Laser magnetic resonance measurement of rotational transitions in the metastable a1Δg state of oxygen

Abstract Laser magnetic resonance (LMR) for five rotational transitions, J = 4 ← 3, 5 ← 4, 7 ← 6, 8 ← 7, 9 ← 8, of the oxygen molecule 16 O 16 O in its metastable state, a 1 Δ g , v = 0, are observed using six fir laser lines. Taking the known values of the g factors, their zero-field frequencies are obtained as 340.0085(6), 424.9810(9), 594.870(1), 679.780(1), and 764.658(1) GHz, respectively. They are fit by ( E h ) = B 0 [J(J + 1) − 4] + D 0 [J(J + 1) − 4] 2 + (−1) J ( 1 2 )qJ (J + 1)[J(J + 1) − 2] , where B 0 = 42.50457(10) GHz, D 0 = 153.14(110) kHz, and q = 0.050(90) kHz.