Measurement of the infrared2F7/2−2D5/2transition in a single171Yb+ion

Abstract

The ${}^{2}{F}_{7/2}(F=3){--}^{2}{D}_{5/2}(F=2)$ 3.43-\ensuremath{\mu}m transition in ${}^{171}{\mathrm{Yb}}^{+}$ has been measured to be 87 366 282 258(91) kHz. This transition is of interest as an infrared frequency standard. A subsidiary measurement of the 3.43-\ensuremath{\mu}m ${(F=4\ensuremath{-}F}^{\ensuremath{'}}=3)$ transition yields a frequency of 87 362 471 500(800) kHz. Taken with a previous measurement of the ${}^{2}{D}_{5/2}$ level hyperfine splitting, a ${}^{2}{F}_{7/2}$ level hyperfine splitting of 3620(2) MHz and an A factor of 905.0(0.5) MHz are deduced. In addition, a 3.43-\ensuremath{\mu}m transition isotope shift of ${v}_{171}--{v}_{172}=+4048(4)\mathrm{MHz}$ is obtained from these experiments and a known value for the transition in the 172 isotope. These measurements taken with previous work give a value for the ${}^{2}{S}_{1/2}(F=0){--}^{2}{F}_{7/2}(F=3)$ electric octupole transition of 642 121 497 308(178) kHz, which will be used as a starting point in the search for this extremely weak transition.