Measurement of the scalar polarizability of the indium $6p_{1/2}$ state using two-step atomic-beam spectroscopy

TL;DR

This study precisely measured the Stark shift in indium's $6p_{1/2}$ state using two-step laser spectroscopy, determining its scalar polarizability and hyperfine splitting, aligning well with theoretical predictions.

Contribution

First precise measurement of the scalar polarizability of indium's $6p_{1/2}$ state using two-step spectroscopy and improved hyperfine splitting data.

Findings

Scalar polarizability $oldsymbol{7683 ext{ a}_0^3}$ with uncertainty 43.

Hyperfine splitting of the $6p_{1/2}$ state improved.

Results agree with recent theoretical calculations.

Abstract

We have completed a measurement of the Stark shift within the $^{115}$In $6s_{1/2} \rightarrow 6p_{1/2}$ excited-state transition using two-step laser spectroscopy in an indium atomic beam. Combining this measurement with recent experimental results we determine the scalar polarizability, $\alpha_{0}$, of the $6p_{1/2}$ state to be $7683 \pm43 \,a_{0}^{3}$ in atomic units, a result which agrees very well with recent theoretical calculations. In this experiment, one laser, stabilized to the $5p_{1/2} \rightarrow 6s_{1/2}$ 410~nm transition, was directed transversely to the atomic beam, while a second, overlapping laser was scanned across the 1343~nm $6s_{1/2} \rightarrow 6p_{1/2}$ transition. We utilized two-tone frequency-modulation spectroscopy of the infrared laser beam to measure the second-step absorption in the interaction region, where the optical depth is less than 10$^{-3}$. In the course of our experimental work we also determined the hyperfine splitting within the $6p_{1/2}$ state, improving upon the precision of an existing measurement.