High precision measurements of hyperfine structures near 790 nm of I 2

High precision measurements of hyperfine splittings of rovibrational lines of the (ν′-ν″)=(0–15) band of the B0 u + — X0 g + transition of I 2 were performed in the near infrared around 790 nm using spectrally narrowed diode lasers. Rotational states with J″ between 0 and 99 were investigated and hyperfine parameters could be derived for the two electronic states separately. For the first time the rotational variation of the quadrupole and the spin-rotational hyperfine coupling parameters could be determined for I 2. A relation is given, by which the hyperfine parameters for a rotational line of the (0–15) band can be predicted, and by which hyperfine splittings of this band can be calculated with an uncertainty of less than 100 kHz for 16 ≤ J″ ≤ 99.