Atomic vapor cells fabricated by femtosecond laser welding of standard-optical-quality glass
in: Optics Express (2026)
A simple two-step method produces quasi-monolithic all-glass atomic vapor cells. First, optical contact bonding of standard-optical-quality glass components under vacuum or buffer-gas atmosphere achieves initial hermetic sealing at room temperature. Second, femtosecond laser spot welding along the bond interface provides long-term mechanical and thermal stability, yielding a 14-fold increase in tensile strength compared to pure optical contact bonding. Demonstrated geometries include cylindrical and cubic cells with sidewall widths as low as 2 mm. Stacking and welding multiple machined glass substrates with different structures enables a wide variety of cell designs. Cesium D1 absorption spectroscopy confirms hermetic sealing and excellent long-term stability over 10 months, with no detectable gas ingress or cesium loss. The low-temperature process avoids elevated temperatures, allowing future integration of sensitive interior coatings (e.g., paraffin or silane films) to enhance spin coherence for quantum sensing applications.
DOI: 10.1364/OE.599467