PRESS RELEASE - Optical frequency measurements at the 20th decimal place within minutes

Optical clocks are at the verge of taking over the definition of the international time standard. Within the last year only, several research labs around the earth have successfully demonstrated contribution to international atomic time standard (TAI) using optical transitions in trapped atoms. The swinging of this “optical pendulum” is more than 10,000 times faster than that of today’s atomic clocks. Such a high frequency can be measured using an optical frequency comb, a stabilized laser emitting very regular pulses. The regularity of the pulses determines the optimum level of stability that can be gained from the optical clock. In a recent publication from M. Giunta et al. which appeared in Nature Photonics, researchers from Menlo Systems and from the Max-Planck-Institute of Quantum Optics (MPQ), both in Germany, describe a novel frequency comb system that allows to assess optical frequencies with an accuracy of remarkable 19 decimal places within only one minute, and even surpass the 20th decimal place within a day’s measurement time. Compared with the precision of the best optical clock measurements to date, moving towards the range of 19 decimal places, the laser comb system is ready to cover the next decade of optical clock development. The system is commercially available as FC1500-ULNplus. The publication can be freely assessed online at