Batch-fabrication of all-dielectric vapor cells enabling optically addressed Rydberg atom electrometry
Millimeter-scale atomic vapor cells can be accurately and economically batch-fabricated by anodically bonding silicon and glass wafers, enabling the manufacturing of miniature atomic clocks and quantum sensors. However, silicon's high dielectric constant and conductive losses at millimeter wave frequencies limit its suitability for Rydberg-atom electrometry, which enables highly sensitive electric-field measurements by exploiting the extreme polarizability of Rydberg states in alkali atoms. To address this, we present an all-glass wafer-level microfabrication process that eliminates silicon, creating hermetically sealed vapor cells that are stable over long timelines with embedded cesium dispensers. Femtosecond laser machining precisely defines the cell geometry, and laser-activated alkali loading ensures reliable filling. We demonstrate long-term vacuum stability and robust Rydberg excitation through electromagnetically induced transparency measurements. We then use these cells to measure a 34 GHz millimeter wave field resonant with the $58D_{5/2}\rightarrow 60P_{3/2}$ transition using Autler-Townes splitting and observe the expected linear dependence with field strength. This work demonstrates that the all-glass bonding approach offers a highly durable low-loss cell alternative for miniaturized millimeter wave and microwave quantum sensing, with the potential to flexibly incorporate a range of other dielectric and semiconductor materials and integrate with photonic and electronic technologies.