Hyperfine-structure splitting of the 716 nm R(90)3–10 molecular iodine transition

Abstract

We report on the hyperfine-structure splitting of the 716 nm R903-10 molecular iodine transition. We show that this particular iodine line provides a very useful frequency reference in the context of a laser cooling experiment of iron atoms, an atomic species that has so far never been laser cooled and trapped to our knowledge. We provide experimental values for the hyperfine constants ΔeQq and ΔC of the investigated iodine transition. Dispersive signals of this transition are also presented and used to lock the frequency of a Ti:sapphire laser. The reported stabilization performance is fully compatible with the requirements of a laser cooling experiment of iron atoms.

Isotope shifts and hyperfine structure of the laser-cooling Fe I 358-nm line

“…In this paper, we have reported at the third percent level the first experimental determination of the isotope shifts of the 3d 7 4s a 5 F 5 − 3d 7 4p z 5 G o 6 Fe I line at 358 nm between all four stable isotopes 54 Fe (I = 0), 56 Fe (I = 0), 57 Fe (I = 1/2) and 58 Fe (I = 0), as well as the hyperfine structure of that line for 57 Fe. The knowledge of these frequency shifts is of primary importance in the context of any laser cooling experiment for iron atoms since the Fe I 358-nm line has been identified as the first accessible iron transition suitable for that purposes [2]. A King plot analysis has further yielded the field and specific mass shift coefficients of the transition.…”

“…The hyperfine structure of the R(90)3 − 10 iodine tran-arXiv:1507.01498v1 [physics.atom-ph] 6 Jul 2015 sition was studied in details in Ref. [2]. A description of the saturation spectroscopy setup can be found in this reference and will not be repeated here.…”

“…Three electric dipole transitions are associated to this hyperfine structure, as shown in Fig. 3 with the labels (1), (2) and (3). The relative theoretical intensities of these three hyperfine transitions are 100 : 84.4 : 1.3, respectively [11].…”

“…If several atomic species can be nowadays laser cooled using well established laser schemes, still most have never been manipulated in this way, essentially because of a lack of suitable and affordable laser radiation. In this framework, an innovative cooling scheme for iron atoms has been recently proposed on the basis of 2 ultraviolet transitions at 372 and 358 nm, both accessible with commercial laser systems [2]. Iron atom is a quite challenging atomic species for laser cooling.…”

“…2, recorded with an isotope-enriched powder of iron. Bottom: Doppler-free laser saturated-absorption spectrum of the 716-nm R(90)3 − 10 molecular iodine transition recorded synchronously with the iron spectrum and used for calibration purposes (see Ref [2]. for the splitting values of all hyperfine components ai (i = 1 − 15) of the transition).…”