Microfabricated vapor cells for miniature atomic clocks based on post-sealing activated cesium dispensers

We report techniques based on cesium dispensers to fill microfabricated vapor cells for miniature atomic clocks applications. Two main types of dispensers are considered, which take the form of pills or paste. Whereas the pill contains a large quantity of Cs, the paste is more compatible with wafer-level fabrication. In both cases, the main advantage is the release of the cesium vapor only once the cell has been sealed, ensuring an optimal cell fabrication. Activation is thus performed through local heating of the dispenser with a laser. Cells using both dispenser types are shown to be compatible with atomic clocks requirements, namely a clock frequency instability below 1 × 10 −11 at one day integration time.