Single ion spectroscopy of four metastable state clear-out transitions in Yb II: isotope shifts and hyperfine structure

TL;DR

This paper provides detailed spectroscopic data on four metastable state transitions in Yb$^+$ ions, highlighting their isotope shifts, hyperfine structures, and potential advantages for simplifying ion trapping and cooling setups.

Contribution

It reports new spectroscopic measurements of four metastable transitions in Yb$^+$, including isotope shifts and hyperfine structures, proposing alternative transitions for ion cooling and state manipulation.

Findings

Identified two transitions as promising alternatives for standard repumping lasers.

Measured isotope shifts and hyperfine structures for all even isotopes and $^{171}$Yb$^+$.

Provided decay branching ratios for the excited states.

Abstract

We present spectroscopic data for four metastable state clear-out transitions between 399 nm and 412 nm for all even long-lived isotopes of Yb$^+$ as well as their hyperfine structure in $^{171}$Yb$^+$. The strong $^2 \rm{D}_{3/2} \rightarrow {}^1[1/2]_{1/2}$ transition at 412 nm represents an attractive alternative for the standard 935 nm repumper used in cooling and trapping experiments, while the transition to the $^3[3/2]_{3/2}$ state at 411 nm clears out the $^2 $F$_{7/2}$ state, for which typically 638 nm or 760 nm are used. These two alternative transitions simplify the experimental setup by removing the need for infrared optics to cool and manipulate Yb$^+$ and may be of particular interest when considering integrated photonics solutions. We also present data for the transitions $^2 $D$_{3/2} \rightarrow {}^3[1/2]_{3/2}$ at 399 nm, and $^2 $D$_{3/2} \rightarrow {}^1[5/2]_{5/2}$ at 410 nm including decay branching ratios of the excited states.