Chip-Scale Atomic Birefringent Diffractive-Optical-Elements

Abstract: The interaction between light and vapors in the presence of magnetic fields is fundamental to many quantum technologies and applications. Recently, the ability to geometrically confine atoms into periodic structures has enabled the creation of chip-scale, micromachined hybrid atomic-diffractive optical elements. However, applying magnetic fields to such structures remains largely unexplored, offering potential for both fundamental and applied insights. Here, we present measurements of an atomic-diffractive optical element subject to magnetic fields. In contrast to the well-known polarization rotation in a Faraday medium, these diffractive atomic elements exhibit additional, rapidly oscillating rotation terms, which we validate both theoretically and experimentally. Moreover, we find that the introduction of spatially varying magnetic fields leads to a reduction in fringe visibility, which can be leveraged for gradiometric applications. Together, these effects establish a chip-scale platform where diffraction and quantum sensing are inseparably co-engineered, unveiling previously inaccessible regimes of atom-photon-magnetic interaction. By probing the magneto-optic response of periodically confined vapors, our results lay the groundwork for integrated smart-cell magnetometers and open new avenues for flat-optics-enabled quantum photonic devices.