The hyperfine structure of the 1 3Δg state of Na2

Abstract

The hyperfine spectra of the Na 2 1 3 ⌬ g state have been recorded with sub-Doppler continuous wave ͑CW͒ perturbation facilitated optical-optical double resonance ͑PFOODR͒ spectroscopy viaThe rotational lines into the Nϭ14-51 levels of the 1 3 ⌬ g state observed previously ͓J. Mol. Spectrosc. 134, 50 ͑1989͔͒ have four components for transitions between symmetric rotational levels or five components for transitions between antisymmetric rotational levels and the hyperfine coupling belongs to Hund's case b ␤S . For the low-N levels observed later, however, the hyperfine spectra are much more complicated. We have worked out the matrix elements of the molecular Hamiltonian in the case b ␤S basis. After taking into consideration spin-orbit, spin-spin, and spin-rotation interactions, we obtained a set of molecular constants for the Na 2 1 3 ⌬ g state, with which we can reproduce the hyperfine spectra of both highand low-N rotational levels.

Experimental study of the NaK 3Π3 double minimum state

“…With the use of narrow-band continuous-wave ͑cw͒ lasers, the PFOODR method is inherently Doppler-free, leading to very high resolution excitation spectra. Previous experiments using this method have focused primarily on the homonuclear diatomic molecules, Li 2 , 1-10 Na 2 , 8,[11][12][13][14][15][16][17][18][19][20][21] and K 2 , [22][23][24][25] and to a lesser extent on the heteronuclear molecules NaK ͑Refs. 26 and 27͒ and 6 Li 7 Li.…”

The Na2 2Πg3 state: New observations and hyperfine structure

“…1 The unique advantage of this technique is to be able to reach the high-lying triplet states, Rydberg states as well as doubly excited states, from the singlet ground state via the A 1 ⌺ u + ϳ b 3 ⌸ u mixed intermediate levels. CW PFOODR excitation spectroscopy has a sub-Doppler resolution and hyperfine structures ͑HFS͒ of triplet Rydberg states of Na 2 , [4][5][6]11,12,23,24,26,28 Li 2 ,[34][35][36][37][38] and NaK ͑Refs. 2 Since then both CW PFOODR and pulsed PFOODR excitations have been applied and many triplet states of Na 2 have been observed.…”