Indirect pumping of alkali-metal gases in a miniature silicon-wafer cell

Atom spin sensors occupy a prominent position in the landscape of quantum technology, as they can combine precise measurements with appealing miniature packages that are crucial for many applications. In this work, we report on the design and realization of miniature silicon-wafer cells, with a double-chamber configuration and integrated heaters. The cells are tested by our systematically studying the dependence of the spin dynamics on the main pump parameters, temperature, and bias magnetic field. The results are benchmarked against centimeter-sized paraffin-coated cells, which allows optimization of the operating conditions of a radio frequency–driven atomic magnetometer. In particular, we observe that, when indirect optical pumping is performed on the two cells, an analogous line-narrowing mechanism appears in otherwise-very-different cell conditions. Competitive results are obtained, with magnetic resonance linewidths of roughly 300 Hz at the maximum signal-to-noise ratio, in a nonzero-magnetic-field setting, and in an atomic shot noise–limited regime.