Measurement of the Raman polarizability anisotropy for the v = 1 pure rotational Raman transition in H 2 by rotational Raman spectroscopy

A combination of stimulated Raman pumping and rotational Raman spectroscopy is used to accomplish the first measurement of the polarizability anisotropy γ_11,13 (355 nm) for the S₁₁ (1) transition in molecular hydrogen H₂. Saturation of the Q₀₁(1) transition connecting the |X¹ Σ⁺ _g, v = 0, J = 1 > state to the |X¹ Σ⁺ _g, v = 1, J = 1 > state in H₂ by stimulated Raman pumping is the critical element in this experiment. The observed intensities of the rotational Raman lines for these states allow an estimate of γ_11,13 (355 nm) as 0.358 ± 0.004 ų. A comparison of this value to that obtained from fundamental ab initio calculations in H₂ also is possible for the first time.