Doppler-Free Spectroscopy of Molecular Iodine Near 532 nm

Molecular Iodine exhibits a very rich absorption spectrum1 near 532 nm. Frequency-doubled monolithic diode laser pumped Nd:YAG lasers, having narrow linewidths and relatively wide tuning range, provide an excellent tool to investigate these transitions. Furthermore, we have recently shown that the Nd:YAG laser frequency can be absolutely stabilized to the Doppler-free lines of Iodine2. In this paper we utilize the ability to lock two lasers to Iodine hyperfine transitions in order to measure precisely the hyperfine frequency splitting by heterodyne spectroscopy. These results are then used to determine the hyperfine constants of the measured transitions.