Combined error signal in Ramsey spectroscopy of clock transitions

TL;DR

This paper introduces a universal Ramsey spectroscopy method using a combined error signal that effectively eliminates probe-induced light shifts and is simpler than previous techniques, enhancing atomic clock stability.

Contribution

The authors present a novel, simplified approach to atomic clock stabilization employing a combined error signal from two Ramsey periods, improving robustness and ease of implementation.

Findings

Eliminates probe-induced light shifts effectively.

Does not suffer from relaxation or pulse fluctuation effects.

Uses a single error signal for feedback, simplifying the process.

Abstract

We have developed a universal method to form the reference signal for the stabilization of arbitrary atomic clocks based on Ramsey spectroscopy. Our approach uses an interrogation scheme of the atomic system with two different Ramsey periods and a specially constructed combined error signal (CES) computed by subtracting two error signals with the appropriate calibration factor. CES spectroscopy allows for perfect elimination of probe-induced light shifts and does not suffer from the effects of relaxation, time-dependent pulse fluctuations and phase-jump modulation errors and other imperfections of the interrogation procedure. The method is simpler than recently developed auto-balanced Ramsey spectroscopy techniques [Ch. Sanner, et al., Phys. Rev. Lett. 120, 053602 (2018); V. I. Yudin, et al., Phys. Rev. Appl. 9, 054034 (2018)], because it uses a single error signal that feeds back on the clock frequency. CES universal technique can be applied to many applications of precision spectroscopy.