Low-power, miniature 171Yb ion clock using an ultra-small vacuum package

We report a demonstration of a very small microwave atomic clock using the 12.6 GHz hyperfine transition of the trapped 171Yb ions inside a miniature, completely sealed-off 3 cm3 ion-trap vacuum package. In the ion clock system, all of the components are highly miniaturized with low power consumption except the 369 nm optical pumping laser still under development for miniaturization. The entire clock, including the control electronics, consumes <300 mW. The fractional frequency instability of the miniature Yb+ clock reaches the 10−14 range after a few days of integration.