Direct frequency-comb spectroscopy of $6S_{1/2}$-$8S_{1/2}$ transitions of atomic cesium

TL;DR

This paper demonstrates high-precision, Doppler-free two-photon spectroscopy of cesium's $6S_{1/2}$-$8S_{1/2}$ transitions using a frequency comb and coherent control, achieving uncertainties below 5×10⁻¹⁰.

Contribution

It introduces a novel method combining frequency comb spectroscopy with coherent control to measure cesium transitions with unprecedented precision.

Findings

Transition frequencies measured with uncertainty below 5×10⁻¹⁰

Doppler-free absorption achieved via spectral splitting and imaging

Theoretical analysis identifies laser-induced AC Stark shift as main uncertainty source

Abstract

Direct frequency-comb spectroscopy is used to probe the absolute frequencies of $6S_{1/2}$-$8S_{1/2}$ two-photon transitions of atomic cesium in hot vapor environment. By utilizing the coherent control method of temporally splitting the laser spectrum above and below the two-photon resonance frequency, Doppler-free absorption is built in two spatially distinct locations and imaged for high-precision spectroscopy. Theoretical analysis finds that these transition lines are measured with uncertainty below $5\times10^{-10}$, mainly contributed from laser-induced AC Stark shift.