Caesium atomic clocks are one of the most accurate time and frequency standards, and serve as the primary standard for the definition of the second in the International System of Units (SI), the modern metric system.

The main variety of atomic clock uses caesium atoms cooled to temperatures that approach absolute zero. The primary standard for the United States, the National Institute of Standards and Technology (NIST)'s caesium fountain clock named NIST-F2, measures time with an uncertainty of 1 second in 300 million years (relative uncertainty 10 −16 ...

To create a clock, cesium is first heated so that atoms boil off and pass down a tube maintained at a high vacuum. First they pass through a magnetic field that selects atoms of the right energy state; then they pass through an intense microwave field.

With technology that guarantees phenomenal accuracy, performance levels exceeding ITU-T G.811/Stratum 1 PRC, a long-life 10-year cesium tube all in an extremely compact size, our cesium clocks are at the very top of the class.

2025年3月10日 · We realize a high-performance compact optically pumped cesium beam atomic clock utilizing the Faraday laser simultaneously as the pumping and detection lasers. The Faraday laser, which is frequency stabilized by the modulation transfer spectroscopy (MTS) technique, has a narrow linewidth and superior frequency stability.

Cesium beam clocks are the most stable and accurate industrial frequency sources for long-term applications. For decades and among various manufacturers, clocks have traditionally operated by means of magnetic deflection. With the commercial availability of narrow-band laser sources, optical pumping can now replace cesium clock designs.

2024年8月22日 · Indeed, the first practical atomic clocks were beam clocks. They were based on cesium, a soft, gold-colored metal found in the leftmost column of the periodic table. Cesium exists in nature as a soft, silvery-gold metal that can ignite spontaneously in …

With the availability of a new primary frequency standard, NBS-5 at the National Bureau of Standards, we have been able to evaluate with greater confidence than in the past the performance characteristics of the commercial cesium beam clocks used in …

2024年7月8日 · We realize a high-performance compact optically pumped cesium beam clock using Faraday laser simultaneously as pumping and detection lasers. The Faraday laser, which is frequency stabilized by modulation transfer spectroscopy (MTS) technique, has narrow linewidth and superior frequency stability.

Cesium beam clocks have long stood as the pinnacle of precision in timekeeping. These clocks, which have their foundation in the International System of Units (SI) definition of a second, rely on the oscillations between hyperfine levels of cesium 133 (133Cs) atoms.