Hyperfine structure in the electronic spectrum of 127I2 by saturated absorption spectroscopy at 633 nm

The full hyperfine components of the R (127) line in the 11-5 band and the 10 components of the P (33) line in the 6-3 band of the B←X electronic transition of 127I2 were observed by the saturated absorption spectroscopy using a complex resonator He-Ne laser. The frequency of the laser was locked to each component and the frequency separations of the components were precisely measured. The hyperfine structure of the R (127) line was compared with a model which included both a nuclear electric quadrupole and magnetic hyperfine interactions.