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Time and Frequency

Miniaturizing atomic clocks and related technologies to the chip scale promises to improve timekeeping, navigation and communications. In addition, the portability of chip-scale technologies potentially opens up exciting new applications such as GPS backup systems and mineral exploration.

Kitching with an atomic clock
NIST physicist John Kitching displays the heart of a chip-scale atomic clock.
Credit: ©Geoffrey Wheeler

Super-accurate atomic time finds its way into our smartphones, financial transactions and directions that we get from the Global Positioning System (GPS), which relies on the microwave signals from atomic clocks that orbiting satellites transmit. But the frequency used to set official time — 9.2 gigahertz (GHz), about five times higher than an average 4G cellphone — is way too low for future needs. 

Optical atomic clocks promise to serve those needs, as they use higher-frequency light signals. Such clocks have now been miniaturized to the chip scale and can keep more precise time than conventional atomic clocks.

Click on the boxes below to explore the technology in more detail.  

Chip-Scale Clocks Atomic GyroscopesOptical Clock With Integrated Photonics

Created December 11, 2019, Updated September 30, 2025
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