The world’s smallest atomic clock

Ray LaPierre

Li-Na Bai, Yuanhong Cao, Leiji Liu +3 more

We introduce a novel waveguide cavity for ultra-miniature cell-type Rb atomic clock. In the cavity, a coupling ring shaped to be a semi-circle imports an rf signal from electronics, a screw regulator acts as a medium coupler to transmit the microwave signal into the absorption cell, and both the parts serve as a filter to suppress useless components except 6.8 GHz. Furthermore, the waveguide cavity can be used to design a miniature Rb atomic clock, and spread it to a chip-scale atomic clock. We have completed the design of the smallest cell-type Rb atomic clock in the world based on this waveguide cavity. It has not only a small size but also obviously better key performances than those of other miniature Rb atomic clocks. This ultra-miniature cell-type Rb atomic clock aging is 4 × 10 −13 /d, which is obviously slower than that of other miniature Rb atomic clocks.

Peter Rodgers, Oliver Graydon

The precision of atomic clocks could soon be available in hand-held devices such as mobile phones, radios and GPS receivers thanks to a breakthrough by physicists in the US. John Kitching and colleagues at the National Institute of Standards and Technology (NIST) in Boulder, Colorado, have built a physics package – the components that lie at the heart of an atomic clock – with a volume of just 9.5 mm3. This is about 100 times smaller than those of existing atomic clocks.

Sven M. J. Rogge, Matthew J. Sellars

Jun Ye

I will report our recent effort towards realizing the full potential of a many-particle clock with a state-of-the-art stable laser. We have achieved fractional stability of 2.2 × 10-16 at 1 s for the JILA Sr optical atomic clock. We have also reduced the total uncertainty of our clock to 2.1 × 10-18 in fractional frequency units. Both represent new records for the performance of an atomic clock.

Kurt Gibble