High-precision measurement of hyperfine structure in the $D$ lines of alkali atoms

TL;DR

This paper reports high-precision measurements of hyperfine structures in the D lines of all natural alkali atoms using laser spectroscopy, significantly improving existing hyperfine coupling constants.

Contribution

It provides the first comprehensive high-resolution hyperfine measurements across all natural alkali atoms' D lines, enhancing the accuracy of hyperfine constants.

Findings

Hyperfine coupling constants are significantly improved.

High-resolution laser spectroscopy effectively resolves hyperfine transitions.

Measurements cover all naturally-occurring alkali atoms.

Abstract

We have measured hyperfine structure in the first-excited $P$ state ($D$ lines) of all the naturally-occurring alkali atoms. We use high-resolution laser spectroscopy to resolve hyperfine transitions, and measure intervals by locking the frequency shift produced by an acousto-optic modulator to the difference between two transitions. In most cases, the hyperfine coupling constants derived from our measurements improve previous values significantly.