper demonstrates the creation of three-dimensional atomic population patterns in rubidium vapour using holographically shaped laser beams, with implications for atomic memory design.

Contribution

It introduces a method for shaping 3D atomic populations via optical depletion with holographic control, simplifying previous coherent optical process approaches.

Findings

Reconstructed atomic population structures are largely complementary to control beam intensity.

Repopulation processes cause blurring, limiting resolution.

Modeling these mechanisms helps define future atomic memory design criteria.

Abstract

The interaction of spatially structured light fields with atomic media can generate spatial structures inscribed in the atomic populations and coherences, allowing for example the storage of optical images in atomic vapours. Typically, this involves coherent optical processes based on Raman or EIT transitions. Here we study the simpler situation of shaping atomic populations via spatially dependent optical depletion. Using a near resonant laser beam with a holographically controlled 3D intensity profile, we imprint 3D population structures into a thermal rubidium vapour. This 3D population structure is simultaneously read out by recording the spatially resolved fluorescence of an unshaped probe laser. We find that the reconstructed atomic population structure is largely complementary to the intensity structure of the control beam, however appears blurred due to global repopulation processes. We identify and model these mechanisms which limit the achievable resolution of the 3D atomic population. We expect this work to set design criteria for future 2D and 3D atomic memories.