Towards Collective Emission Using a Mid-Infrared Transition in Strontium Tweezer Arrays 

We report experimental progress on using a mid-infrared (2923 nm) transition in strontium for the study of collective emission behavior in atomic arrays. We demonstrate the initial steps toward coherent control of strontium between the closed two-level system formed by the 5s5p ³P₂ m_J = |2| and 5s4d ³D₃ m_J = |3| states. Loading the atoms into atomic tweezer arrays generated via holographic metasurfaces [1], we prepare and probe atoms in the ³P₂ state with this transition. We measure the single strontium atom lifetime in the ³D₃ state close to its natural linewidth. With these demonstrations, we establish the necessary building blocks to study collective emission in subwavelength atomic tweezer arrays.