Researchers from NIST and Caltech have developed a new atomic clock design based on a chip-scale frequency comb, or microcomb. This microcomb clock is the first demonstration of all-optical control of the microcomb and its accurate conversion of optical frequencies to lower microwave frequencies.
The new clock architecture could eventually be used to create portable tools for calibrating frequencies in advanced telecommunications systems, radar, navigation, and scientific instruments. The technology has potential to combine good timekeeping precision with very small size, possibly becoming a component of future “NIST on a chip” technologies offering multiple measurement methods and standards in a portable form.
The microcomb clock uses a laser to excite a 2-millimeter-wide silica glass disk to generate a frequency comb, which is then broadened using nonlinear fiber and stabilized to energy transitions in rubidium atoms that “tick” at optical frequencies. The comb converts these optical frequency ticks to the microwave domain, resulting in an output that is 100 times more stable than the intrinsic ticking of the rubidium atoms.
The microcomb chip was made using conventional semiconductor fabrication techniques and could potentially be mass produced and integrated with other chip-scale components. NIST researchers expect that, with further research, the microcomb clock architecture can achieve substantially better performance in the future.
Source: https://www.nist.gov/news-events/news/2014/07/comb-chip-powers-new-nistcaltech-atomic-clock-design
Keywords: Metrology, Frequency, Combs, Atomic, Precision
