Ivan Sherstov, Timur Abbasov researchers at the laboratory for time and frequency research Skoltech Digital Engineering Center published an article “Toward a New Generation of Compact Transportable Yb+ Optical Clocks” in the journal “Selected Papers on Lasers, Accelerators, and Optics to Celebrate the 100th Anniversary of the Birth of N.G. Basov”.

The most compact in the world at the moment optical frequency standard based on an Yb ion.

Optical atomic clocks are currently one of the most sensitive tools making it possible to precisely test the fundamental symmetry properties of spacetime and Einstein’s theory of relativity. At the same time, the extremely high stability and accuracy of compact transportable optical clocks open new perspectives in important fields, such as satellite navigation, relativistic geodesy, and the global time and frequency network. Our project aimed to develop a compact transportable optical clock based on a single ytterbium ion. We present the first prototype of the Yb+ clock (298 kg in 1 m3) and present several solutions aimed to improve the clock’s robustness to approach the demands of a space-qualified system. We present spectroscopic studies of a 435.5 nm quadrupole clock transition with Fourier-limited spectra of 25 Hz. The estimated instability of the output frequency at 1 GHz, which was down-converted with an optical frequency comb (OFC), is at the level of 9×10−15/τ−−√, and the long-term instability and inaccuracy are at the level of 5×10−16. As the next steps, we present a new design for the clock laser and the OFC.

📄 The full text of the article is available at link (https://www.mdpi.com/2073-8994/14/10/2213/htm).