Measurement of hyperfine structure within the6P3/2excited state ofI115n

Abstract

Using a two-step, two-color laser spectroscopy technique, we have completed a measurement of the hyperfine structure within the $(5{s}^{2}6p)$ ${^{2}P}_{3/2}$ excited state in $^{115}\text{I}\text{n}$ $(I=9/2)$. A frequency stabilized GaN diode laser at 410 nm is locked to the $5{P}_{1/2}\ensuremath{\rightarrow}6{S}_{1/2}$ ground-state transition and a second 1291 nm diode laser is scanned over the $6{S}_{1/2}\ensuremath{\rightarrow}6{P}_{3/2}$ transition to produce hyperfine spectra for the $6{P}_{3/2}(F=3,4,5,6)$ manifold. We find the hyperfine splittings of consecutive sublevels to be as follows: $\ensuremath{\Delta}{\ensuremath{\nu}}_{4\ensuremath{-}3}=275.25(42)\text{ }\text{MHz}$, $\ensuremath{\Delta}{\ensuremath{\nu}}_{5\ensuremath{-}4}=384.05(71)\text{ }\text{MHz}$, and $\ensuremath{\Delta}{\ensuremath{\nu}}_{6\ensuremath{-}5}=517.48(44)\text{ }\text{MHz}$. The magnetic dipole, electric quadrupole, and magnetic octupole hyperfine coupling constants derived from these three splittings are, respectively, $a=79.33(7)\text{ }\text{MHz}$, $b=62.5(5)\text{ }\text{MHz}$, and $c=\ensuremath{-}0.04(4)\text{ }\text{MHz}$. The measured value of the dipole constant, $a$, agrees to within 2% with a recent theoretical prediction.