High-performance, compact optical standard

TL;DR

This paper presents a compact, high-performance optical frequency standard using a microfabricated Rb vapor cell and a low-noise laser, achieving remarkable stability suitable for SI meter realization or atomic clock applications.

Contribution

It introduces a novel, compact optical standard with high stability based on microfabricated Rb vapor cells and two-photon transition spectroscopy.

Findings

Achieves instability of 1.8x10^{-13}/√τ for <100s

Flicker noise floor of 1x10^{-14} out to 6000s

Retrace of 5.7x10^{-13} after 30 hours

Abstract

We describe a high-performance, compact optical frequency standard based on a microfabricated Rb vapor cell and a low-noise, external cavity diode laser operating on the Rb two-photon transition at 778 nm. The optical standard achieves an instability of 1.8x10$^{-13}$/$\sqrt{\tau}$ for times less than 100 s and a flicker noise floor of 1x10$^{-14}$ out to 6000 s. At long integration times, the instability is limited by variations in optical probe power and the AC Stark shift. The retrace was measured to 5.7x10$^{-13}$ after 30 hours of dormancy. Such a simple, yet high-performance optical standard could be suitable as an accurate realization of the SI meter or, if coupled with an optical frequency comb, as a compact atomic clock comparable to a hydrogen maser.