Doppler-free high resolution continuous wave optical UV-spectroscopy on the $\mathrm{A}\,^2\Sigma^+ \leftarrow \mathrm{X}\,^2\Pi_{3/2}$ transition in nitric oxide

TL;DR

This paper demonstrates Doppler-free continuous-wave UV spectroscopy of nitric oxide, resolving hyperfine structures and refining molecular constants with high precision, confirming previous quantum beat spectroscopy results.

Contribution

It provides high-resolution measurements of nitric oxide's hyperfine structure and updates molecular constants using Doppler-free UV spectroscopy, enhancing spectroscopic accuracy.

Findings

Resolved hyperfine structure of nitric oxide transition

Compared experimental splittings with calculations

Refined molecular constants for the A2Σ+ state

Abstract

We report on Doppler-free continuous-wave optical UV-spectroscopy resolving the hyperfine structure of the $\mathrm{A}\,^2\Sigma^+ \leftarrow \mathrm{X}\,^2\Pi_{3/2}$ transition in nitric oxide for total angular momenta $J_X=1.5-19.5$ on the $\mathrm{oP_{12ee}}$ branch. The resulting line splittings are compared to calculated splittings and fitted determining new values for the molecular constants $b, c, eQq_0$ and $b_F$ for the $\mathrm{A}\,^2\Sigma^+$ state. The constants are in good agreement with values previously determined by quantum beat spectroscopy.