Vibronic spectroscopy of sympathetically cooled CaH$^+$

TL;DR

This study measures vibronic transitions in CaH$^+$ using resonance-enhanced photodissociation, providing spectral data that supports future high-resolution spectroscopy for applications in astrochemistry and precision measurement.

Contribution

It reports the first measurement of specific vibronic transitions in CaH$^+$ via resonance-enhanced photodissociation with co-trapped laser-cooled Ca$^+$, aligning with theoretical predictions.

Findings

Observed four vibrational resonances from v=0 to v'=1-4.

Good agreement between experimental results and simple theoretical model.

Identified limitations due to laser mode-locked excitation.

Abstract

We report the measurement of the 1$^{1}\Sigma\longrightarrow$ 2$^{1}\Sigma$ transition of CaH$^+$ by resonance-enhanced photodissociation of CaH$^+$ that is co-trapped with laser-cooled Ca$^+$ . We observe four resonances that we assign to transitions from the vibrational $v$=0 ground state to the $v'$=1-4 excited states based on theoretical predictions. A simple theoretical model that assumes instantaneous dissociation after resonant excitation yield results in good agreement with the observed spectral features except for the unobserved $v'$=0 peak. The resolution of our experiment is limited by the mode-locked excitation laser, but this survey spectroscopy enables future rotationally resolved studies with applications in astrochemistry and precision measurement.